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Solar PV Supplier Midlands?
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alan_m
2021-09-09 09:16:40 UTC
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Looking for a reputable and good value PV installer for a few properties i have id like to install PV on.
Any recomendations?
Ta Steve
Are solar panels now economically viable with reduced/no FIT subsidy?
What now is the typical payback/break even period, assuming that
electricity prices may be 2x higher in 5 years time.
--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk
The Natural Philosopher
2021-09-09 09:35:39 UTC
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Post by alan_m
Looking for a reputable and good value PV installer for a few
properties i have id like to install PV on.
Any recomendations?
Ta Steve
Are solar panels now economically viable with reduced/no FIT subsidy?
Almost certainly not
Post by alan_m
What now is the typical payback/break even period, assuming that
electricity prices may be 2x higher in 5 years time.
P
Probably longer than the panel lifetime
Although we are now seeing the effect of subsidised renewables driving
energy prices off the scale,.
--
Canada is all right really, though not for the whole weekend.

"Saki"
alan_m
2021-09-09 09:46:27 UTC
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Post by The Natural Philosopher
Although we are now seeing the effect of subsidised renewables driving
energy prices off the scale,.
Surely not with all the "free energy" from the sun and wind. ;) :)
--
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The Natural Philosopher
2021-09-09 09:49:31 UTC
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Post by alan_m
Post by The Natural Philosopher
Although we are now seeing the effect of subsidised renewables driving
energy prices off the scale,.
Surely not with all the "free energy" from the sun and wind. ;) :)
Well coal is free energy from the sun too
--
The biggest threat to humanity comes from socialism, which has utterly
diverted our attention away from what really matters to our existential
survival, to indulging in navel gazing and faux moral investigations
into what the world ought to be, whilst we fail utterly to deal with
what it actually is.
Tim Streater
2021-09-09 12:21:03 UTC
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Post by The Natural Philosopher
Post by alan_m
Post by The Natural Philosopher
Although we are now seeing the effect of subsidised renewables driving
energy prices off the scale,.
Surely not with all the "free energy" from the sun and wind. ;) :)
Well coal is free energy from the sun too
So is oil, come to that.
--
"Freedom is sloppy. But since tyranny's the only guaranteed byproduct of those who insist on a perfect world, freedom will have to do." -- Bigby Wolf
Theo
2021-09-09 14:54:32 UTC
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Post by alan_m
Looking for a reputable and good value PV installer for a few properties i have id like to install PV on.
Any recomendations?
Ta Steve
Are solar panels now economically viable with reduced/no FIT subsidy?
What now is the typical payback/break even period, assuming that
electricity prices may be 2x higher in 5 years time.
Let's run some numbers:

330W panel: £111.80 (Jinko)
3kW inverter: £310.70 (Growatt)

So let's say you could buy parts for a 10 panel system for ~£1.5K+VAT.
(prices from Midsummer Wholesale who aren't super cheap, but just have an
easy website)

That's not including the mounting system, which could vary quite a lot
depending on what you have, access requirements etc. If the roof is
partially shaded you might need optimisers too (about £35/shaded panel)

And then there's all the sundries - consumer unit, isolator, cables, etc
which will depend on your setup. Maybe another £200-300.

Perhaps total £2200 + mounting + labour. And that would get you
3648kWh/year on a south facing unshaded London roof, and if it displaces
usage on a current tariff of 20p/kWh it would pay back the parts bill in 3
years. Less so if you need to include a battery to timeshift usage.

So it really comes down to your mounting solution: if it's going to involve
complicated scaffolding and roof mounting systems, that's going to bump the
cost. If you're replacing the roof anyway, or is an easy DIY job
(outbuilding or something), it would seem a no-brainer.

