Solar panels and payback

[Jeff Layman]

This made some local news here yesterday:
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>

During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it would
be around twice that time.

I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

[alan_m]

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it would
be around twice that time.
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

Possibly it depends on how the cost of the installation was calculated.
Possibly it included the energy company selling carbon credits :)

"The stadium sponsor, Utilita Energy, funded the project"

[The Natural Philosopher]

Post by alan_m

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it
would be around twice that time.
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

Possibly it depends on how the cost of the installation was calculated.
Possibly it included the energy company selling carbon credits :)
"The stadium sponsor, Utilita Energy, funded the project"

Any information regarding 'renewable energy' is 99% guaranteed to be a lie.
Only subsidies make the thing profitable.
And I wouldn't bank on them being around that much longer.
Despite Red Ed Microbrain.

[The Other John]

Post by Jeff Layman
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

My panels were installed in 2011 and the break even point was forecast to
be 7 years and it was exactly right. My F.I.T. income is higher than my
dual fuel outgoings.

[alan_m]

Post by The Other John

Post by Jeff Layman
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

My panels were installed in 2011 and the break even point was forecast to
be 7 years and it was exactly right. My F.I.T. income is higher than my
dual fuel outgoings.

The FIT payment scheme you are on is probably a lot more generous than
available to anyone installing solar today.

Money Saving Expert web page suggests for a £7k installation cost the
savings may be around £300 per annum.

https://www.moneysavingexpert.com/utilities/free-solar-panels/

This is for a small scale domestic installation and not for the
commercial installation this thread is about.

[RJH]

Post by alan_m

Post by The Other John

Post by Jeff Layman
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

My panels were installed in 2011 and the break even point was forecast to
be 7 years and it was exactly right. My F.I.T. income is higher than my
dual fuel outgoings.

The FIT payment scheme you are on is probably a lot more generous than
available to anyone installing solar today.
Money Saving Expert web page suggests for a £7k installation cost the
savings may be around £300 per annum.

If I cant increase the value of £7k bu at least £700 a year I have
bought the wrong financial instrument.

Plus, you'd need to discount the cash flow. So more than £700 in that example.

What does it cost to wash the birdshot off them?

Maintenance is another issue. As is a sinking fund to replace the inverter and
batteries, probably within 10 years.

All of this should have been factored in to a quote - which I think is pretty
routine.

In my case, 8 reasonably oriented panels and a 5kWh battery was about £7k,
with a predicted payback of about 10 years. After 6 months, the prediction
looks to be reasonably accurate. Time will tell.

Post by alan_m
https://www.moneysavingexpert.com/utilities/free-solar-panels/
This is for a small scale domestic installation and not for the
commercial installation this thread is about.

Since solar produces when all the other panels in the country are
producing it's pretty much worthless without subsidy.
It is questionable how much longer politicians will be able to justify
such an arrant waste of public money

Apart from no VAT, I didn't use any public money.

Another variable that I don't expect everyone else to share is the CO2 saved,
although I haven't calculated the net saving - if any. Plus I get a good
feeling from generating my own electricity, and not stuffing the pockets of
the energy companies. TBH I didn't pay very much attention to the payback when
I had them installed.

Your mileage undoubtedly varies.

[ajh]

Post by RJH
Maintenance is another issue. As is a sinking fund to replace the inverter and
batteries, probably within 10 years.

My inverter and panels show no loss in performance after 12 years so far.

Post by RJH
In my case, 8 reasonably oriented panels and a 5kWh battery was about £7k,
with a predicted payback of about 10 years. After 6 months, the prediction
looks to be reasonably accurate. Time will tell.

It is getting interesting; if I just consider the PV panels and
inverter we fitted 18 months ago to a house with a much better aspect
than mine it came to £7k, at current Octopus rates if the generation
were exported the return on the 5MWh/annum generated would be £750,
that's 10.71%, of course you never get to draw your capital out but what
the hell, I would never have spent the money.

In fact with an additional £4k for 10kWh battery and £1k for EV charger
it is looking better, the arbitrage on buying electricity to charge car
and battery and selling during the day looks like it is running the car
and house for free and covering standing charges for gas and
electricity. How long these rates will last is a bit of a guess and what
amortisation per kWh for storing in the battery is debatable but I'm
unlikely to outlive the battery.

Post by RJH
Apart from no VAT, I didn't use any public money.

That's right

Post by RJH
Another variable that I don't expect everyone else to share is the CO2 saved,
although I haven't calculated the net saving - if any. Plus I get a good
feeling from generating my own electricity, and not stuffing the pockets of
the energy companies. TBH I didn't pay very much attention to the payback when
I had them installed.

My way of thinking too so I have been pleasantly surprised with both
installations

[alan_m]

Post by alan_m
Money Saving Expert web page suggests for a £7k installation cost the
savings may be around £300 per annum.

If I cant increase the value of £7k bu at least £700 a year I have
bought the wrong financial instrument.
What does it cost to wash the birdshot off them?

Post by alan_m
https://www.moneysavingexpert.com/utilities/free-solar-panels/

Money Saving Expert does suggest not borrowing the £7k for installation
as the interest on the loan will wipe out the potential savings for many
years and make the payback much longer than ten to fifteen years.

Since solar produces when all the other panels in the country are
producing it's pretty much worthless without subsidy.
It is questionable how much longer politicians will be able to justify
such an arrant waste of public money

Soon with all this increase in other renewable energy payments for
feeding in from solar will be almost zero, except during a cold winter's
night :)

[AnthonyL]

On Thu, 12 Sep 2024 15:57:08 +0100, The Natural Philosopher

Post by alan_m

Post by The Other John

Post by Jeff Layman
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

My panels were installed in 2011 and the break even point was forecast to
be 7 years and it was exactly right.  My F.I.T. income is higher than my
dual fuel outgoings.

The FIT payment scheme you are on is probably a lot more generous than
available to anyone installing solar today.
Money Saving Expert web page suggests for a £7k installation cost the
savings may be around £300 per annum.

If I cant increase the value of £7k bu at least £700 a year I have
bought the wrong financial instrument.

Whilst I agree with your sentiments I really would like to know where
you have found a guaranteed 10% minimum return on capital.

[The Natural Philosopher]

Post by AnthonyL
On Thu, 12 Sep 2024 15:57:08 +0100, The Natural Philosopher

Post by alan_m

Post by The Other John

Post by Jeff Layman
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

My panels were installed in 2011 and the break even point was forecast to
be 7 years and it was exactly right.  My F.I.T. income is higher than my
dual fuel outgoings.

The FIT payment scheme you are on is probably a lot more generous than
available to anyone installing solar today.
Money Saving Expert web page suggests for a £7k installation cost the
savings may be around £300 per annum.

If I cant increase the value of £7k bu at least £700 a year I have
bought the wrong financial instrument.

Whilst I agree with your sentiments I really would like to know where
you have found a guaranteed 10% minimum return on capital.

Its very simple. Every six months or so I review a set of tradeable
funds I have investment in, and if they are doing less thabn 10% , I
sell them. I then look for any exchange tradeable funds that have
delivered more than 30% annually over the last three years and buy them..

The point is neither I, nor the fund managers I effectively employ, keep
their money in one place.

And some of them buy options and get even better returns in a rising market.

Its a lot less work than 'working' or installing solar panels

I probably make about £20,000 a year for about 4 hours work every 6 months

But you cant just leave the money there. Sectors go out of fashion. Tech
funds made a lot during Covid. Now energy funds are doing well.

And there exists another possibility.
Buy gold.

That's gone up 900% in the last 20 years. Dunno what the compound
equivalent rate is with that. Probably exactly the same as
inflation...they say a loaf of bread costs the same in gold as it did in
roman times...

If you stick your money in a deposit account, then the bank gambles at
the financial casino with it.

And inflation eats into it.

I'd rather trust a fund manager with a proven track record on 1%
commission to do that.

One that I can fire online in ten seconds

[Andrew]

Post by The Natural Philosopher

Post by AnthonyL
On Thu, 12 Sep 2024 15:57:08 +0100, The Natural Philosopher

Post by alan_m

Post by The Other John

Post by Jeff Layman
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

My panels were installed in 2011 and the break even point was forecast to
be 7 years and it was exactly right.  My F.I.T. income is higher than my
dual fuel outgoings.

The FIT payment scheme you are on is probably a lot more generous than
available to anyone installing solar today.
Money Saving Expert web page suggests for a £7k installation cost the
savings may be around £300 per annum.

If I cant increase the value of £7k bu at least £700 a year I have
bought the wrong financial instrument.

Whilst I agree with your sentiments I really would like to know where
you have found a guaranteed 10% minimum return on capital.

Its very simple. Every six months or so I review a set of tradeable
funds I have investment in, and if they are doing less thabn 10% , I
sell them. I then look for any exchange tradeable funds  that have
delivered more than 30% annually over the last three years and buy them..
The point is neither I, nor the fund managers I effectively employ, keep
their money in one place.
And some of them buy options and get even better returns in a rising market.
Its a lot less work than 'working' or installing solar panels
I probably make about £20,000 a year for about 4 hours work every 6 months
But you cant just leave the money there. Sectors go out of fashion. Tech
funds made a lot during Covid. Now energy funds are doing well.

And crashed badly in 2022, and again in August 2024.

Scottish Mortgage lost more than half its Nov 2021 value by May 2022.

Post by The Natural Philosopher
And there exists another possibility.
Buy gold.

Just about the worst thing you can do. Zero interest and storage
charges on top. Better to buy Black Rock funds.

Post by The Natural Philosopher
That's gone up 900%  in the last 20 years. Dunno what the compound
equivalent rate is with that. Probably exactly the same as
inflation...they say a loaf of bread costs the same in gold as it did in
roman times...

Only because Gordon Brown signalled his intention to sell the UK gold
stocks back in about 2002, whereupon all the fast movers like JP Morgan
short-sold gold and forced its price down to a historic low point and
then bought our gold at massive discount.

Post by The Natural Philosopher
If you stick your money in a deposit account, then the bank gambles at
the financial casino with it.

Any one who used Lettuce Monday to buy gilts will have locked in a 5%+
yield, and if held to redemption, would make a nice tax-free capital
gain too.

4% is still available, but the capital gains are much less than what
was available in October 2022 and July 2023.

Post by The Natural Philosopher
And inflation eats into it.
I'd rather trust a fund manager with a proven track record on 1%
commission to do that.
One that I can fire online in ten seconds

Your money may have underperformed for a while before you make
that decision.

[The Natural Philosopher]

Post by alan_m

Post by The Other John

Post by Jeff Layman
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

My panels were installed in 2011 and the break even point was forecast to
be 7 years and it was exactly right.  My F.I.T. income is higher than my
dual fuel outgoings.

