Zero Carbon, Zero Reality? Part 1

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Wood-Burning Appliances








It was alleged this week that the Department of Energy and Climate Change has been suppressing the ‘biomass calculator’ developed by its Chief Scientist, Professor David MacKay. To quote Prof. MacKay, this modelling tool makes it ‘fantastically [clear]‘ that over the next 20-30 years, burning wood is worse for climate change than burning fossil fuels [1].

The main reason for this awkward finding is that if trees are cut down and burned it takes a very long time for new trees to regrow to replace the combusted material. During the initial part of this period, the bulk of the CO2 which was emitted remains in the atmosphere and contributes to climate change.

The overall situation is not that burning fossil fuels is less bad for the environment than we thought. It is that wood burning is even worse for the environment than we thought. A lot of people outside government have been criticising the belief that wood is ‘near-zero-carbon’ for several years [2]. But it was a welcome move for a government scientist to acknowledge the point.

What makes it politically difficult is that a ‘dash for biomass’ is already well underway. With much fanfare, DECC launched its ‘Renewable Heat Incentive’ (RHI) which gives large subsidies to the users of heating systems which burn wood instead of oil or gas. 12 pence per kWh of heat is on offer for owners of approved wood-burning appliances [3].

The stately homes of England – Downton Abbey, indeed – could end up scrapping their oil-fired boilers for wood-fired ones. Drax power station may start burning shiploads of imported trees from the USA. The government probably depends on the truth of the assertion that wood burning is ‘zero carbon’ and hence ‘renewable’ to have a good chance of meeting its target of 15% of UK energy from renewable sources by 2020 [4].

It would be awkward to have to admit that certain devices which have been receiving a government subsidy risk making climate change worse, followed by hurried amendments to the rules of the RHI. Yet this would seem to be the honourable course of action to take.

Could the government be continuing on a technically flawed course in order to avoid something as basic as political embarrassment? I rather fear so.

No doubt the Secretary of State and his officials could not possibly comment. But energy consumers and taxpayers deserve better. They will pay for this folly in higher bills and taxes, yet the atmospheric concentration of CO2 will be as high as or higher than it would otherwise have been.

Part 2 of this blog will follow shortly. It deals with another technology subsidised by the ‘Renewable Heat Incentive’ which could risk causing more problems than it solves.





[1] Private Eye, no. 1365, p. 32, 2-15 May 2014. The article asks if DECC may be able to stop release of the calculator using the argument that the government, as employer, owns the intellectual property generated by its employees. The Freedom of Information Act might still apply though. Note added on 27 June 2014: DECC informed the author that the calculator is now called the Biomass Emissions And Counterfactual Model and ‘will be published shortly’. Further note: the calculator was published on 24 July 2014.

[2] Many academic papers make similar points in greater detail. The matter is quite complex. A full study should take account of all other greenhouse gases, including methane, large and small soot particles and nitrogen oxides.

It should also look more critically at changes on the fossil fuel side. For instance, the emissions from ‘unconventional natural gas’ and from conventional natural gas transported as LNG are higher than from the piped natural gas we consumed for the last 40 years.

[3] It seems likely that most wood-burning installations will replace oil. This is the usual heating fuel in large rural properties.

[4] It is not so much that the target is vastly overambitious, given the higher percentage of energy coming from renewables in other EU states, except for Luxembourg. Rather, the UK has been slower to develop a policy on heat or transport fuel than on electricity. Possibly officials were not fully clear what they were signing up to. Did they confuse energy with electricity?