Theo
alan_m
2021-09-09 16:45:25 UTC
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Post by Theo
Post by alan_m
Looking for a reputable and good value PV installer for a few properties i have id like to install PV on.
Any recomendations?
Ta Steve
Are solar panels now economically viable with reduced/no FIT subsidy?
What now is the typical payback/break even period, assuming that
electricity prices may be 2x higher in 5 years time.
330W panel: £111.80 (Jinko)
3kW inverter: £310.70 (Growatt)
So let's say you could buy parts for a 10 panel system for ~£1.5K+VAT.
(prices from Midsummer Wholesale who aren't super cheap, but just have an
easy website)
That's not including the mounting system, which could vary quite a lot
depending on what you have, access requirements etc. If the roof is
partially shaded you might need optimisers too (about £35/shaded panel)
And then there's all the sundries - consumer unit, isolator, cables, etc
which will depend on your setup. Maybe another £200-300.
Perhaps total £2200 + mounting + labour. And that would get you
3648kWh/year on a south facing unshaded London roof, and if it displaces
usage on a current tariff of 20p/kWh it would pay back the parts bill in 3
years. Less so if you need to include a battery to timeshift usage.
So it really comes down to your mounting solution: if it's going to involve
complicated scaffolding and roof mounting systems, that's going to bump the
cost. If you're replacing the roof anyway, or is an easy DIY job
(outbuilding or something), it would seem a no-brainer.
Theo
Government figures for May 2021 suggest around £1.6 to £1.7K per kW
(peak) installed. Say, £5.5K for your 3.3kW (peak) installation
https://www.gov.uk/government/statistics/solar-pv-cost-data

Other sources give a typical annual output from 3.3kW panels at around
3000 kWh from an ideal south facing installation.

3000kWh @ 20p per kWh = £600 (per annum)

so payback under 100% ideal conditions is more like 9 years.

If the panels are not ideally sited the payback will be longer.

Solar produces least when you need the energy most - during a cold
winters night. If the use of gas/oil is going to be discouraged for
heating then solar will will have a diminishing part of reducing annual
household bills.
--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk
Andy Burns
2021-09-10 13:56:47 UTC
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Post by Theo
330W panel: £111.80 (Jinko)
3kW inverter: £310.70 (Growatt)
So let's say you could buy parts for a 10 panel system for ~£1.5K+VAT > Perhaps total £2200 + mounting + labour.
But that's not going to get you a grid-tied system (approved installers
only for Smart Export scheme, and I bet they want to supply the kit at
higher prices) so would not be easy to use the output ... fridge freezer
and immersion heater?
Steve Walker
2021-09-10 16:59:40 UTC
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Post by Andy Burns
Post by Theo
330W panel: £111.80 (Jinko)
3kW inverter: £310.70 (Growatt)
So let's say you could buy parts for a 10 panel system for ~£1.5K+VAT
Post by Theo
Perhaps total £2200 + mounting + labour.
But that's not going to get you a grid-tied system (approved installers
only for Smart Export scheme, and I bet they want to supply the kit at
higher prices) so would not be easy to use the output ... fridge freezer
and immersion heater?
Which is part of the rip-off. I can see the need for approved installers
to install the connection from the approved control/switching device to
the mains supply, but the rest of the installation could be installed by
anyone and checked over or even a plug-together system, requiring no
checking.

All government schemes seem to come with "approved supplier/installer"
lists, where any grants are completely cancelled by higher prices than
everyone else.

One example from years ago was when I looked at converting my car to
LPG. There was a government grant available. All the installers on their
grant approved list were higher in price than the independents by
exactly the value of the grant! Considering that all installers were
required to be trained and licenced anyway, what good reason was there
for approving only a subset of installers?
Andy Burns
2021-09-10 17:57:22 UTC
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Post by Steve Walker
All government schemes seem to come with "approved supplier/installer"
lists, where any grants are completely cancelled by higher prices than
everyone else.
A lot of the PV installer websites are shy about their prices, wanting
you to fill in a form with contact details and they'll get back to you,
but this one at least gives sample packages

<https://www.genationalinfo.com/packages>

9x 340W panels plus a 3kW inverter fitted from £3,780
if you want a "massive" 4.8kWh battery that's another £3,240
Theo
2021-09-10 20:10:10 UTC
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Post by Steve Walker
Post by Andy Burns
But that's not going to get you a grid-tied system (approved installers
only for Smart Export scheme, and I bet they want to supply the kit at
higher prices) so would not be easy to use the output ... fridge freezer
and immersion heater?
Yes, it makes a lot more sense if you have local usage for it. Either say
an EV, timeshifting your loads (dishwasher, washing machine, etc), or just
having sufficient baseload that any solar displaces grid demand (more
relevant to businesses, although some people have more demanding equipment
at home).

