(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

[fivemack.livejournal.com]

I don't like developments which make economic sense only in the face of odd local subsidy regimes; I can't see why, given that Australia has a national grid, Epuron's demand that NSW be obliged to source renewable power only from within the state of NSW makes sense. Also I don't see why it helps, since NSW already has 4GW of currently-operating hydro plants [yay! data! http://www.ga.gov.au/renewable/operating/operating_renewable.xls ].

Maybe hydroelectricity is unreliable in the face of the substantial drought that has been afflicting Australia these many years.

I suppose everything makes sense only in the face of the current subsidy regime that puts the cost of dealing with CO2 emissions entirely on the taxpayer: even a small portion of the cost of the building works to deal with a two-metre sea level rise in Sydney would bankrupt Loy Yang many times over.