Apparently carbon emissions from coal plants were previously underestimated by half by British scientists advising the British government on the best ways to reduce electricity demand. That revised rate is 0.69 kilograms of carbon dioxide per kilowatt hour of consumed electricity, not 0.43 kilograms.
They were using an estimated figure for emission rates that the new study shows was 60 percent lower than the actual rates observed between 2002 and 2009. The error came partly because they were averaging nationwide emissions. The numbers were to determine how much carbon would be saved by policy encouraging all Britains to, for example; change their light bulbs.
But, just as here, some regions of the UK are powered by clean energy that emits no carbon, while others are powered by relatively dirty energy. Here, for example Wyoming is over 95% powered by coal and every year, Hawaii spends over $5,000 for oil to power each homeowner while Maine is 55% clean powered by a variety of non carbon-emitting sources, including 30% hydro-power.
The error also came because they were not taking into account that only fossil-fueled electricity is used to respond instantly to changes in electricity demand. Dr Hawkes drew upon 60 million data points showing the amount of electricity produced in each half-hour period by each power station in Great Britain from the start of 2002 to the end of 2009.
Dr Adam Hawkes, the author of the new study from the Grantham Institute for Climate Change at Imperial College London wants to ensure that policy decisions for reducing emissions are based on robust scientific evidence, so he wants to exclude non carbon emitters, like nuclear or wind-powered electricity, and focus on only fossil fuel power stations that are typically used to respond instantly to changes in electricity demand.
Rather than find a general average nationwide climate benefit to saving electricity (by, for example switching out light bulbs), by focusing on just those regions where electricity is primarily supplied by dirty energy like coal, policy makers would get a more accurate number for those regions where it really would make a difference.
This would have implications for climate legislation. For example, it would be much more carbon-cost effective for a government to, say, double the incentive for homeowners in places like Hawaii or Wyoming to go green, rather than to spread an incentive more thinly across both clean powered regions and dirty energy regions.
Hawaii depends on oil for electricity. So if we all help Hawaiians change their light bulbs, we’ll reduce our carbon emissions more than if we spread the same incentives around.
Based on the speed at which Wyoming homeowners snapped up incentives for home solar and wind power under the Recovery Act, which is investing $90 billion in clean energy, homeowners in dirty energy regions in this country do seem to be fully aware of this much greater benefit already.
Image: Island Breath
Source: Science Daily
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