On Wed, 13 Jan 2021 14:30:07 +0000, The Natural Philosopher
Post by The Natural Philosopher Post by David
Looking at Gridwatch, coal is fired up but Biomass which has been running
flat out is now throttled back.
A cynical thought is that Biomass generation is by converted coal plant
(IIRC) at the same site, so has someone decided to get their money's worth
by firing up the coal plant and easing back on Biomass?
They could get more by doing both - and its Drax, not 'someone'
My guess is that a boiler is down for maintenance. IIRC they had 4 1.2GW
coal boilers feeding 8 600MW generators (industry standard size) .
3 of those now burn wood and other biomass exclusively, they other one
may still burn coal, I am not sure. If one of them is down that's 3GW
down to 2GW.
Nope, pre-biomass conversion it was six dedicated boilers each individually
feeding six team turbines with 6 x 660MW electrical output (gross) Unit
consumption at Drax is around 15MW giving a maximum net output of 645MW, when on
coal each of the units at Drax could be overfired at 680MW for up to 30 minutes.
Range boilers where several boilers could feed into a common steam rail ended in
the UK with the demise of the up to 60MW units in the 1980's (1950's build)
120MW units (late 1950's onwards) were always unit based, one boiler per
turbine, but there are some oddities built in the early 1960's such as Blyth B
and Thorpe Marsh that had either two boiler combustion chambers or cross
compound turbines (or both) but regardless they were all unit and not range
Post biomass conversion things changed. Drax unit one is rated at 660MW net, all
the other units are still rated at 645MW net.
Units one to four have to operate on Biomass, units five and six have to operate