If you can't do that, your loads are a bit lower return (ie you wouldn't
have otherwise run them from grid electric) - immersion (when you could have
used gas), an EV if you're on a cheap overnight charging tariff - so it's
'free' but you wouldn't have paid full price anyway.

With a battery it makes a lot more sense, but we aren't quite there on
battery cost yet (mostly lack of volume I think).

I'm curious what the OP wants to install for, BTW. If these are rented
properties, he's spending the money and the tenants are getting the benefit
of lower bills. So I wonder how that's worked out - does he get cashback
from the tenants' electric bills or something? Or just that it makes them
more attractive and so he can charge higher rent?
Post by Steve Walker
All government schemes seem to come with "approved supplier/installer"
lists, where any grants are completely cancelled by higher prices than
everyone else.
Indeed, that's annoying. However the way to think about the grant is that
you, as homeowner, don't get any benefits. What they're about is training
up the industry and stimulating demand for the kit. The equipment price
comes down, and now there's xx,000 installers who know how to install it.
So they taper off the grant and now you can go to the regular market and
pick up an unsubsidised quote at a lower price without any grant support.

The problem here is the 'MCS certified' which means even if someone is
trained they can't do a grid install unless they're in the
(paperwork-infested) club. Although I don't know if you can get an MCS
person to connect up an install that's already been done?

Theo
Andy Burns
2021-09-10 20:41:47 UTC
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I don't know if you can get an MCS person to connect up an install
that's already been done?
I think this answer (to a slightly different question) on the MCS
website tells you what you already suspected ...

Q:

I’m MCS certified and have been sub-contracted to complete some work for
another Installer who isn’t MCS certified, can I complete an MCS
certified installation?

A:

No, in order to ensure compliance with MCS 001-1, only MCS certified
Installers can enter into contracts directly with consumers.

If you don’t hold the contract directly with the customer, you won’t be
able to raise an MCS certificate. The Installer signing the contract
with the customer needs to be able to verify that the work undertaken on
their behalf meets the MCS Standards. If they’re not MCS certified
themselves, they won’t be eligible to do this.
Andy Burns
2021-09-12 16:48:36 UTC
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Post by Theo
The problem here is the 'MCS certified' which means even if someone is
trained they can't do a grid install unless they're in the
(paperwork-infested) club.
I hadn't seen DIY install systems before, ok so you won't get any
FIT/SEG payments, which are a pittance to start with, but it seems like
you *can* DIY install the kit, provided the hardware is MCS certified
and G98 grid-tied so you don't fry the DNO's staff ... is that legit?
Looks it from the PDF on the tech info tab

<https://www.roofgiant.com/flat-roofing-solar/plug-in-solar-4kw-4000w-diy-solar-power-kit-with-renusol-console-tubs-for-ground-or-flat-roof/>

Not amazingly cheap though ...
Theo
2021-09-12 22:19:47 UTC
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Post by Andy Burns
I hadn't seen DIY install systems before, ok so you won't get any
FIT/SEG payments, which are a pittance to start with, but it seems like
you *can* DIY install the kit, provided the hardware is MCS certified
and G98 grid-tied so you don't fry the DNO's staff ... is that legit?
Looks it from the PDF on the tech info tab
<https://www.roofgiant.com/flat-roofing-solar/plug-in-solar-4kw-4000w-diy-solar-power-kit-with-renusol-console-tubs-for-ground-or-flat-roof/>
Not amazingly cheap though ...
Yes, I'd seen those kits:
https://www.pluginsolar.co.uk/?product=plug-in-solar-2-5kw-diy-solar-power-kit-with-roof-mount-for-tile-or-slate-roofs
and that's what I was vaguely thinking of when talking about DIYing.

They use microinverters - while you can get a Chinese microinverter on
Aliexpress for £30-40 they aren't G98 certified, and the ones that Plugin
use are about £100 per panel. When you can get a 3kW inverter for 3x more,
it's not a cost effective way to go.