The FIT payment scheme you are on is probably a lot more generous than
available to anyone installing solar today.
Money Saving Expert web page suggests for a £7k installation cost the
savings may be around £300 per annum.

If I cant increase the value of £7k bu at least £700 a year I have
bought the wrong financial instrument.
What does it cost to wash the birdshot off them?

Post by alan_m
https://www.moneysavingexpert.com/utilities/free-solar-panels/
This is for a small scale domestic installation and not for the
commercial installation this thread is about.

Since solar produces when all the other panels in the country are
producing it's pretty much worthless without subsidy.

It is questionable how much longer politicians will be able to justify
such an arrant waste of public money

[RJH]

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it would
be around twice that time.

Panels are very very cheap now. <£100 for a 500W panel, which would give> you
https://midsummerwholesale.co.uk/buy/longi-solar/himo6-hth-530
https://globalsolaratlas.info/detail?c=52.197585,0.139154,11&s=52.205016,0.129888&m=site&pv=small,180,38,1
On a domestic price cap tariff that would pay back in about 9 months, and
possibly less time on an uncapped business tariff.
What costs is the installation: inverter, fixings, access, labour.
Those are wildly different depending on your site - an industrial building
with a huge roof, existing roof access and simple fixings could be much
cheaper to install compared with a domestic property with only space for a
few panels, awkward tile mountings and a need for scaffolding.

Roof fixings on my slate pitched roof cost a fair chunk of my overall
installation - I'd guess about 15% of the £7000.

Something like that building with a lot of roof area sounds like a perfect
spot for cheap solar, and they have a giant building that's likely going to
consume the energy at any time of day, so it's straight money off their
bill.
No brainer.
Theo

Quite. I'm having difficulty understanding the antagonism towards it all.

[Theo]

Post by RJH

No brainer.

Quite. I'm having difficulty understanding the antagonism towards it all.

1) Should not be subsidised. All that subsidies do is hide the cost. Doesn't
make something cheaper in terms of the amount of society's resources used.

There are no solar subsidies available. This is purely a business decision.

https://www.fmb.org.uk/homepicks/solar-panels/solar-panel-grants/
make s you a lying piece ofgshit

Please indicate which of those schemes applies to the owners of a giant
stadium.

Anyhow, those are grants not subsidies. Subsidy pays you an ongoing return
as you do whatever thing you are being encouraged to do - generate solar
electricity in this case. The grants, as I stated in the paragraph you
snipped, give a one-off contribution towards the upfront cost - generally in
very limited circumstances (eg a homeowner on benefits).

I don't think you'll find any stadium claiming benefits, and the domestic
Feed In Tariff (a per-unit subsidy) has been dead for 5 years.

Theo

[Andrew]

Post by Theo

Post by RJH

No brainer.

Quite. I'm having difficulty understanding the antagonism towards it all.

1) Should not be subsidised. All that subsidies do is hide the cost. Doesn't
make something cheaper in terms of the amount of society's resources used.

There are no solar subsidies available. This is purely a business decision.

https://www.fmb.org.uk/homepicks/solar-panels/solar-panel-grants/
make s you a lying piece ofgshit

Please indicate which of those schemes applies to the owners of a giant
stadium.
Anyhow, those are grants not subsidies. Subsidy pays you an ongoing return
as you do whatever thing you are being encouraged to do - generate solar
electricity in this case. The grants, as I stated in the paragraph you
snipped, give a one-off contribution towards the upfront cost - generally in
very limited circumstances (eg a homeowner on benefits).
I don't think you'll find any stadium claiming benefits, and the domestic
Feed In Tariff (a per-unit subsidy) has been dead for 5 years.
Theo

Buy those FITs last 25 years and the earlier ones are RPI linked !.
This should never have been done, when most other things have shifted
to CPI linking.

[Theo]

Post by RJH

No brainer.

Quite. I'm having difficulty understanding the antagonism towards it all.

1) Should not be subsidised. All that subsidies do is hide the cost. Doesn't
make something cheaper in terms of the amount of society's resources used.

There are no solar subsidies available. This is purely a business decision.

Homeowners on low incomes may get some grants for better
heating/insulation/etc which in limited cases may include solar - that's not
a subsidy as such, it's just paying for improvements the householder
couldn't otherwise afford, like a new boiler.

2) FIT should be capped at what the customer pays per unit. Shouldn't be
making a profit at other customers' expense.

Current export tariffs pay less than the import tariffs.

The FIT hasn't been open for new installations since 2019. Folks who signed
up on a prior tariff get the terms they signed up for - that's how
investment works. They bought panels when they were much more expensive and
that's why the FIT subsidy was available - to make the payback time
reasonable.

ie all this antagonism is based on out of date arguments from the situation
a decade or more ago. The proponents don't seem to have noticed the world
has moved on.

We may well get a plug-in when it comes time to replace the car, and will then
look at getting some panels here to charge it up. I'm just hoping WW3 holds
off for long enough for that to be an astute investment.

The longer you wait the cheaper the panels become, although labour cost
inflation may wipe out the saving. That's a point in favour of DIY :-)

I'd really like the price of microinverters to come down, because that would
make for an easy DIY install. Unfortunately Enphase dominate the market and
prices seem static. There are a few new brands coming on the market which
look interesting, but they may not have G.98 approval for the UK:
https://www.cleanenergyreviews.info/microinverter-comparison

Theo

[The Natural Philosopher]

Post by RJH

No brainer.

Quite. I'm having difficulty understanding the antagonism towards it all.

1) Should not be subsidised. All that subsidies do is hide the cost. Doesn't
make something cheaper in terms of the amount of society's resources used.

There are no solar subsidies available. This is purely a business decision.

https://www.fmb.org.uk/homepicks/solar-panels/solar-panel-grants/

make s you a lying piece ofgshit

[alan_m]

Post by RJH
Roof fixings on my slate pitched roof cost a fair chunk of my overall
installation - I'd guess about 15% of the £7000.

Possibly another 6 to 7% on health and safety - the scaffolding required
to work at heights.


I note new regulation coming soon about the installation of associated
batteries. They will no longer be allowed in lofts and if internal to a
house the requrement to arrest the spread of fire.

[The Natural Philosopher]

Post by RJH

No brainer.
Theo

Quite. I'm having difficulty understanding the antagonism towards it all.

Because *I* have to pay for your virtue signalling and grifting.

Anyone with solar panels on their roof is a thieving grifter and a total
cunt, since its my money that pays them to keep them there.

[RJH]

Post by The Natural Philosopher

Post by RJH

No brainer.
Theo

Quite. I'm having difficulty understanding the antagonism towards it all.

Because *I* have to pay for your virtue signalling and grifting.

Who exactly have I swindled? Or virtue signalled?

Post by The Natural Philosopher
Anyone with solar panels on their roof is a thieving grifter and a total
cunt, since its my money that pays them to keep them there.

I genuinely don't understand. How does my installation, or any self-financed
system, disadvantage you?

[The Natural Philosopher]

Post by RJH
I genuinely don't understand. How does my installation, or any self-financed
system, disadvantage you?

The mere existence of intermittent flows on the grid increases system
costs for *everyone*

Your solar panels force some gas station to operate inefficiently
because when you are generating, overall demand diminishes, and at
sunset demand leaps up more than it otherwise would, so the gas station
has to be fired up from cold, incerasing emissions and costs.
Your solar panels force grid infrastructure to be built to deliver it
when you are not generating.
So the power companies are delivering less chargeable units for the same
grid overheads.

So electricity prices have to increase. For everyone *else*.

[RJH]

Post by The Natural Philosopher

Post by RJH
I genuinely don't understand. How does my installation, or any self-financed
system, disadvantage you?

Just noticed this reply . . .

Post by The Natural Philosopher
The mere existence of intermittent flows on the grid increases system
costs for *everyone*
Your solar panels force some gas station to operate inefficiently
because when you are generating, overall demand diminishes, and at
sunset demand leaps up more than it otherwise would, so the gas station
has to be fired up from cold, incerasing emissions and costs.

I wouldn't mind seeing the figures that support that, er, hypothesis. And it's
not just a switch, when the sun goes down, solar stops. Many systems have
batteries for example.

Post by The Natural Philosopher
Your solar panels force grid infrastructure to be built to deliver it
when you are not generating.

Of course. I don't see a problem with that.

Post by The Natural Philosopher
So the power companies are delivering less chargeable units for the same
grid overheads.
So electricity prices have to increase. For everyone *else*.

I export a fair chunk - about as much as I use - at less than I pay to import.
So there is some benefit to you lot, my pleasure etc.

Anyway, there's bound to be some transitional costs. You feel they're
unecessary or excessive because you don't appreciate the benefits.

[The Natural Philosopher]

Post by RJH

Post by The Natural Philosopher

Post by RJH
I genuinely don't understand. How does my installation, or any self-financed
system, disadvantage you?

Just noticed this reply . . .

Post by The Natural Philosopher
The mere existence of intermittent flows on the grid increases system
costs for *everyone*
Your solar panels force some gas station to operate inefficiently
because when you are generating, overall demand diminishes, and at
sunset demand leaps up more than it otherwise would, so the gas station
has to be fired up from cold, incerasing emissions and costs.

I wouldn't mind seeing the figures that support that, er, hypothesis. And it's
not just a switch, when the sun goes down, solar stops. Many systems have
batteries for example.

Nothing like enough.

All the batteries on teh grid might keep it up for a minute or two at
best...

Post by RJH

Post by The Natural Philosopher
Your solar panels force grid infrastructure to be built to deliver it
when you are not generating.

Of course. I don't see a problem with that.

That grids infrastructure costs money, and its the consumer that pays,.

Post by RJH

Post by The Natural Philosopher
So the power companies are delivering less chargeable units for the same
grid overheads.
So electricity prices have to increase. For everyone *else*.

I export a fair chunk - about as much as I use - at less than I pay to import.
So there is some benefit to you lot, my pleasure etc.

No there isn't.
Whaty you export is as expensive or more expensive than gas coal or nuclear
WE PAY

Post by RJH
Anyway, there's bound to be some transitional costs. You feel they're
unecessary or excessive because you don't appreciate the benefits.

There are no benefitrs. Only costs
--
If you tell a lie big enough and keep repeating it, people will
eventually come to believe it. The lie can be maintained only for such
time as the State can shield the people from the political, economic
and/or military consequences of the lie. It thus becomes vitally
important for the State to use all of its powers to repress dissent, for
the truth is the mortal enemy of the lie, and thus by extension, the
truth is the greatest enemy of the State.

