(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

[randwolf.livejournal.com]

They are arguing for what they call combined heat and power; re-using the waste heat of power stations. This is indeed very efficient, though perhaps not the best solution. Their objections to coal-fired plants are valid. And, you know, they're doing something. Perhaps not the best thing. But the people who could do the best thing aren't doing any damn thing. So why the objection?

[fivemack.livejournal.com]

My main objection is that trying to get a power station to drop off the grid is a very fundamental assault against the public good - if the people doing this were Muslim students from Birmingham rather than professional demonstrators from Greenpeace, they might well have been shot by now - and not something that should be done to make a minor and unrealistic point. There's a line somewhere between trying to stop whaling and nuclear-bomb tests, which are activities mostly without obvious positive consequences, and attacking the infrastructure that keeps us from starving, shivering in the dark.

Another annoyance is that the article fails to mention the trade-offs: the comments point out that they haven't found an application in Gillingham for two gigawatts of heat, and suggest that the power-station be scaled down to something that generates only the amount of heat usable in Gillingham. But the electricity demand is fairly fixed, so if you're building tiny power stations you do need to build lots of them, and you therefore need either to transport huge amounts of coal densely within the country, or to run everything on conveniently-piped natural gas and trust to the enlightened benevolence of Vladimir Putin and Dimitri Medvedev. The consequences of their arguments are either 'build a large oil refinery in Gillingham' or 'we ought to be building twenty times as many power stations as we do', and I feel they ought to mention those consequences.

I'm pleased to see that somebody has got planning permission for a square kilometre of CHP-heated greenhouses in Thanet (google 'thanet earth') - they're what I think of when I hear food-miles arguments. Though I can't find the electrical power output of the CHP mentioned anywhere; if you're going to build a facility to convert natural gas into cucumbers, you might as well generate electricity as well, but I'd like to know what proportion of the cash flow comes from kilowatt-hours and what proportion from cucumbers.

There is an interesting advertising exercise in promoting the pineapples from a potential giant greenhouse built at Hunterston to use the heat from the waste water of Hunterston B; to convert plutonium to xenon and strontium and thereby to grow pineapples in Ayrshire in the depths of winter is a great and useful miracle, but to convince people to buy the pineapples might require a greater one.

[randwolf.livejournal.com]

But it's not a minor point; Greenpeace is quite right that the construction of new coal-fired plants is a very wrong-headed thing. I, too question their solution to energy problems, but surely the sensible thing to do is to work on better solutions, rather than protesting the protests; if you side with Gordon Brown, you will get nowhere. As for shooting protesters, be glad that your government at least is still somewhat responsive and in check; in the USA, these people might have already been killed.

[jiggery-pokery.livejournal.com]

There is an interesting advertising exercise in promoting the pineapples from a potential giant greenhouse built at Hunterston to use the heat from the waste water of Hunterston B

Did you choose that station purely at random from among the nukes or did you deliberately pick one whose two reactors tripped (http://www.bmreports.com/servlet/com.logica.neta.bwp_PanBmData) on Wednesday (this is public data; search for BM units T_HUNB-7 and T_HUNB-8 for settlement days 2007-10-04 to 2007-10-08, period *) and have not yet returned to generation? (Also... (http://news.independent.co.uk/business/news/article2091904.ece))

I also note RWE's planned coal-fired station at Blyth (http://www.rwe.com/generator.aspx/presse/language=en/id=76864?pmid=4001632), with coal coming into the Tyne and up a disused-but-repairable railway track. I don't think that quite makes Northumberland the equivalent of Siberia, but it's still fun to compare. Some people reckon that EU emissions allowances need to be floating around the €30-40 mark before serious investment into clean coal becomes profitable, and Phase 2 has been more or less rangebound (to within +/- 5% or so) over the last month, as previously discussed. At least one major European financial player has suggested there's a lot of upside potential on the contract, though.

I would ask for danger money for working on a coal plant these days

[jiggery-pokery.livejournal.com]

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

Damn straight! I think new closed-cycle gas turbine / steam turbine units get up to about 56% efficiency these days, though, but it's more about accountancy than thermodynamics at this level - what value you place on work done by the recovered steam, for instance, especially if you're calling it Combined Heat and Power and getting it to heat other stuff off-site as well.

I fear Greenpeace may not necessarily be using the word "efficiency" the way you are and that this 95% efficient station is measured in some other context apart from thermal efficiency. Not sure what this 95% efficient station would be, how large it is and what sort of load factor it has. That said, I half-recall hearing that pumped storage hydro stations are remarkably efficient, reclaiming something like 70% of the energy required to pump the water uphill. Not bad for fifty-plus-year-old technology!

[tau-iota-mu-c.livejournal.com]

A German bunch want to generate a gigawatt (4% of NSW needs) using wind in Broken Hill, but the NSW government don't want to commit to buying it, saying there's not enough wind here despite the investors saying "um, yes, there is. Look, here's our money".

But the NSW government are going ahead with plans to build a new coal fired power station that will still have to be operating in 50 years, despite er, 50 years from now being not a very good time to be stuck with coal fired power.

I'm with Greenpeace on this, as I was back when Real Action shut down Loy Yang a couple of months ago.

[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.

[rwl.livejournal.com]

45% fuel-to-electricity efficiency for a coal-fueled power is very good. It has to be some kind of advanced technology like integrated gasification combined cycle to do that. The waste heat can be used for other purposes, true, but most of them would require some significant infrastructure improvements. One possible use that would not require a lot of capital investment would be heating greenhouses in the cold winter months. That's already being done with waste heat elsewhere in the world.

[(Anonymous)]

Ah, Greenpeace just love invading power stations. They did something similar to Didcot A about 10 months ago. I don't think that they realise that the demand for power needs to be met, so National Grid will just use the Balancing Mechanism to call plant on to replace the generation that has been lost. It's entirely possible that by taking out coal plant at peak time, you force oil stations (such as Fawley and Littlebrook) on. Which doesn't help the environment one bit.

The major problem with the massive push for renewables that is being advocated is that there simply isn't the transmission infrastructure present in the UK to connect all of the wind generation that wants to come on - at present we can only shift about 2.2GW of power from Scotland (where there's lots of wind, and lots of wind farms that have applied for connection) to England (where there's lots of demand). It doesn't help that when SSE and SP applied to build reinforcement power lines from Beauly to Denny, the application got stuck in the quagmire that is a public inquiry.