But it's interesting the way they do the DNO paperwork and I wonder
whether, by using microinverters, they manage to fly under the radar in some
way. I know G98 has special dispensations below 800W per inverter, so maybe
it's related to that. I should probably read up some more...

(I had originally started looking into this on the basis of duplicating
their setup, but then discovered how cheap regular inverters have become
now)

Theo
Andy Burns
2021-09-13 06:06:29 UTC
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Post by Theo
Post by Andy Burns
<https://www.roofgiant.com/flat-roofing-solar/plug-in-solar-4kw-4000w-diy-solar-power-kit-with-renusol-console-tubs-for-ground-or-flat-roof/>
Not amazingly cheap though ...
and that's what I was vaguely thinking of when talking about DIYing.
They use microinverters - while you can get a Chinese microinverter on
Aliexpress for £30-40 they aren't G98 certified, and the ones that Plugin
use are about £100 per panel. When you can get a 3kW inverter for 3x more,
it's not a cost effective way to go.
I suppose for a novice DIYer it means just 50V DC wiring between pairs
of panels, rather than about 500V DC for a complete string, but as you
say, no reason not to use a "proper" inverter

For G98 (where you inform the DNO) the limit is 16A per phase. If you
want more than 16A (on the AC side) you need to ask the DNO for
permission and use G99 kit.
Post by Theo
But it's interesting the way they do the DNO paperwork and I wonder
whether, by using microinverters, they manage to fly under the radar in some
way. I know G98 has special dispensations below 800W per inverter, so maybe
it's related to that. I should probably read up some more...
You can search approved inverters, e.g. 3.6 to 3.68kW

<https://www.ena-eng.org/gen-ttr/Index?Action=ViewDetail&EID=31770364&tab=search>
Post by Theo
(I had originally started looking into this on the basis of duplicating
their setup, but then discovered how cheap regular inverters have become
now)
Interesting, but without an MCS installer cert you're "unlikely" to find
a SEG tariff likely to accept you (if you have a cert they must accept
you, if you don't they can accept you, so it's not cut and dried)

If you generate more than you can consume then obviously the extra will
get exported anyway, without you getting paid, what happens at the
meter, do they still go "backwards" thereby saving you ~15p/unit
exported, or do the meters just disregard it?
Chris J Dixon
2021-09-13 07:58:27 UTC
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Post by Andy Burns
If you generate more than you can consume then obviously the extra will
get exported anyway, without you getting paid, what happens at the
meter, do they still go "backwards" thereby saving you ~15p/unit
exported, or do the meters just disregard it?
No meters these days are intentionally allowed to run backwards
with PV, though there may well still be some that do.

There was an interesting quirk with a certain electronic meter
which was capable of monitoring import and export separately. As
an anti-fraud measure, it could be configured by the supplier to
add the two together, so you paid regardless of direction of
flow.

Those unlucky consumers who added PV with a meter thus programmed
found that the more the sun shone, the higher their bills became.
There was quite a lengthy thread on MoneySavingExpert's forum at
the time.

Chris
--
Chris J Dixon Nottingham UK
***@cdixon.me.uk @ChrisJDixon1

Plant amazing Acers.
Theo
2021-09-13 21:54:01 UTC
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Post by Andy Burns
I suppose for a novice DIYer it means just 50V DC wiring between pairs
of panels, rather than about 500V DC for a complete string, but as you
say, no reason not to use a "proper" inverter
That's true. I did wonder whether there were multi-string inverters. That
would avoid needing optimisers - just run individual panels into the single
inverter, which would also keep the DC voltage lower.