Joseph Goebbels

[Theo]

Post by The Natural Philosopher

Post by RJH

Post by The Natural Philosopher

Post by RJH
I genuinely don't understand. How does my installation, or any self-financed
system, disadvantage you?

Just noticed this reply . . .

Post by The Natural Philosopher
The mere existence of intermittent flows on the grid increases system
costs for *everyone*
Your solar panels force some gas station to operate inefficiently
because when you are generating, overall demand diminishes, and at
sunset demand leaps up more than it otherwise would, so the gas station
has to be fired up from cold, incerasing emissions and costs.

I wouldn't mind seeing the figures that support that, er, hypothesis. And it's
not just a switch, when the sun goes down, solar stops. Many systems have
batteries for example.

Nothing like enough.
All the batteries on teh grid might keep it up for a minute or two at
best...

That's not the point. If I have solar and a home battery, the battery
allows me to gather up enough solar to keep me going during the evening and
hours of darkness. eg if my daily consumption is 13kWh and I have a 13kWh
battery, with enough solar panels I can generate that 13kWh during the day
and need take nothing from the grid.

I can make it to generate that 13kWh only in peak summer or in the depth of
winter - it just depends on how much I can/want to oversize the solar
system. Through-winter oversizing is probably not practical for most people
(they don't have enough roof) so it's just a case of how early/late in the
spring/autumn will be covered, versus how much to spend on hardware and how
much is practical in their particular property.

If you can handle the daily variations with local batteries, you don't need
to call on any peaker plants when everyone is cooking their tea in the
evening. You're then only importing from gas plants in the winter period when
the solar output is limited.

That avoids all the inefficiencies you state with warming up gas peaker
plants. And in the winter you can charge the battery up from the grid
when energy is cheapest to flatten out your demand, even when there's no
solar output.

Theo

[Spike]

Post by Theo

Post by The Natural Philosopher

Post by RJH

Post by The Natural Philosopher

Post by RJH
I genuinely don't understand. How does my installation, or any self-financed
system, disadvantage you?

Just noticed this reply . . .

Post by The Natural Philosopher
The mere existence of intermittent flows on the grid increases system
costs for *everyone*
Your solar panels force some gas station to operate inefficiently
because when you are generating, overall demand diminishes, and at
sunset demand leaps up more than it otherwise would, so the gas station
has to be fired up from cold, incerasing emissions and costs.

I wouldn't mind seeing the figures that support that, er, hypothesis. And it's
not just a switch, when the sun goes down, solar stops. Many systems have
batteries for example.

Nothing like enough.
All the batteries on teh grid might keep it up for a minute or two at
best...

That's not the point. If I have solar and a home battery, the battery
allows me to gather up enough solar to keep me going during the evening and
hours of darkness. eg if my daily consumption is 13kWh and I have a 13kWh
battery, with enough solar panels I can generate that 13kWh during the day
and need take nothing from the grid.
I can make it to generate that 13kWh only in peak summer or in the depth of
winter - it just depends on how much I can/want to oversize the solar
system. Through-winter oversizing is probably not practical for most people
(they don't have enough roof) so it's just a case of how early/late in the
spring/autumn will be covered, versus how much to spend on hardware and how
much is practical in their particular property.
If you can handle the daily variations with local batteries, you don't need
to call on any peaker plants when everyone is cooking their tea in the
evening. You're then only importing from gas plants in the winter period when
the solar output is limited.
That avoids all the inefficiencies you state with warming up gas peaker
plants. And in the winter you can charge the battery up from the grid
when energy is cheapest to flatten out your demand, even when there's no
solar output.

I’m not sure your last point is fully valid.

The winter before last had three separate periods of about ten days to two
weeks each, where gas was supplying about 10 to 12GW more than the reliably
unreliable renewables.

‘Battery storage is the answer!’ cried the unthinking and innumerate
greenies.

But it would not have been the answer, because there simply wasn’t enough
energy available to recharge the batteries before the next winter blocking
high kicked in.

‘More batteries!’ cry the greenies, without realising they have now got
*four* backups for their free sources of energy, three huge battery farms
and CCGT. In any other world this would put such people in a loony bin.

10GW of energy gap for (say) ten days is 2.4TWh. How large an area would a
battery farm of that capability cover? How much would it cost?

[Theo]

Post by Spike

Post by Theo
That avoids all the inefficiencies you state with warming up gas peaker
plants. And in the winter you can charge the battery up from the grid
when energy is cheapest to flatten out your demand, even when there's no
solar output.

I’m not sure your last point is fully valid.
The winter before last had three separate periods of about ten days to two
weeks each, where gas was supplying about 10 to 12GW more than the reliably
unreliable renewables.
‘Battery storage is the answer!’ cried the unthinking and innumerate
greenies.
But it would not have been the answer, because there simply wasn’t enough
energy available to recharge the batteries before the next winter blocking
high kicked in.
‘More batteries!’ cry the greenies, without realising they have now got
*four* backups for their free sources of energy, three huge battery farms
and CCGT. In any other world this would put such people in a loony bin.
10GW of energy gap for (say) ten days is 2.4TWh. How large an area would a
battery farm of that capability cover? How much would it cost?

We were discussing home batteries, not grid scale ones.

Even if the grid is 100% gas, there are still peaks and troughs. People
cook their tea at 6pm but they don't cook very much at 3am. So charging the
home battery at 3am and discharging it at 6pm saves having to run an extra gas
peaker at 6pm.

The same would happen if the grid was 100% nuclear - you really really don't
want peaker nuclear plants, so it's better to spread the load out using home
batteries than it is to build extra nukes.

In practice, there's often spare renewable energy (not necessarily 3am, but
whenever the front passes over) so the more kWh you can get from that the
less kWh of gas you have to burn.

Yes you still have to build the gas plants but you don't run them 24/7, you
just run them in weeks when you need them and so only pay for the fuel when
you need to burn it. As we have already been doing with coal plants.

Theo

[Spike]

Post by Theo

Post by Spike

Post by Theo
That avoids all the inefficiencies you state with warming up gas peaker
plants. And in the winter you can charge the battery up from the grid
when energy is cheapest to flatten out your demand, even when there's no
solar output.

I’m not sure your last point is fully valid.
The winter before last had three separate periods of about ten days to two
weeks each, where gas was supplying about 10 to 12GW more than the reliably
unreliable renewables.
‘Battery storage is the answer!’ cried the unthinking and innumerate
greenies.
But it would not have been the answer, because there simply wasn’t enough
energy available to recharge the batteries before the next winter blocking
high kicked in.
‘More batteries!’ cry the greenies, without realising they have now got
*four* backups for their free sources of energy, three huge battery farms
and CCGT. In any other world this would put such people in a loony bin.
10GW of energy gap for (say) ten days is 2.4TWh. How large an area would a
battery farm of that capability cover? How much would it cost?

We were discussing home batteries, not grid scale ones.
Even if the grid is 100% gas, there are still peaks and troughs. People
cook their tea at 6pm but they don't cook very much at 3am. So charging the
home battery at 3am and discharging it at 6pm saves having to run an extra gas
peaker at 6pm.
The same would happen if the grid was 100% nuclear - you really really don't
want peaker nuclear plants, so it's better to spread the load out using home
batteries than it is to build extra nukes.

You don’t need ‘peaker’ nuclear plants, you use any surplus electricity to
e.g desalinate water, pump water up hills, generate hydrogen for some
strange reason, or flog it to becalmed Denmark.

Post by Theo
In practice, there's often spare renewable energy (not necessarily 3am, but
whenever the front passes over) so the more kWh you can get from that the
less kWh of gas you have to burn.
Yes you still have to build the gas plants but you don't run them 24/7, you
just run them in weeks when you need them and so only pay for the fuel when
you need to burn it. As we have already been doing with coal plants.

Using real-world data, I did to death gas as a backup for the reliably
unreliable renewables earlier in the thread, in the grounds that it would
be more efficient not to build renewables in the first place.

The Irish Republic did a study of their gas and renewables, and similarly
discovered it was more efficient to run their CCGTs flat out, while
exporting the renewables to the energy-short UK, presumably at inflated
prices.

There was a wind turbine fire locally a few weeks ago, the fire crews were
there quickly, but had to stand around idle until the owner finally turned
up and isolated it. By which time it was just a charred ruin. Having a
battery in every loft is a seriously ungood idea.

[Tim+]

Post by Spike
There was a wind turbine fire locally a few weeks ago, the fire crews were
there quickly, but had to stand around idle until the owner finally turned
up and isolated it. By which time it was just a charred ruin. Having a
battery in every loft is a seriously ungood idea.

Wind turbines don’t have batteries hence a wind turbine fire has NO
relevance to domestic batteries. So why try and make a connection?

Lithium Iron phosphate batteries are probably lower risk than many domestic
electrical appliances.

Tim

[Spike]

Post by Tim+

Post by Spike
There was a wind turbine fire locally a few weeks ago, the fire crews were
there quickly, but had to stand around idle until the owner finally turned
up and isolated it. By which time it was just a charred ruin. Having a
battery in every loft is a seriously ungood idea.

Wind turbines don’t have batteries hence a wind turbine fire has NO
relevance to domestic batteries. So why try and make a connection?

The connection, which you seem to be unaware of, is the procedure used by
Fire Brigades when dealing with electricity generation, such as standing
about watching the conflagration while waiting for someone to make it
electrically safe to squirt water on.

Water…electricity…bad mix…

Post by Tim+
Lithium Iron phosphate batteries are probably lower risk than many domestic
electrical appliances.

[Tim Streater]

Post by Spike

Post by Tim+

Post by Spike
There was a wind turbine fire locally a few weeks ago, the fire crews were
there quickly, but had to stand around idle until the owner finally turned
up and isolated it. By which time it was just a charred ruin. Having a
battery in every loft is a seriously ungood idea.

Wind turbines don’t have batteries hence a wind turbine fire has NO
relevance to domestic batteries. So why try and make a connection?

The connection, which you seem to be unaware of, is the procedure used by
Fire Brigades when dealing with electricity generation, such as standing
about watching the conflagration while waiting for someone to make it
electrically safe to squirt water on.

The salient point, then, being that if the householder says there's a battery
in the loft, the FB will just twiddle their thumbs as your house burns down?

[charles]

Post by Tim Streater

Post by Spike

Post by Spike
There was a wind turbine fire locally a few weeks ago, the fire crews
were there quickly, but had to stand around idle until the owner
finally turned up and isolated it. By which time it was just a
charred ruin. Having a battery in every loft is a seriously ungood
idea.

Wind turbines don‘t have batteries hence a wind turbine fire has NO
relevance to domestic batteries. So why try and make a connection?

