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?
Cheers
Dave R
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.
Further to that, this suggests that DRAX4 and 5 are down till the end of this week
Reason for Unavailability Boiler / Fuel Supply
They've sent the lad out to buy some firewood, having used it all up during the cold/dark/unwindy spell the other week?
might he get help from GK Wenceslas?
There was a supply interruption here (mid Herts) at 1.00am. Short duration and *on the hour* so probably routine switching but annoying as it woke me up!
>
Agreed (could be the "handling" plant, assuming they have not actually run out. Coal stacks and plant have problems with ice and freezing in the winter.)
Can't just switch a boiler between coal and wood. Coal plants are "lit" using oil, ISTR that some can be "duel fuelled" with oil or coal.
Depends on how efficient the plant is at burning coal cleanly I suppose. Brian
Completely OT, but seeing the title of the thread reminded me.
Did you see the Channel 5 programme on Wednesday last week "The Thames. Britain's great river with Tony Robinson"? A fair bit of it was recorded in the old Battersea Power Station. There was a longish section in the Control Room, which is being conserved and the roof section reglassed and redecorated (all being sanded down by hand!). A quite amazing number of analogue meters were on view with the area of London each section powered being shown. See photo at
Site shows 1.82 GW biomass. 3.28 GW coal. Does each boiler power a pair of generators? [Seems reasonable from those numbers.] If so, assuming that the (3 * 1.2) gives 3.6 GW at full chat is the meter on Gridwatch slightly under, given that it seems to stop at 3?
Either way I assume there must be other coal sites fired up to get up to
3.28 GW from coal.Ratcliffe and West Burton plan to keep running for the moment, and can supply 2 GW each.
Is there anywhere which shows which cal plants are fired up at the moment?
Idle curiosity as usual.
Cheers
Dave R
Also noting that the OCGT is fired up at the moment whilkst the CCGT is nowhere near the stops.
Do we have a lot of capacity not working in CCGT?
Just puzzling over the economics.
Cheers
Dave R
I wonder if other kids at school sung "Good King Wenslas last looked out" ?
Bill
No but nice heads up, I will try to watch it later. I never went to Battersea but my first posting (pre-university, as a CEGB Scholar) was to Kingston upon Thames which was similar technology. Four 25MW sets with chain grate boilers. Lots of nice polished brass.
more gas being used directly for household heating???
And where is this place 'Orientar' from whence the three kings hail?
Why is the holly-bear a berry?
Why is Amazon still recommending carol CDs?
perhaps they need the storage space for Easter Eggs?
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 based.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 on coal.
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You can use oil up to about 30MW for a short while on some 500/660MW units if the boiler is already hot enough, otherwise you destroy the turbine blades with the wet steam. It's bloody expensive though and only really intended for flame stabilisation before getting a coal mill in service. Ignition of the oil is with piped propane.
In the very early days of trialling biomass (2005 ish?) Drax dual fired coal and wood with one or two modified coal mills being fed with wood pellets
The original Didcot (4x500MW) could operate on natural gas or coal
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Some OCGT capacity is converted CCGT capacity, there is around 2GW of CCGT offline and mothballed since May 2020 when the operator went into administration.
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