I'd need to read up on safety of solar systems too - are there particular
earthing and protection requirements?
Post by Andy Burns
For G98 (where you inform the DNO) the limit is 16A per phase. If you
want more than 16A (on the AC side) you need to ask the DNO for
permission and use G99 kit.
I presume you can overspec the panels, there's just no point getting more
than a 4kW inverter unless you want to go G99.
Post by Andy Burns
You can search approved inverters, e.g. 3.6 to 3.68kW
<https://www.ena-eng.org/gen-ttr/Index?Action=ViewDetail&EID=31770364&tab=search>
Interesting, I hadn't seen that.
Post by Andy Burns
Interesting, but without an MCS installer cert you're "unlikely" to find
a SEG tariff likely to accept you (if you have a cert they must accept
you, if you don't they can accept you, so it's not cut and dried)
If you generate more than you can consume then obviously the extra will
get exported anyway, without you getting paid, what happens at the
meter, do they still go "backwards" thereby saving you ~15p/unit
exported, or do the meters just disregard it?
I think all smart meters, and maybe some non-smart meters, have separate
readings for import and export units. So they can tell the difference.

I did wonder how they know whether you have an MCS cert if your meter is
already reporting export, but it seems you can't switch to an export tariff
without one. Although Ofgem say:


1.12. For PV, wind and micro-CHP installations up to 50kW, applicants will
be asked to demonstrate that their installation and installer are suitably
certified. You may have an installation certificate to demonstrate this.
This may be a Microgeneration Certification Scheme (MCS) certificate, but
the SEG also recognises that other schemes may be equivelant to MCS.

1.13. If you do not have an MCS certificate, your installation and installer
should be accredited in accordance with EN 45011 or EN ISO/IEC 17065:2012.
You should speak to your chosen SEG licensee to understand exactly what
information they need from you.

1.14. If you are unable to demonstrate that your installation is suitably
certified, a SEG licensee is not obliged to offer payments under the SEG,
but they can make payments if they wish.
https://www.ofgem.gov.uk/publications/smart-export-guarantee-guidance-generators


So it sounds like they can accept you without MCS if they want to. It seems
that 'Flexi-Orb' is another standards body equivalent to MCS - I don't know
if the requirements on installs/installers differ.

Theo
Andy Burns
2021-09-14 08:23:49 UTC
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Post by Theo
I presume you can overspec the panels, there's just no point getting more
than a 4kW inverter unless you want to go G99.
I don't think any inverters greater than 3.68 kW can have G98 approval.
Post by Theo
So it sounds like they can accept you without MCS if they want to.
Yes, as I said above, if you have an installation cert they must accept
you, otherwise they can accept you, but I get the feeling they'd be
unlikely to.

So having MCS certified kit means you're allowed to install it, but
unless you use an MCS installer you'll probably be giving your surplus
away, overspeccing just means you're paying more upfront in order to
give more energy to the grid for free?

It seems the technical/approvals part of MCS is about safety and you can
DIY that, the "jobs for the boys club" part of MCS is probably more
about avoiding fraud against the SEG tariffs?

Obviously Nov-Feb are more or less a right-off in the UK, for a 3.6kW
system, to ensure you have sufficient storage capacity for the sunniest
days you'd probably need 7.5 to 10 kWh of battery, plus some demand you
can shift to the hours of darkness, or a car that can take a partial
top-up during the day.

It would gall me to have a battery bank sitting there and no be able to
flick an isolator and use it during a power-cut, looks like there's only
one brand of G98 approved "hybrid" inverters that can stash some energy
in a battery and run in either on-grid or off-grid mode ... inverter not
that much more expensive, but battery packs push the price up considerably.

<https://www.pluginsolar.co.uk/?product=givenergy-3-6kw-hybrid-pv-battery-inverter>
Theo
2021-09-14 21:04:34 UTC
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Post by Andy Burns
So having MCS certified kit means you're allowed to install it, but
unless you use an MCS installer you'll probably be giving your surplus
away, overspeccing just means you're paying more upfront in order to
give more energy to the grid for free?
Yes, if you're overspeccing there's not much point unless you can use it
locally.
Post by Andy Burns
It seems the technical/approvals part of MCS is about safety and you can
DIY that, the "jobs for the boys club" part of MCS is probably more
about avoiding fraud against the SEG tariffs?
That's a good point. I wonder if you can do the mechanicals and leave an
MCS installer to wire the electrical side - presumably if the panels are
part of a new roof then the roofers will install them? Is there an
equivalent first fix/second fix boundary?
Post by Andy Burns
It would gall me to have a battery bank sitting there and no be able to
flick an isolator and use it during a power-cut, looks like there's only
one brand of G98 approved "hybrid" inverters that can stash some energy
in a battery and run in either on-grid or off-grid mode ... inverter not
that much more expensive, but battery packs push the price up considerably.
<https://www.pluginsolar.co.uk/?product=givenergy-3-6kw-hybrid-pv-battery-inverter>
There's quite a few brands available - see the 'storage' section:
https://midsummerwholesale.co.uk
although some aren't cheap.