The connection, which you seem to be unaware of, is the procedure used
by Fire Brigades when dealing with electricity generation, such as
standing about watching the conflagration while waiting for someone to
make it electrically safe to squirt water on.

The salient point, then, being that if the householder says there's a
battery in the loft, the FB will just twiddle their thumbs as your house
burns down?

Unlikely. My battery would only provide 51v - far less than mains voltage
and they don't expect that to be turned off. Turbines will have avery much
higher voltage output and be coupled to a simialr high voltage line.

Post by Tim Streater
--

[alan_m]

Post by charles
Unlikely. My battery would only provide 51v - far less than mains voltage
and they don't expect that to be turned off. Turbines will have avery much
higher voltage output and be coupled to a simialr high voltage line.

It's not the voltage that is the problem but the energy stored in the
battery.

What happens if the battery is shorted?

Also 50 volts can be lethal.

[The Natural Philosopher]

Post by alan_m

Post by charles
Unlikely. My battery would only provide 51v - far less than mains voltage
and they don't expect that to be turned off. Turbines  will have avery
much
higher voltage output and be coupled to a simialr high voltage line.

It's not the voltage that is the problem but the energy stored in the
battery.
What happens if the battery is shorted?
Also 50 volts can be lethal.

NOt to a human

[Spike]

Post by Tim Streater

Post by Spike

Post by Tim+

Post by Spike
There was a wind turbine fire locally a few weeks ago, the fire crews were
there quickly, but had to stand around idle until the owner finally turned
up and isolated it. By which time it was just a charred ruin. Having a
battery in every loft is a seriously ungood idea.

Wind turbines don’t have batteries hence a wind turbine fire has NO
relevance to domestic batteries. So why try and make a connection?

The connection, which you seem to be unaware of, is the procedure used by
Fire Brigades when dealing with electricity generation, such as standing
about watching the conflagration while waiting for someone to make it
electrically safe to squirt water on.

The salient point, then, being that if the householder says there's a battery
in the loft, the FB will just twiddle their thumbs as your house burns down?

What they used to do was wait while a specialist officer also drove to the
scene of the fire to assess the risk to the crews, so it’s much as you
suggest.

In the case of solar panels they now squirt black goo over them to stop
them generating.

[alan_m]

Post by Tim Streater
The salient point, then, being that if the householder says there's a battery
in the loft, the FB will just twiddle their thumbs as your house burns down?

I believe new regulations* state that batteries for solar etc. cannot be
fitted in a domestic property loft, and when fitted within house they
may/will have to be within a fire containing enclosure. Fitted in a
garage is probably OK. Some aspects of battery fitting may now come
under building regulations as well as electrical regulations.

Fitting batteries under the stairs may not be a sensible option :)

*I believe proposed regulations that are likely to be adopted soon.

[charles]

Post by alan_m

Post by Tim Streater
The salient point, then, being that if the householder says there's a
battery in the loft, the FB will just twiddle their thumbs as your
house burns down?

I believe new regulations* state that batteries for solar etc. cannot be
fitted in a domestic property loft, and when fitted within house they
may/will have to be within a fire containing enclosure. Fitted in a
garage is probably OK. Some aspects of battery fitting may now come
under building regulations as well as electrical regulations.

According to the manufacturer's data, the battery I have weighs 110Kg. Not
the easiest thing to get in to a loft. Mine is mounted on an outside wall
of the house -at ground level.

Post by alan_m
Fitting batteries under the stairs may not be a sensible option :)
*I believe proposed regulations that are likely to be adopted soon.

[Theo]

Post by alan_m

Post by Tim Streater
The salient point, then, being that if the householder says there's a battery
in the loft, the FB will just twiddle their thumbs as your house burns down?

I believe new regulations* state that batteries for solar etc. cannot be
fitted in a domestic property loft, and when fitted within house they
may/will have to be within a fire containing enclosure. Fitted in a
garage is probably OK. Some aspects of battery fitting may now come
under building regulations as well as electrical regulations.

It's a terrible idea to put batteries in a loft anyway - lofts cook and
freeze, both of which are unkind to batteries. Unless you've insulated
behind the tiles so the loft is a conditioned space, then it's just another
part of the house.

Theo

[Tim Streater]

Post by Theo

Post by alan_m

Post by Tim Streater
The salient point, then, being that if the householder says there's a battery
in the loft, the FB will just twiddle their thumbs as your house burns down?

I believe new regulations* state that batteries for solar etc. cannot be
fitted in a domestic property loft, and when fitted within house they
may/will have to be within a fire containing enclosure. Fitted in a
garage is probably OK. Some aspects of battery fitting may now come
under building regulations as well as electrical regulations.

It's a terrible idea to put batteries in a loft anyway - lofts cook and
freeze, both of which are unkind to batteries. Unless you've insulated
behind the tiles so the loft is a conditioned space, then it's just another
part of the house.

Ah, interesting. That would imply that a garage separate from the house would
also be poor/bad location.

[Paul]

Post by Tim Streater

Post by Theo

Post by alan_m

Post by Tim Streater
The salient point, then, being that if the householder says there's a battery
in the loft, the FB will just twiddle their thumbs as your house burns down?

I believe new regulations* state that batteries for solar etc. cannot be
fitted in a domestic property loft, and when fitted within house they
may/will have to be within a fire containing enclosure. Fitted in a
garage is probably OK. Some aspects of battery fitting may now come
under building regulations as well as electrical regulations.

It's a terrible idea to put batteries in a loft anyway - lofts cook and
freeze, both of which are unkind to batteries. Unless you've insulated
behind the tiles so the loft is a conditioned space, then it's just another
part of the house.

Ah, interesting. That would imply that a garage separate from the house would
also be poor/bad location.

A good location, is underground, below the frost line.
If you've ever gone caving, you know what that temperature is :-)
Perfect for batteries. The only issue, is holes in the ground tend to
flood, so your payload would need to be waterproof.

Garages aren't that nice. The temperature swing is quite large.
I would prefer a car port to a garage, for parking a BEV.
And that's what I've got, is a car port. The car port idea,
cuts off the temperature peaking issue a bit. For a BEV though,
the disadvantage would be charging the thing when the air temperature
is rather low. It would require battery conditioning, and increase
the electricity used.

Paul

[Tim Streater]

Post by Paul

Post by Tim Streater

Post by Theo

Post by alan_m

Post by Tim Streater
The salient point, then, being that if the householder says there's a battery
in the loft, the FB will just twiddle their thumbs as your house burns down?

I believe new regulations* state that batteries for solar etc. cannot be
fitted in a domestic property loft, and when fitted within house they
may/will have to be within a fire containing enclosure. Fitted in a
garage is probably OK. Some aspects of battery fitting may now come
under building regulations as well as electrical regulations.

It's a terrible idea to put batteries in a loft anyway - lofts cook and
freeze, both of which are unkind to batteries. Unless you've insulated
behind the tiles so the loft is a conditioned space, then it's just another
part of the house.

Ah, interesting. That would imply that a garage separate from the house would
also be poor/bad location.

A good location, is underground, below the frost line.
If you've ever gone caving, you know what that temperature is :-)

Hah, there is no chance of that ever happening. The heat death of the Universe
will occur sooner.

Post by Paul
Perfect for batteries. The only issue, is holes in the ground tend to
flood, so your payload would need to be waterproof.
Garages aren't that nice. The temperature swing is quite large.
I would prefer a car port to a garage, for parking a BEV.

Well we have a car port, but its openness is what gave the scroats who burgled
us the idea that we were out So we added garage doors and now it's a garage.

[Andy Burns]

Post by alan_m
I believe new regulations* state that batteries for solar etc. cannot be
fitted in a domestic property loft, and when fitted within house they
may/will have to be within a fire containing enclosure. Fitted in a
garage is probably OK.  Some aspects of battery fitting may now come
under building regulations as well as electrical regulations.
Fitting batteries under the stairs may not be a sensible option :)
*I believe proposed regulations that are likely to be adopted soon.

From BSI PAS 63100:2024 (it's a free download, but they do want your
inside leg measurement.


6.5.5 Batteries shall not be installed in any of the following locations:

a) rooms in which persons are intended to sleep;

b) routes used as a means of escape that are not defined as protected
escape routes, including landings, staircases and corridors;

c) corridors, shafts, stairs or lobbies of protected escape routes;

d) firefighting lobbies, shafts or staircases;

e) storage cupboards, enclosures or spaces opening into rooms in which
persons are intended to sleep;

f) outdoors (ground-mounted or wall-mounted in a suitable enclosure)
within 1m of:
1) escape routes;
2) doors;
3) windows; or
4) ventilation ports.

g) voids, roof spaces or lofts;

h) within 2m of stored flammable materials and fuel storage tanks or
cylinders; and

i) cellars or basements that have no access to the outside of the building.

[RJH]

<div id="editor" contenteditable="false">> *I believe proposed regulations
that are likely to be adopted soon.
From BSI PAS 63100:2024 (it's a free download, but they do want your
inside leg measurement.

snip

i) cellars or basements that have no access to the outside of the building.

Does that mean *direct* access - so, a door from the basement into the garden
for example? Or access to outside via other rooms - door into hallway etc?

Or both, to avoid installation in a sealed-off space?

[alan_m]

Post by Andy Burns

Post by alan_m
I believe new regulations* state that batteries for solar etc. cannot
be fitted in a domestic property loft, and when fitted within house
they may/will have to be within a fire containing enclosure. Fitted in
a garage is probably OK.  Some aspects of battery fitting may now come
under building regulations as well as electrical regulations.
Fitting batteries under the stairs may not be a sensible option :)
*I believe proposed regulations that are likely to be adopted soon.

From BSI PAS 63100:2024 (it's a free download, but they do want your
inside leg measurement.
a) rooms in which persons are intended to sleep;
b) routes used as a means of escape that are not defined as protected
escape routes, including landings, staircases and corridors;
c) corridors, shafts, stairs or lobbies of protected escape routes;
d) firefighting lobbies, shafts or staircases;
e) storage cupboards, enclosures or spaces opening into rooms in which
persons are intended to sleep;
f) outdoors (ground-mounted or wall-mounted in a suitable enclosure)
   1) escape routes;
   2) doors;
   3) windows; or
   4) ventilation ports.
g) voids, roof spaces or lofts;
h) within 2m of stored flammable materials and fuel storage tanks or
cylinders; and
i) cellars or basements that have no access to the outside of the building.

Given that list in my house any batteries would have to be ground
mounted in the garden and if protection from rain and freezing
conditions is required in a purpose built enclosure.

