Halfway I hope... by ingermaaike2, on Flickr
Let’s start with a quick question.
The UK is currently committed to reducing its greenhouse gas emissions by at least what percentage by 2050, relative to 1990 levels?
[Answer at the bottom]
The Department of Energy and Climate Change has a section on its website relating to a low-carbon UK and the above commitment.
There’s a fascinating calculator tool that allows you to balance the UK’s energy demand with the energy supply and monitor the resultant greenhouse emissions.
It’s a bit like playing SimCity and other ‘strategic life-simulation computer games’.
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Consider what the average temperature of homes should be.
DECC reports that the mean internal temperature of UK homes during the winter months was 17.5°C in 2007 compared to 16°C in 1990 and 12°C in 1970. Historically, the temperature people choose to heat their homes at has increased over the years.
You’re offered various choices ranging from letting this growth trend continue to 20°C by 2030 through to reducing average internal temperatures to 1990 levels.
The commentary is amusingly sobering. ‘Householders can experience today’s levels of thermal comfort whilst also reducing energy demand by wearing warmer clothing or by heating the house in a smarter way.’
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Or how significantly should home insulation be improved.
This time your choices range from reducing leakiness by between 25 and 50%, with varying percentages of the existing housing stock being upgraded (floor insulation / cavity wall insulation / triple glazing) and all new houses being built to Energy Saving Trust or even PassivHaus standards.
The most stringent level would half the power required to maintain a given temperature, although this would be partially offset by a growing housing stock and any failure to reverse the trend towards warmer homes.
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And it goes on to cover how we heat our homes and businesses, the efficiency of our lighting and appliances, how we travel and how goods are moved around.
And then it’s on the supply side. How many nuclear power stations should there be? Or carbon capture and storage power stations? How many wind turbines? How much of the agricultural land should be devoted to growing biofuels? Should the numbers of methane-producing livestock be reduced? Have you considered harvesting marine algae?
And what level of energy security do we need? What do we need in reserve if there’s a cold snap or an incoming pipeline is closed down?
It’s actually quite difficult to do.
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There are also example pathways from experts and interested parties.
Everyone broadly agrees that demand needs to be reduced by around a third, which usually encompasses electrifying domestic transport, shifting up to 50% of freight off roads to electric railways, making planes more fuel efficient and building to PassivHaus standards.
It’s on the supply side that there are disagreements. Friends of the Earth achieves the 2050 target with no new nuclear or carbon capture and storage, and a heavy emphasis on onshore wind turbines, solar energy and geothermal electricity. Whilst the Energy Technologies Institute take a broader mix of supply sources, including 13 new nuclear power stations along with wind, wave and hydroelectric sources.
Have a look – it’s thought provoking.
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[80%. Which is a lot.]
Building Design 