Tuesday, 3 March 2009

Renewable Gas ?

We have tended to bracket gas, along with coal and oil, as the problem – “non renewable fossil fuels”. But natural gas is methane, a product of the decomposition of organic matter. It is a pollutant and a greenhouse gas when it leaks out of sewerage works and council landfill sites, but potentially it is a fuel. Can we turn this problem methane – which is currently an argument for incinerating waste - into a low carbon energy source?

National Grid has recently produced a study, which says that a substantial part of North Sea gas production could be replaced by controlled bio-digestion of wastes; domestic, commercial and agricultural. Dry gasification by heating in the absence of air may be useful for solids like timber. The gas could be injected into the existing gas grid. Half our domestic heating needs could be met in this way, says the report. It would all be recent solar energy, fixed by plants, potentially both low carbon and renewable. Anything that was once alive can be gasified, potentially. The only drawback is that all this carbon would go straight to the air and have no chance to be locked in the soil (as with composting).

Gas can be piped, stored, even compressed. All the systems to distribute and use it are already in our buildings. Most of the housing of the future is already built and what we see around us. We must insulate and use solar hot water, but will still need a store of winter heat. Renewable gas is well suited to this role. We can even make electricity with it, using combined heat and power boilers or fuel cells, which are starting to be available at domestic scale.

We usually think of renewable energy in terms of sun, wave and wind generated electricity, but most of our energy requirement is actually for space heating. Perhaps environmentalists need to talk more to the gas industry.
John Newson
See more at http://www.nationalgrid.com/uk/Media+Centre/PressReleases/02.02.09.htm

1 comment:

Birmingham Friends of the Earth said...

Hi John, great article. Just thought I'd mention something though. You say that a downside to renewable gas systems is that all the carbon goes into the atmosphere, but actually it doesn't. None of the current systems, whether it be bio-digestion or pyrolysis, are 100% efficient, meaning that some solid carbon is left, either in the form of sludge or charcoal. Both of these can be applied to land, making it more fertile and locking CO2 into the soil; so it is in fact win-win. Check out this article on the BBC for more info on pyrolysis and biochar http://news.bbc.co.uk/1/hi/sci/tech/7924373.stm