Possibly many terrace houses around my way would be the same. I and
friends of mine were commenting on a estate of £1million+ houses that
have been packed in like sardines on a smallish plot of land. Possibly
not easy to find areas for banks of batteries.





mailto : news {at} admac {dot} myzen {dot} co {dot} uk

[charles]

Post by alan_m

Post by Andy Burns

Post by alan_m
I believe new regulations* state that batteries for solar etc. cannot
be fitted in a domestic property loft, and when fitted within house
they may/will have to be within a fire containing enclosure. Fitted in
a garage is probably OK. Some aspects of battery fitting may now
come under building regulations as well as electrical regulations.
Fitting batteries under the stairs may not be a sensible option :)
*I believe proposed regulations that are likely to be adopted soon.

From BSI PAS 63100:2024 (it's a free download, but they do want your
inside leg measurement.
a) rooms in which persons are intended to sleep;
b) routes used as a means of escape that are not defined as protected
escape routes, including landings, staircases and corridors;
c) corridors, shafts, stairs or lobbies of protected escape routes;
d) firefighting lobbies, shafts or staircases;
e) storage cupboards, enclosures or spaces opening into rooms in which
persons are intended to sleep;
f) outdoors (ground-mounted or wall-mounted in a suitable enclosure)
within 1m of: 1) escape routes; 2) doors; 3) windows; or 4)
ventilation ports.
g) voids, roof spaces or lofts;
h) within 2m of stored flammable materials and fuel storage tanks or
cylinders; and
i) cellars or basements that have no access to the outside of the building.

Given that list in my house any batteries would have to be ground
mounted in the garden and if protection from rain and freezing
conditions is required in a purpose built enclosure.

Mine was provided with a canopy to keep direct rainfall off it and the
higher mounted inverter.. I suspect the enclosure itself is water tight.
The label says IP65!

[Tim Streater]

Post by RJH

Post by The Natural Philosopher
Your solar panels force grid infrastructure to be built to deliver it
when you are not generating.

Of course. I don't see a problem with that.

This increases costs. It means the grid is bigger than it need be. Just like
those who advocate a tidal barrier (such as in the Bristol Channel). When it's
pointed out that 4 times a day, this produces no powwer, they just say - well,
build another in anti-phase.

My riposte to that is to point out that you've just built two power stations
in order to get the output of one, which is a waste of society's resources. A
bit like the Soviets - they were unable to build reliable kit (e.g. planes) so
they just built many more than needed and kept some as spares. Of course if
the books are a state secret, then it's easy to cook them

Which is also why continental railways sometimes seem cheap - subsidised and
the accounts are not your business, chum.

[RJH]

Post by Tim Streater

Post by RJH

Post by The Natural Philosopher
Your solar panels force grid infrastructure to be built to deliver it
when you are not generating.

Of course. I don't see a problem with that.

This increases costs. It means the grid is bigger than it need be. Just like
those who advocate a tidal barrier (such as in the Bristol Channel). When it's
pointed out that 4 times a day, this produces no powwer, they just say - well,
build another in anti-phase.
My riposte to that is to point out that you've just built two power stations
in order to get the output of one, which is a waste of society's resources. A
bit like the Soviets - they were unable to build reliable kit (e.g. planes) so
they just built many more than needed and kept some as spares. Of course if
the books are a state secret, then it's easy to cook them

It's not a waste if you consider the wider benefits. For example,
environmental, and socio-economic (help with fuel poverty say). I obviously
accept that you and others don't buy that argument, but we can both agree that
it's there.

I'd guess there's some crude economic benefit to not producing any more
carbon-intensive or nuclear energy generation - would a solar/wind array be
cheaper in capital and revenue terms at actual (not SMR-imagined) prices?

It just seems staggering to me - watching the vast sums of money being pumped
into not actually producing any nuclear power at all. Just scoping and getting
rid of waste.

Post by Tim Streater
Which is also why continental railways sometimes seem cheap - subsidised and
the accounts are not your business, chum.

They might also be cheap because they're properly maintained, relaible,
popular, don't need to make any profit, and don't rely on massive government
subsidies to keep shareholders happy.

[Andy Burns]

Post by RJH

Post by Tim Streater
Which is also why continental railways sometimes seem cheap - subsidised

They might also be cheap because they're properly maintained, relaible,
popular, don't need to make any profit, and don't rely on massive government
subsidies to keep shareholders happy.

Now we have track ownership re-nationalised and train operating
companies heading the same way, presumably subsidies can go away and
journey costs be directly reflected in ticket prices?

[Tim Streater]

Post by RJH

Post by Tim Streater

Post by RJH

Post by The Natural Philosopher
Your solar panels force grid infrastructure to be built to deliver it
when you are not generating.

Of course. I don't see a problem with that.

This increases costs. It means the grid is bigger than it need be. Just like
those who advocate a tidal barrier (such as in the Bristol Channel). When it's
pointed out that 4 times a day, this produces no powwer, they just say - well,
build another in anti-phase.
My riposte to that is to point out that you've just built two power stations
in order to get the output of one, which is a waste of society's resources. A
bit like the Soviets - they were unable to build reliable kit (e.g. planes) so
they just built many more than needed and kept some as spares. Of course if
the books are a state secret, then it's easy to cook them

It's not a waste if you consider the wider benefits. For example,
environmental, and socio-economic (help with fuel poverty say). I obviously
accept that you and others don't buy that argument, but we can both agree that
it's there.

Building two power stations where one will do seems to me to be an un-benefit.

Post by RJH
I'd guess there's some crude economic benefit to not producing any more
carbon-intensive or nuclear energy generation - would a solar/wind array be
cheaper in capital and revenue terms at actual (not SMR-imagined) prices?

The solar/wind array will need backup, in particular for the winter periods of
high pressure when there's no wind anywhere. Solar produces zero under these
conditions. Now, what are you going to use for backup? Oh dear, another
situation where we build two sources of power to get the output of one. Why
not just build the nuclear in the first place. SMRs, in particular. And the
nuclear stations last rather longer than wind farms, especially off-shore
ones.

Post by RJH
It just seems staggering to me - watching the vast sums of money being pumped
into not actually producing any nuclear power at all. Just scoping and getting
rid of waste.

Scoping is hardly the fault of the nuclear industry. It's due to the lies
spread by greenies which cause ordinary people to panic over nothing.

Waste is a solved problem and has been for years.

Post by RJH

Post by Tim Streater
Which is also why continental railways sometimes seem cheap - subsidised and
the accounts are not your business, chum.

They might also be cheap because they're properly maintained, relaible,
popular, don't need to make any profit, and don't rely on massive government
subsidies to keep shareholders happy.

Something that doesn't need to make a profit, as you put it, can be relied
upon to be inefficient. And prices are set low because of subsidies with no
oversight.

[The Natural Philosopher]

Post by RJH
would a solar/wind array be
cheaper in capital and revenue terms at actual (not SMR-imagined) prices?

Not if you included all the other crap you need to make a 'renewable'
grid work reliably,

And its the renewable shills who are in fantasy land. Not the nuclear
power contingent

[Spike]

Post by RJH

Post by Tim Streater

Post by RJH

Post by The Natural Philosopher
Your solar panels force grid infrastructure to be built to deliver it
when you are not generating.

Of course. I don't see a problem with that.

This increases costs. It means the grid is bigger than it need be. Just like
those who advocate a tidal barrier (such as in the Bristol Channel). When it's
pointed out that 4 times a day, this produces no powwer, they just say - well,
build another in anti-phase.
My riposte to that is to point out that you've just built two power stations
in order to get the output of one, which is a waste of society's resources. A
bit like the Soviets - they were unable to build reliable kit (e.g. planes) so
they just built many more than needed and kept some as spares. Of course if
the books are a state secret, then it's easy to cook them

It's not a waste if you consider the wider benefits. For example,
environmental, and socio-economic (help with fuel poverty say). I obviously
accept that you and others don't buy that argument, but we can both agree that
it's there.
I'd guess there's some crude economic benefit to not producing any more
carbon-intensive or nuclear energy generation - would a solar/wind array be
cheaper in capital and revenue terms at actual (not SMR-imagined) prices?

The combined-cycle gas turbine (CCGT) uses ‘waste’ heat from the turbine to
provide steam pressure to run a second generator, thus improving the
overall efficiency of the system.

During fire-up the turbines are very inefficient, from ~0% for the first 5
minutes, to 25% to about 45 minutes, when the second part of the
combined-cycle kicks in at about 60% efficiency.

With 60% efficiency, each GW of power output uses 1/0.6=1.67GW of gas.

Interestingly, if a 1GW CCGT was replaced by a 1GW wind farm, real-world
data suggests the latter, over a year, would produce an average of 0.36GW,
leaving 0.64GW to be supplied by the CCGT now operating in an intermittent
regime of stop/start and throttled-back running in which it might be only
40% efficient.

So over the year the CCGT will use 0.64/0.4=1.6GW of gas, which is the same
as if it ran in efficient mode and the wind farm didn’t exist, the latter
having cost money and materials to no real effect.

Renewables are a waste of resources.

Greens are nuts.

[RJH]

Post by RJH

No brainer.

Quite. I'm having difficulty understanding the antagonism towards it all.

1) Should not be subsidised. All that subsidies do is hide the cost. Doesn't
make something cheaper in terms of the amount of society's resources used.

What subsidies? The ones available to low income households? My (Limited)
understanding of such subsidies is that there's very low take-up, and it's for
'light' solar only - no battery for example.

And do you see no benefit for such households - only costs?

2) FIT should be capped at what the customer pays per unit. Shouldn't be
making a profit at other customers' expense.

I agree broadly with the principle of profit. Are there many of those original
highly advantageous FIT recipients about?

We may well get a plug-in when it comes time to replace the car, and will then
look at getting some panels here to charge it up. I'm just hoping WW3 holds
off for long enough for that to be an astute investment.

Ah. So you're antagonistic because it doesn't suit you. Yet. Got it.

[Tim Streater]

Post by RJH

Post by RJH

No brainer.

Quite. I'm having difficulty understanding the antagonism towards it all.

1) Should not be subsidised. All that subsidies do is hide the cost. Doesn't
make something cheaper in terms of the amount of society's resources used.

What subsidies? The ones available to low income households? My (Limited)
understanding of such subsidies is that there's very low take-up, and it's for
'light' solar only - no battery for example.
And do you see no benefit for such households - only costs?

2) FIT should be capped at what the customer pays per unit. Shouldn't be
making a profit at other customers' expense.

I agree broadly with the principle of profit. Are there many of those original
highly advantageous FIT recipients about?

We may well get a plug-in when it comes time to replace the car, and will then
look at getting some panels here to charge it up. I'm just hoping WW3 holds
off for long enough for that to be an astute investment.

Ah. So you're antagonistic because it doesn't suit you. Yet. Got it.