Theo
alan_m
2021-09-14 22:59:40 UTC
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Post by Theo
Post by Andy Burns
So having MCS certified kit means you're allowed to install it, but
unless you use an MCS installer you'll probably be giving your surplus
away, overspeccing just means you're paying more upfront in order to
give more energy to the grid for free?
Yes, if you're overspeccing there's not much point unless you can use it
locally.
But under-running electronics such as an inverter is likely to improve
reliability and longevity. It all depends how well the electronics have
been designed and how close to their maximum rating they are being run,
especially temperature on a dark roof or loft space during summer with
no forced air cooling
--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk
Theo
2021-09-15 09:47:01 UTC
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Post by Theo
Post by Andy Burns
I suppose for a novice DIYer it means just 50V DC wiring between pairs
of panels, rather than about 500V DC for a complete string, but as you
say, no reason not to use a "proper" inverter
That's true. I did wonder whether there were multi-string inverters. That
would avoid needing optimisers - just run individual panels into the single
inverter, which would also keep the DC voltage lower.
I found this one:
https://midsummerwholesale.co.uk/buy/SolarEdge/solaredge-compact-2000m-ext
(1, 1.5 and 2kW versions) that has a 4-input MPPT, so you could run 4 or 8
panels off that, and potentially have multiple inverters rather than
optimisers and a separate inverter.

The reason for thinking about this is residential solar is often compromised
in some way - shading from trees, non-optimal sun angles, birds pooping on
the panels, leaves, etc. So an optimiser or MPPT allows you to get the most
out of the site that you have, and if the cost is cheap enough you can
just fit more panels even if the placement isn't perfect.

Theo
Andy Burns
2021-09-15 11:18:04 UTC
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Post by Theo
residential solar is often compromised
in some way - shading from trees, non-optimal sun angles, birds pooping on
the panels, leaves, etc. So an optimiser or MPPT allows you to get the most
out of the site that you have
What do they do, effectively "short out" any panels that are giving low
voltage while they are in shade?
Theo
2021-09-15 11:40:55 UTC
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Post by Andy Burns
Post by Theo
residential solar is often compromised
in some way - shading from trees, non-optimal sun angles, birds pooping on
the panels, leaves, etc. So an optimiser or MPPT allows you to get the most
out of the site that you have
What do they do, effectively "short out" any panels that are giving low
voltage while they are in shade?
MPPT is maximum power-point tracking. MPPT optimisers are essentially a
DC-DC converter. The panel has a certain sweet spot it can yield most in
terms of I/V characteristics given the current illumination, but it can be
different for each panel (shading, panel size, ageing, etc). So the DC-DC
pulls the energy at the optimal panel I/V and then outputs a current to
match the rest of the string, adjusting its output voltage to control it.
This pushes the most energy out of the string into the inverter.

If the panel was completely blacked out it would have no output power and so
the voltage out of the optimiser would be 0V and look like a short, but if
the illumination was weak it would have some voltage and so still generate
some energy.

I don't know if it's all analogue feedback loops to communicate across the
string or whether the optimisers communicate. Multi-MPPT inverters have the
power electronics inside the inverter, rather than a module on the back of
the panel.

One advantage of optimisers on the DC side over AC microinverters is I don't
think they need to be G98, since they aren't attached to the mains supply.

Theo
Rod Speed
2021-09-15 19:50:50 UTC
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Post by Andy Burns
Post by Theo
residential solar is often compromised
in some way - shading from trees, non-optimal sun angles, birds pooping on
the panels, leaves, etc. So an optimiser or MPPT allows you to get the most
out of the site that you have
What do they do, effectively "short out" any panels that are giving low
voltage while they are in shade?
The best of them have a separate inverter on each panel.

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