(no subject)

[fivemack]

A Greenpeace article

http://www.greenpeace.org.uk/blog/climate/greenpeace-shuts-down-coal-fired-power-station-20071008

includes the line 'And it will only be 45 per cent efficient, in an age when power stations can reach 95 per cent efficiency'.

This is a coal-fired power station, so 45% efficiency in converting thermal to electrical energy is I think extremely good.

95% thermal efficiency implies, by the Carnot equation, that the heater is twenty times hotter in Kelvin than the heatsink and that there are no other thermal losses in the system. With a heatsink laid on an infinite icefield at zero centigrade, the heater has only to be hot enough to boil tungsten. I was unaware that gas-cored fission reactors were either in production, or this enthusiastically endorsed by Greenpeace.

Comments

[cultureofdoubt.livejournal.com]

Weird. I struggle to think of any measurement of efficiency that would be 95%.

[fivemack.livejournal.com]

Reading the blog comments, it turns out that their '95% efficiency' is for combined heat and power installations - pump the hot combustion gas through heat-exchangers after it's been through the turbines, and provide either process heat for a nearby oil refinery or free hot water to all the nearby houses.

There aren't any very nearby houses, and rebuilding the central heating of every house in Gillingham doesn't strike me as particularly feasible; the power station is located on the Essex coast in just the kind of place that I imagine would garner complaints from Greenpeace were it to be used as the site for a new oil refinery.

http://maps.google.co.uk/maps?f=q&hl=en&q=Kingsnorth,+Medway,+United+Kingdom&ie=UTF8&cd=2&geocode=0,51.428608,0.597117&ll=51.389566,0.577469&spn=0.136257,0.32135&z=12&om=1

But 'Greenpeace pushes for coal-fired power station design also to include new oil refinery' would be a rather more difficult headline to sell.

To call a process which ties the heating for a hundred thousand houses irrevocably to a local power station (do you want to live near a 1.6GW coal-fired power station?) 'decentralisation' feels a little off; I can't help thinking about the various places in Sibera that were set up like this and are now sitting there with the owner of the inefficient and uneconomic power station unable to close it because the local inhabitants would freeze.

[cultureofdoubt.livejournal.com]

I was starting to think it was maybe some very efficient hydroelectric or tidal thing, which would be more Greenpeacey. But yes, sounds like they're really not representing the situation very well.

[del-c.livejournal.com]

That URL does strange things to LJ margins. This one seems to work just as well.

http://maps.google.co.uk/maps?q=Kingsnorth,+Medway&ll=51.389566,0.577469&spn=0.136257,0.32135