<raspberry>

I'm antagonistic for the reasons given, which may well no longer apply.
However, what we see in the media and also from MilliBean is that all his new
solar investments will solve our energy production problems and "power
thousands of households". Statements of this nature tend to mislead people.

We're on the end of a rural 11kV, so a small system here, with battery, ought
to be able to cover the short outages we get here, too.

[Vir Campestris]

Post by Tim Streater
We're on the end of a rural 11kV, so a small system here, with battery, ought
to be able to cover the short outages we get here, too.

AIUI domestic inverters are not allowed to run "islanded" - without any
external feed.

Andy

[charles]

Post by Vir Campestris

Post by Tim Streater
We're on the end of a rural 11kV, so a small system here, with battery,
ought to be able to cover the short outages we get here, too.

AIUI domestic inverters are not allowed to run "islanded" - without any
external feed.

Mine does - and did for a sort time in the summer. Mind you, the switch
is "break before make"

[The Natural Philosopher]

Post by Vir Campestris

Post by Tim Streater
We're on the end of a rural 11kV, so a small system here, with battery, ought
to be able to cover the short outages we get here, too.

AIUI domestic inverters are not allowed to run "islanded" - without any
external feed.
Andy

Course they are.

Switch off the dead incoming volts and switch over to your wown
--
If you tell a lie big enough and keep repeating it, people will
eventually come to believe it. The lie can be maintained only for such
time as the State can shield the people from the political, economic
and/or military consequences of the lie. It thus becomes vitally
important for the State to use all of its powers to repress dissent, for
the truth is the mortal enemy of the lie, and thus by extension, the
truth is the greatest enemy of the State.

Joseph Goebbels

[The Other John]

Post by The Natural Philosopher
Switch off the dead incoming volts and switch over to your wown

If the mains dies my inverter shuts down so it can't shock anyone fixing
the supply.

[charles]

Post by The Other John

Post by The Natural Philosopher
Switch off the dead incoming volts and switch over to your wown

If the mains dies my inverter shuts down so it can't shock anyone fixing
the supply.

It should be isolated.

[The Other John]

Post by charles
It should be isolated.

There is an isolator switch for servicing the inverter or panels but the
inverter shuts itself down if the mains dies.

[charles]

Post by The Other John

Post by charles
It should be isolated.

There is an isolator switch for servicing the inverter or panels but the
inverter shuts itself down if the mains dies.

I'm not quite clear about what your inverter does if it only works when
there is mains.

[Tim+]

Post by charles

Post by The Other John

Post by charles
It should be isolated.

There is an isolator switch for servicing the inverter or panels but the
inverter shuts itself down if the mains dies.

I'm not quite clear about what your inverter does if it only works when
there is mains.

Converts solar DC to mains voltage AC.

Tim

[The Other John]

Post by charles
I'm not quite clear about what your inverter does if it only works when
there is mains.

It feeds our house and the neighbours in parallel with the grid.
Presumably for power to flow outwards the voltage must be higher than the
mains.

[Fredxx]

On 10/10/2024 15:34, The Other John wrote:

<snip>

Post by The Other John
Presumably for power to flow outwards the voltage must be higher than the
mains.

<Pedantic mode>

That's not strictly true. If the output voltage is lower that the supply
then the generator/inverter power factor lags, if higher higher then it
leads.

https://www.dieselgeneratortech.com/generators/what-is-power-factor-lagging-and-lead-of-generator-set.html

What applies to 3-phase also applies to a single phase.

</Pedantic mode>

[The Natural Philosopher]

Post by The Other John

Post by charles
I'm not quite clear about what your inverter does if it only works when
there is mains.

It feeds our house and the neighbours in parallel with the grid.
Presumably for power to flow outwards the voltage must be higher than the
mains.

Technically slightly phase advanced to the mains

which is why it needs the mains to work

[The Other John]

Post by The Natural Philosopher
Technically slightly phase advanced to the mains
which is why it needs the mains to work

Oh I see. Now I understand. Thanks.

[Fredxx]

Post by The Other John

Post by The Natural Philosopher
Technically slightly phase advanced to the mains
which is why it needs the mains to work

Oh I see. Now I understand. Thanks.

As per usual TNP has got everything wrong.

There are are hybrid inverters that have the ability to keep providing
power while isolating the power from the grid. You will obviously have
to install batteries to have power if the panels don't produce enough.

https://diysolarforum.com/threads/off-grid-backup-power-using-hybrid-inverters.46783/

For safety and cost these are rarely fitted.

There doesn't need to be a phase difference. If the inverter is acting
as if over-excited then the current will lead, if under-excited the
current will lag.

[Theo]

Post by Fredxx

Post by The Other John

Post by The Natural Philosopher
Technically slightly phase advanced to the mains
which is why it needs the mains to work

Oh I see. Now I understand. Thanks.

As per usual TNP has got everything wrong.
There are are hybrid inverters that have the ability to keep providing
power while isolating the power from the grid. You will obviously have
to install batteries to have power if the panels don't produce enough.
https://diysolarforum.com/threads/off-grid-backup-power-using-hybrid-inverters.46783/
For safety and cost these are rarely fitted.

Some battery inverters have two outputs: one for the regular grid
connection, and one emergency output when the power fails. The grid
connection is also used for sensing the grid and grid battery charging.

How you wire that is up to you, but typically you'd have a transfer switch
selecting one or other and feeding your CU. The inverter's mains
input/output is always connected to the mains. When the mains is powered,
the CU is fed from the mains. When there's a power cut, the transfer switch
changes over to power the CU from the emergency output. The point of the
transfer switch is it takes time to switch over so that it never connects
both mains and emergency terminals together.

Post by Fredxx
There doesn't need to be a phase difference. If the inverter is acting
as if over-excited then the current will lead, if under-excited the
current will lag.

By over-excited I think you mean the voltage is higher, ie if Vout > Vmains
then you'll push current into the grid, if Vout < Vmains you'll draw from
the grid? All in phase?

Theo

[The Natural Philosopher]

Post by The Other John

Post by charles
It should be isolated.

There is an isolator switch for servicing the inverter or panels but the
inverter shuts itself down if the mains dies.

Well that's not my fault. I didnt design it

[The Other John]

Post by The Natural Philosopher
Well that's not my fault. I didnt design it

I never said you did. Cheer up, I'm (usually) on your side! :)

[Andy Burns]

Post by The Other John

Post by The Natural Philosopher
Switch off the dead incoming volts and switch over to your wown

If the mains dies my inverter shuts down so it can't shock anyone fixing
the supply.

You haven't mentioned whether you have battery storage? Unless you do,
there's not much point in your house power staying on, only to go off
when the next cloud rolls past. Hybrid inverters can isolate from the
grid and carry-on (with reduced output).

[The Other John]

Post by Andy Burns
You haven't mentioned whether you have battery storage? Unless you do,
there's not much point in your house power staying on, only to go off
when the next cloud rolls past. Hybrid inverters can isolate from the
grid and carry-on (with reduced output).

I don't have a battery.

[alan_m]

Post by RJH
What subsidies? The ones available to low income households? My (Limited)
understanding of such subsidies is that there's very low take-up, and it's for
'light' solar only - no battery for example.

In the past solar has been taken up by those who can afford the initial
outlay (with the subsidised discount) and have benefitted from generous
FIT payments.

As there is no magic money tree it seems to come as a suprise to some
that the money for all these subsidies came from the (mainly)
undisclosed green tax on all our utility bills.

Solar hasn't helped low income households but the exact opposite. The
well off have had the disposable cash to invest in solar, albeit made
cheaper with subsidies, and the poor (and the rest of us) have had to
pay for it with higher utility bills.

The same appears to be happening with heat pumps for domestic central
heating. However, in my opinion, there is also a problem with the
mis-selling or mis-advertising of ASHP when the changes to the rest of
the heating system are ignored. A lot of fly by night companies selling
ASHP suggest a ASHP is just a simple swap out for a gas/oil/LPG boiler.
They are more interested in getting their hands on the grants rather
than doing decent job.

[Tim Streater]

Post by alan_m

Post by RJH
What subsidies? The ones available to low income households? My (Limited)
understanding of such subsidies is that there's very low take-up, and it's for
'light' solar only - no battery for example.

In the past solar has been taken up by those who can afford the initial
outlay (with the subsidised discount) and have benefitted from generous
FIT payments.
As there is no magic money tree it seems to come as a suprise to some
that the money for all these subsidies came from the (mainly)
undisclosed green tax on all our utility bills.
Solar hasn't helped low income households but the exact opposite. The
well off have had the disposable cash to invest in solar, albeit made
cheaper with subsidies, and the poor (and the rest of us) have had to
pay for it with higher utility bills.

Precisely the points I was trying to make.

[Tim Streater]

Post by RJH

No brainer.

Quite. I'm having difficulty understanding the antagonism towards it all.

1) Should not be subsidised. All that subsidies do is hide the cost. Doesn't
make something cheaper in terms of the amount of society's resources used.

2) FIT should be capped at what the customer pays per unit. Shouldn't be
making a profit at other customers' expense.

We may well get a plug-in when it comes time to replace the car, and will then
look at getting some panels here to charge it up. I'm just hoping WW3 holds
off for long enough for that to be an astute investment.

[Theo]

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it would
be around twice that time.

Panels are very very cheap now. <£100 for a 500W panel, which would give
https://midsummerwholesale.co.uk/buy/longi-solar/himo6-hth-530
https://globalsolaratlas.info/detail?c=52.197585,0.139154,11&s=52.205016,0.129888&m=site&pv=small,180,38,1
On a domestic price cap tariff that would pay back in about 9 months, and
possibly less time on an uncapped business tariff.

Even the (domestic housing) solar panel installation companies hyping up
the payback period are quoting at least 8 years.

That's because the cost of panels is trivial compared with the scaffolding
to get on the roof. Let's say you're having a 4kWp setup - that's £800 for
the panels, but it'll be ~£1k for the scaffolding alone. Meanwhile this
stadium is fitting 1000 panels (cost ~£100k) and probably doesn't need any
scaffolding because there's already roof stairs.

Also it's probably a steel roof so maybe you can use simple screw on clamps
and an existing electrical riser, while a domestic tile roof needs tiles
removing and cutting, brackets fitting, rails installing, wires running, all
for a poxy 8 panels.

I'm not sure what kind of inverter they'll use on a 500kWp setup, but it
probably costs proportionately less than 125 domestic inverters.

On a domestic installation the positioning of the fixed panels is not
optimal on the majority of houses. Most households will not use all of
the output during the long days in the summer, even with additional
batteries, and will not achieve a feed in anywhere near the domestic
price cap tariff.

