Oct 15 2008
Better house envelopes, more efficient energy supply systems, and use of biofuels for heating buildings would reduce CO2 emissions in Europe. Buildings account for 36% of Sweden’s energy consumption, and many homes are still heated with electricity. Existing houses therefore have a key role to play in reducing the use of electricity in Sweden.
Since a major share of European electricity comes from fossil fuels, exporting Swedish electricity can help reduce CO2 emissions from coal-fired power stations. This is shown in a dissertation by Anna Joelsson at Mid Sweden University. She has performed analyses of complete energy supply chains, from the natural resource to the electricity and heat in houses and shows that existing houses have a key role to play in lowering the use of electricity in Sweden.
“An improved house envelope and conversion from electric heating to district heating based on cogeneration can reduce primary energy consumption by more than 70% in a standard home built in the 1970s,” says Anna Joelsson. “Energy efficiency is important if we want to make the best possible use of limited natural resources like biofuels.”
Among other things, she compares various fuel-based energy systems and singles out bedrock heat pump and district heating based on cogeneration as particularly energy efficient. What’s more, her analysis shows that conversions to all of the studied systems are profitable from a socioeconomic perspective.
When you build new houses you have ample opportunities to make them well insulated and well sealed, thereby achieving low heating requirements. However, Anna Joelsson claims that it is important not to forget the supply systems.
“A newly built passive house with fossil-based electric heating can entail higher primary energy consumption and CO2 emissions than a 1970s house with an efficient biofuel-based heating system.”
Anna Joelsson from the Department of Engineering and Sustainable Development at Mid Sweden University recently defended her dissertation titled Primary Energy Efficiency and CO2 Mitigation in Residential Buildings.