Uncharted Territory

January 15, 2009

(G)Aga

Filed under: Biomass, Energy policy, Global warming, Media, Science and the media — Tim Joslin @ 8:10 pm

I’m sure that, like me, you woke on Tuesday, turned on BBC Radio 4, and heard the sensational news broadcast between 07:43 and 07:46 on the Today programme (please podify the paper review segment, Mr BBC!).  Yes,  George Monbiot had used his Tuesday Guardian column to start a campaign against the Aga!  The crusade was even flagged on the paper’s front page.

Actually, the Aga is only mentioned in passing in George’s column, mainly to make a rhetorical point, it seems.  The article is a bit of a ramble about class and green politics, and is more about flying than heating/cooking.  Perhaps it was the Guardian’s editor who decided to emphasise the Aga point.  Nevertheless, George claimed that:

“A large Aga running on coal turns out nine tonnes of carbon dioxide per year: five and a half times the total CO2 production of the average UK home…  So where is the campaign against  Agas?”

What made George’s article stick in my mind was that I happened to notice a couple of hours later on Yahoo! Finance that Aga’s shares were one of the day’s biggest fallers at that point.  Wow!, I thought, Monbiot is verily the Heineken of eco-babblers: he reaches parts other green commentators simply cannot get near.

But then I read in Wednesday’s Guardian that Aga had – coincidentally, or is George monitoring the company’s financial calendar?, is he a share-holder?, or maybe a short-seller? – announced poor results on Tuesday morning. The Guardian’s report (the online version, which apparently appeared first, has been edited in several places to produce the Wednesday print version) – supplemented by an amusing cartoon – drew heavily on George’s piece.  Graeme Wearden wrote:

“In a column in today’s Guardian, he [Monbiot] declared the start of a campaign against the Aga. ‘A large Aga running on coal turns out nine tonnes of carbon dioxide per year: five and a half times the total CO2 production of the average UK home,’ he [Monbiot] wrote. ‘To match that, the patio heater would have to burn for nine months.’ “

The numbers didn’t stick in my head, but I was mulling over whether an Aga is really an inefficient way to heat a home.

First off, I reasoned that if the Aga runs on oil or coal (apparently these beasts can run on practically any form of energy – I’ve just put myself on the waiting list for the nuclear-powered model) then it could be more efficient than some other forms of heating.  Virtually all the heat would be captured, which would not be the case for electricity generated in coal- or oil-fuelled power stations, which would suffer from energy losses, first, because not all the fossil-fuel energy would be converted to electricity (waste heat is lost at the power station, but useful at the Aga) and, second, during electricity transmission.

On the other hand, I understand we have to move away entirely from fossil fuels.  George mentions that Agas can run on electricity as well.  Great!  This can be generated renewably.

Would Agas be less efficient than any other form of electric heating?  No, of course not, since in both cases all the electrical energy converted goes into heat – normally when considering efficiency you worry about waste heat, but this doesn’t apply when heat is what you want!  OK, heat pumps would of course be more efficient as they use energy to extract heat from the environment, but we’re comparing the heating habits of different social classes in the UK today, and hardly at the moment anyone has a heat-pump.

With any conventional form of space heating the energy required doesn’t depend on the muscle of the heating system.  What it depends on is the rate at which energy is lost from the building.  Assuming the system has some kind of thermostat, and doesn’t stay on until the occupants of the house have died of heat exhaustion and turned to dust, what is important is the insulation of the property.  We only have to worry about the heat losses.  These might, of course, be higher than otherwise if heat escapes up a chimney, if the thermostat is turned up or if a heater is left on 24/7, as Agas tend to be.  But Agas cannot possibly be in themselves any less efficient than other heaters using the same energy inputs.

Sure enough, today’s Guardian bashfully includes a correction:

“A Comment article said that a large Aga running on coal turned out nine tonnes of carbon dioxide per year: five and a half times the total CO2 production of the average UK home. It is 35% more than the total produced by the average home (This is indeed a class war, and the campaign against the Aga starts here, 13 January, page 27).”

The text of the online version of Monbiot’s column has been amended, so no longer makes sense (in this case it might have been better to asterisk the text and put the error in a footnote).

We still have what appears to be a misleading statistic.  A “large Aga running on coal” is likely to be in a big, detached house.  It’s not that surprising such a heater/cooker produces 35% more CO2 than the average home, which must include much smaller properties, some of whose occupants perhaps can’t afford to keep themselves as warm as they’d like.   

George asks why there is a campaign against patio heaters and not Agas.  The point, of course, is that patio heaters heat the outside, which is a bad idea.

Bit of a bad day at the office for Monbiot, but what bothers me most about the issue is that, according to the Guardian:

“Aga said it had seen a shift of interest away from oil-powered cookers into wood-fuelled models over the last year, a time when the oil price soared to its record high of over $147 a barrel.”

Using wood, of course, is even worse than using oil, coal or fossil-fuel electricity.  The arguments against the supposed sustainability of biofuels apply to a biomass energy source like wood.

It turns out that the UK is already importing wood for stoves.  According to the SocietyGuardian Environment article:

“Britain grows up to 1m tonnes of domestic firewood per year, according to the Forestry Commission, but we also import up to 180,000 tonnes of wood and wood products. The 25% to 30% increase in demand for logs year-on-year is proving hard to satisfy, says Vince Thurkettle, a forestry and woodland consultant.”

Nevertheless, Thurkettle is optimistic:

” ‘The dramatic upturn in demand for firewood is fantastic news in many senses because, in theory, we have so much of this resource that it is hard to see it ever running out,’ Thurkettle says.”

The numbers must stack up then, mustn’t they?

“Convinced that the new love affair with wood is a long-term phenomenon rather than a temporary dalliance, the government’s current woodfuel strategy for England aims to bring another 2m green tonnes of wood to the market by 2020 – enough to heat around 250,000 homes.  …this represents less than 50% of the potential unharvested firewood already available in privately owned English woodlands.”

Adding the 2m tonnes to the 1m we already have and that’s 375,000 homes that could be heated by wood in Agas or otherwise.

Let’s be generous and double the amount of firewood we can produce.  That would get us to 750,000 homes.  Wow! , that’s a lot.

Trouble is, there are something like 20 million, that’s 20,000,000 homes in the country.  750,000 is less than 4% of 20 million.

So we’re already shipping logs in from eastern Europe, where, unlike the UK, there are still some decent forests.  Not for long, I fear.

Maybe George could let us know what he thinks about forests here and abroad being turned into ecologically barren tree-farms on behalf of the UK middle classes…

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