Domestic can be marginal unless you have some of:
a) cheap roof access
b) cheap fixings
c) a good use for the electricity (either regular daytime loads or an EV)

If you can achieve those you can get good payback times, but the solar
cowboys are not cutting those costs (all more profit for them).

Theo

[alan_m]

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it would
be around twice that time.
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

One of the Utilita Energy commercial business models is to fund the
installation up front and provide the maintenance costs for the first 5
years. These costs form a loan which must be paid back over a 5 year
period. The company paying back this loan "owns" the generated
electricity. Any electricity that is not locally used is exported at a
fixed price set by Utilita Energy. As one of the Utilita Energy web
pages indicates - there will only be savings in the first 5 years if the
value of the electricity used and the value of the export is greater
than the repayments on the loan (and presumably the interest on that loan).

Their other business model is to fund all installation and ongoing
maintenance but they "own" all the electricity generated for 30 years.
This electricity is sold back at a undisclosed discount to the company
where the panels are located.

I assume that if a return on the investment is going to be AFTER (not
during) 5 years they have entered a contract for the former scheme.
Extrapolating from scant case study figures Utilita Energy have
published for a smaller installation the yearly loan repayments may be
close to £250k/annum

[RJH]

Post by alan_m

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it would
be around twice that time.
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

One of the Utilita Energy commercial business models is to fund the
installation up front and provide the maintenance costs for the first 5
years. These costs form a loan which must be paid back over a 5 year
period. The company paying back this loan "owns" the generated
electricity. Any electricity that is not locally used is exported at a
fixed price set by Utilita Energy. As one of the Utilita Energy web
pages indicates - there will only be savings in the first 5 years if the
value of the electricity used and the value of the export is greater
than the repayments on the loan (and presumably the interest on that loan).
Their other business model is to fund all installation and ongoing
maintenance but they "own" all the electricity generated for 30 years.
This electricity is sold back at a undisclosed discount to the company
where the panels are located.
I assume that if a return on the investment is going to be AFTER (not
during) 5 years they have entered a contract for the former scheme.
Extrapolating from scant case study figures Utilita Energy have
published for a smaller installation the yearly loan repayments may be
close to £250k/annum

I've read a couple of nightmare anecdotes where comapanies like this make a
real hash of the roof - simply drilling through tiles or smashing them to fix
the brackets.

[Theo]

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it would
be around twice that time.

Panels are very very cheap now. <£100 for a 500W panel, which would give
you back about 500kWh pa with optimal positioning:
https://midsummerwholesale.co.uk/buy/longi-solar/himo6-hth-530
https://globalsolaratlas.info/detail?c=52.197585,0.139154,11&s=52.205016,0.129888&m=site&pv=small,180,38,1

On a domestic price cap tariff that would pay back in about 9 months, and
possibly less time on an uncapped business tariff.

What costs is the installation: inverter, fixings, access, labour.
Those are wildly different depending on your site - an industrial building
with a huge roof, existing roof access and simple fixings could be much
cheaper to install compared with a domestic property with only space for a
few panels, awkward tile mountings and a need for scaffolding.

Something like that building with a lot of roof area sounds like a perfect
spot for cheap solar, and they have a giant building that's likely going to
consume the energy at any time of day, so it's straight money off their
bill.

No brainer.

Theo

[alan_m]

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it would
be around twice that time.

Panels are very very cheap now. <£100 for a 500W panel, which would give
https://midsummerwholesale.co.uk/buy/longi-solar/himo6-hth-530
https://globalsolaratlas.info/detail?c=52.197585,0.139154,11&s=52.205016,0.129888&m=site&pv=small,180,38,1
On a domestic price cap tariff that would pay back in about 9 months, and
possibly less time on an uncapped business tariff.

Even the (domestic housing) solar panel installation companies hyping up
the payback period are quoting at least 8 years.

On a domestic installation the positioning of the fixed panels is not
optimal on the majority of houses. Most households will not use all of
the output during the long days in the summer, even with additional
batteries, and will not achieve a feed in anywhere near the domestic
price cap tariff.

[Tim+]

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it would
be around twice that time.

Panels are very very cheap now. <£100 for a 500W panel, which would give
https://midsummerwholesale.co.uk/buy/longi-solar/himo6-hth-530
https://globalsolaratlas.info/detail?c=52.197585,0.139154,11&s=52.205016,0.129888&m=site&pv=small,180,38,1
On a domestic price cap tariff that would pay back in about 9 months, and
possibly less time on an uncapped business tariff.

Even the (domestic housing) solar panel installation companies hyping up
the payback period are quoting at least 8 years.
On a domestic installation the positioning of the fixed panels is not
optimal on the majority of houses. Most households will not use all of
the output during the long days in the summer, even with additional
batteries, and will not achieve a feed in anywhere near the domestic
price cap tariff.

Combine it with a battery and you can run on off peak prices and export at
double that price.

TIM

[www.GymRats.uk]

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it would
be around twice that time.
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

My 4.6 kWp panels were installed end of 2015 and cost just under £7500.
Factoring the FIT payments and 100% usage of everything produced, it
broke even in June 2021 and as of end July (2024) it's returned a profit
of £6200.
No electricity is "wasted" on unnecessary stuff done for the sake of
trying to use excess energy, it's all used on regular day-to-day usage,
same as having a large 100% efficient battery but without having a
battery!

[Chris J Dixon]

Post by www.GymRats.uk
My 4.6 kWp panels were installed end of 2015 and cost just under £7500.
Factoring the FIT payments and 100% usage of everything produced, it
broke even in June 2021 and as of end July (2024) it's returned a profit
of £6200.
No electricity is "wasted" on unnecessary stuff done for the sake of
trying to use excess energy, it's all used on regular day-to-day usage,
same as having a large 100% efficient battery but without having a
battery!

Just to be clear, are you saying that you manage not to actually
export any energy at all?

Chris

[www.GymRatZ.co.uk]

Post by Chris J Dixon

Post by www.GymRats.uk
My 4.6 kWp panels were installed end of 2015 and cost just under £7500.
Factoring the FIT payments and 100% usage of everything produced, it
broke even in June 2021 and as of end July (2024) it's returned a profit
of £6200.
No electricity is "wasted" on unnecessary stuff done for the sake of
trying to use excess energy, it's all used on regular day-to-day usage,
same as having a large 100% efficient battery but without having a
battery!

Just to be clear, are you saying that you manage not to actually
export any energy at all?

I do export everything un-used to all the neighbours in the area and
then they give it back as and when my demand exceeds production.
The very reason I'll never have a smart meter, my mechanical meter
doesn't have a backstop. Don't know what year they started fitting them
but the date on my meter says 1984.

Not "electricity theft" as I'm paying the going rate for every kWh used
in excess of that which I am supplying.

Far more fair than the trillions of government contracts handed out to
"chums" for backhanders and bonuses.

[Tim+]

Post by www.GymRatZ.co.uk

Post by Chris J Dixon

Post by www.GymRats.uk
My 4.6 kWp panels were installed end of 2015 and cost just under £7500.
Factoring the FIT payments and 100% usage of everything produced, it
broke even in June 2021 and as of end July (2024) it's returned a profit
of £6200.
No electricity is "wasted" on unnecessary stuff done for the sake of
trying to use excess energy, it's all used on regular day-to-day usage,
same as having a large 100% efficient battery but without having a
battery!

Just to be clear, are you saying that you manage not to actually
export any energy at all?

I do export everything un-used to all the neighbours in the area and
then they give it back as and when my demand exceeds production.
The very reason I'll never have a smart meter, my mechanical meter
doesn't have a backstop. Don't know what year they started fitting them
but the date on my meter says 1984.
Not "electricity theft" as I'm paying the going rate for every kWh used
in excess of that which I am supplying.
Far more fair than the trillions of government contracts handed out to
"chums" for backhanders and bonuses.

Legally I believe your installer is supposed to inform the DNO about such
meters (and have them replaced) but I’m not sure that there’s any legal
imperative on householders to identify the problem and inform their power
company.

Definitely a case where it pays to keep shtoom and feign ignorance. ;-)

Tim

[www.GymRats.uk]

Post by Tim+
Legally I believe your installer is supposed to inform the DNO about such
meters (and have them replaced) but I’m not sure that there’s any legal
imperative on householders to identify the problem and inform their power
company.
Definitely a case where it pays to keep shtoom and feign ignorance. ;-)

There was a "moment" shortly after the installation when I wanted to see
if I could run a bigger inverter and put up to 20A rather than be
restricted to 16A just to prevent "clipping" in peak summer.

DNO visited to take a look and I made the excuse that I had to open the
garage from the inside for access as all the floors were up in the
house... Quickly plugged in a 3Kw I.R. heater and put the washing
machine on so when he was given access to the meter it was going in the
right direction.
Only way he'd let me exceed 16 Amps was to have 3-phase installed, so we
left it as it was and I kept the happy-meter. It extends my "summer" by
about a month as the summer build-up is consumed.
;¬)

[Spike]

Post by www.GymRats.uk
My 4.6 kWp panels were installed end of 2015 and cost just under £7500.
Factoring the FIT payments and 100% usage of everything produced, it
broke even in June 2021 and as of end July (2024) it's returned a profit
of £6200.
No electricity is "wasted" on unnecessary stuff done for the sake of
trying to use excess energy, it's all used on regular day-to-day usage,
same as having a large 100% efficient battery but without having a
battery!

JAAMOI, if the FIT payments were not factored in, what would the payback
time have been, and what profit would you have made?

These might be useful figures for anyone thinking of installing such panels
now that subsidies have ended.

[Theo]

Post by Spike

Post by www.GymRats.uk
My 4.6 kWp panels were installed end of 2015 and cost just under £7500.
Factoring the FIT payments and 100% usage of everything produced, it
broke even in June 2021 and as of end July (2024) it's returned a profit
of £6200.
No electricity is "wasted" on unnecessary stuff done for the sake of
trying to use excess energy, it's all used on regular day-to-day usage,
same as having a large 100% efficient battery but without having a
battery!

JAAMOI, if the FIT payments were not factored in, what would the payback
time have been, and what profit would you have made?
These might be useful figures for anyone thinking of installing such panels
now that subsidies have ended.

Not really, because the costs of materials and the costs of energy have
changed massively.

When I did this calculation for the wiki 2 years ago:
https://wiki.diyfaq.org.uk/index.php/Solar_PV_example:_single_garage

energy was 35p/unit, now it's 25p/unit, while in 2018 I took out a fixed
tariff at 10.35p/unit. Those 400W panels I priced up at £180/panel are now
£60/panel.

So you have to do the numbers based on your costs *now* and your projection of
the price of energy in the future.

"Past performance is no guarantee of future results", as they say.

Theo

[www.GymRatZ.co.uk]

Post by Theo
Not really, because the costs of materials and the costs of energy have
changed massively.
https://wiki.diyfaq.org.uk/index.php/Solar_PV_example:_single_garage
energy was 35p/unit, now it's 25p/unit, while in 2018 I took out a fixed
tariff at 10.35p/unit. Those 400W panels I priced up at £180/panel are now
£60/panel.
So you have to do the numbers based on your costs *now* and your projection of
the price of energy in the future.

I also wonder with the ever declining price of panels and presumably
inverters, what the average lifespan of current products is.

All mine would take would be a failed inverter and cost of replacement
would significantly reduce the R.O.I.

[Theo]

Post by www.GymRatZ.co.uk
I also wonder with the ever declining price of panels and presumably
inverters, what the average lifespan of current products is.
All mine would take would be a failed inverter and cost of replacement
would significantly reduce the R.O.I.

An inverter is a few hundred quid:
https://midsummerwholesale.co.uk/buy/Growatt-inverters

and swapping a failed one is an hour or so for an electrician. Unless
you've put it somewhere really awkward that requires scaffolding to get to,
it should be simple to access in a loft/garage/etc.

The panels are rated to last 25-30 years (with a few percent decrease in
output over that time) - I'd budget having to change inverter once or twice
in that time. But it's not a big cost overall.

Theo

[Theo]

Post by Theo
The panels are rated to last 25-30 years (with a few percent decrease in
output over that time) - I'd budget having to change inverter once or twice
in that time. But it's not a big cost overall.

Quick worked example:

Suppose you have a 4kWp system.
Peak generation in midsummer is about 500W per kWp (in the UK midlands at
optimal southerly orientation):
https://globalsolaratlas.info/detail?c=50.916887,0.510408,7&s=51.781436,-0.823553&m=site&pv=small,180,38,1
So you need a 2kW inverter.
A 2kW Growatt inverter is £137.20+VAT:
https://midsummerwholesale.co.uk/buy/Growatt-inverters/growatt-mic2000tl-x-afci

For every kWp you have you generate about 1MWh.
Every MWh you generate 'earns' or 'saves' you from £100 (at 10p/kWh) to £300
(at 30p/kWh).
Let's be pessimistic and say it's £100 per year per MWh of generation.
You generate 4MWh per year from your 4kWp panels, so that's £400.

That inverter is going to cost you £165 inc VAT (which you may not need to
pay, but we're being pessimistic).
Let's add £100 labour for installation, total £265.

So your inverter replacement is paid back within 8 months, on a pessimistic
estimate.

Theo

[Chris J Dixon]

Post by Theo
Suppose you have a 4kWp system.
Peak generation in midsummer is about 500W per kWp (in the UK midlands at
https://globalsolaratlas.info/detail?c=50.916887,0.510408,7&s=51.781436,-0.823553&m=site&pv=small,180,38,1
So you need a 2kW inverter.
https://midsummerwholesale.co.uk/buy/Growatt-inverters/growatt-mic2000tl-x-afci

If I read your reference accurately, I believe it is giving the
_average_ peak generation.

My 3.64 kWp installation gives a peak output of around 3.5 kW, so
a smaller inverter would be wasting some of my output.

Chris

[alan_m]

Post by Chris J Dixon

Post by Theo
Suppose you have a 4kWp system.
Peak generation in midsummer is about 500W per kWp (in the UK midlands at
https://globalsolaratlas.info/detail?c=50.916887,0.510408,7&s=51.781436,-0.823553&m=site&pv=small,180,38,1
So you need a 2kW inverter.
https://midsummerwholesale.co.uk/buy/Growatt-inverters/growatt-mic2000tl-x-afci

If I read your reference accurately, I believe it is giving the
_average_ peak generation.
My 3.64 kWp installation gives a peak output of around 3.5 kW, so
a smaller inverter would be wasting some of my output.

Isn't the 3.64kWp figure for a panel installed under ideal conditions
where the panel is at the equator, the sun is directly overhead at
mid-day in a cloudless sky AND the panel operating at 25C?

Even if it was a figure for the UK it is unlikely that a roof where
panels are installed are ideally aligned and the peak output would only
occur for a vanishly small period of time during the year.

The kWp is a figure that can be used to compare the output of panel A
with panel B.

You may want an inverter that can handle more that a panel can
realistically output as a factor of safety such as the extremes of
temperatures encountered where the inverter is installed.

[Chris J Dixon]

Post by alan_m

Post by Chris J Dixon

Post by Theo
Suppose you have a 4kWp system.
Peak generation in midsummer is about 500W per kWp (in the UK midlands at
https://globalsolaratlas.info/detail?c=50.916887,0.510408,7&s=51.781436,-0.823553&m=site&pv=small,180,38,1
So you need a 2kW inverter.
https://midsummerwholesale.co.uk/buy/Growatt-inverters/growatt-mic2000tl-x-afci

If I read your reference accurately, I believe it is giving the
_average_ peak generation.
My 3.64 kWp installation gives a peak output of around 3.5 kW, so
a smaller inverter would be wasting some of my output.

Isn't the 3.64kWp figure for a panel installed under ideal conditions
where the panel is at the equator, the sun is directly overhead at
mid-day in a cloudless sky AND the panel operating at 25C?

Taking the OP's figures, would suggest an inverter for my system
rated at 1820 kW.

My data is based on logs from my system. From a histogram of
actual output, I am able to see the peak of the 3.5 kW I already
quoted. From that same data I can see that around 15% of the time
it is generating it exceeds 1800 kW.

Chris

[charles]

Post by Theo

Post by www.GymRatZ.co.uk
I also wonder with the ever declining price of panels and presumably
inverters, what the average lifespan of current products is.
All mine would take would be a failed inverter and cost of replacement
would significantly reduce the R.O.I.

https://midsummerwholesale.co.uk/buy/Growatt-inverters
and swapping a failed one is an hour or so for an electrician. Unless
you've put it somewhere really awkward that requires scaffolding to get
to, it should be simple to access in a loft/garage/etc.

Ideally you have one inverter per panel. That then probably puts them on
the roof.

Post by Theo
The panels are rated to last 25-30 years (with a few percent decrease in
output over that time) - I'd budget having to change inverter once or
twice in that time. But it's not a big cost overall.
Theo

[RJH]

Post by Theo

Post by www.GymRatZ.co.uk
I also wonder with the ever declining price of panels and presumably
inverters, what the average lifespan of current products is.
All mine would take would be a failed inverter and cost of replacement
would significantly reduce the R.O.I.

https://midsummerwholesale.co.uk/buy/Growatt-inverters

have to say I didn't give it much thought, but the one I had installed was a
lot more than that (£1000+):

https://www.solartradesales.co.uk/givenergy-hybrid-3-6kw-inverter

Post by Theo
and swapping a failed one is an hour or so for an electrician. Unless
you've put it somewhere really awkward that requires scaffolding to get to,
it should be simple to access in a loft/garage/etc.
The panels are rated to last 25-30 years (with a few percent decrease in
output over that time) - I'd budget having to change inverter once or twice
in that time. But it's not a big cost overall.
Theo

[Andy Burns]

Post by RJH

Post by Theo
https://midsummerwholesale.co.uk/buy/Growatt-inverters

have to say I didn't give it much thought, but the one I had installed was a
https://www.solartradesales.co.uk/givenergy-hybrid-3-6kw-inverter

Yours is a hybrid, which can handle battery storage.

[Andy Burns]

Post by www.GymRats.uk
My 4.6 kWp panels were installed end of 2015 and cost just under £7500.
Factoring the FIT payments and 100% usage of everything produced, it
broke even in June 2021 and as of end July (2024) it's returned a profit
of £6200.

And you never send us all christmas cards ...

[www.GymRatZ.co.uk]

Post by Andy Burns

Post by www.GymRats.uk
My 4.6 kWp panels were installed end of 2015 and cost just under £7500.
Factoring the FIT payments and 100% usage of everything produced, it
broke even in June 2021 and as of end July (2024) it's returned a profit
of £6200.

And you never send us all christmas cards ...

I do, every year, a card to everyone not in my PLONK filter.... about 6
of you that'd be.
Perhaps Royal Mail subcontraced card delivery to Evri... I expect your
neighbours had it or it's still behind a bush in the garden.

;¬)

[alan_m]

Post by www.GymRatZ.co.uk

Post by Andy Burns

Post by www.GymRats.uk
My 4.6 kWp panels were installed end of 2015 and cost just under £7500.
Factoring the FIT payments and 100% usage of everything produced, it
broke even in June 2021 and as of end July (2024) it's returned a profit
of £6200.

And you never send us all christmas cards ...

I do, every year, a card to everyone not in my PLONK filter.... about 6
of you that'd be.
Perhaps Royal Mail subcontraced card delivery to Evri... I expect your
neighbours had it or it's still behind a bush in the garden.

The RM posting time to have a card delivered by Christmas is longer this
year. To guarantee delivery for Christmas the card has to be posted
before the 1st November.

[jon]

Post by alan_m

Post by www.GymRatZ.co.uk

Post by Andy Burns

Post by www.GymRats.uk
My 4.6 kWp panels were installed end of 2015 and cost just under £7500.
Factoring the FIT payments and 100% usage of everything produced, it
broke even in June 2021 and as of end July (2024) it's returned a
profit of £6200.

And you never send us all christmas cards ...

I do, every year, a card to everyone not in my PLONK filter.... about 6
of you that'd be.
Perhaps Royal Mail subcontraced card delivery to Evri... I expect your
neighbours had it or it's still behind a bush in the garden.

The RM posting time to have a card delivered by Christmas is longer this
year. To guarantee delivery for Christmas the card has to be posted
before the 1st November.

Don't bother with posting cards now, everyone of significance is dead.

[The Natural Philosopher]

Post by Jeff Layman
<https://www.bbc.co.uk/news/articles/cz07krz2z42o>
During a local radio broadcast a spokesman for Utilita said that they
expected the return on investment to take less than 5 years, as due to
the size of the installation the fixed costs were substantially less
than smaller installations. I was a bit surprised as I thought it
would be around twice that time.
I haven't been able to find any figures, but there are quite a few in
this NG who have a lot more expertise in these matters than me, and
should be better placed to comment.

I had a 6 kW system installed in July last year. No batteries.
Yielded 6.25 MWh in the first 12 months. Earned £695 flogging the
surplus back to Octopus (at 15p/unit)

Market rate for gas power is about 5p a unit.

'Saved' £306 in electricity I

didn't need to import.
So, a Grand in a year. System cost 7k, so a 7 year payback