In English

Importance of Swedish Cogeneration Plants for the Domestic Energy System and the North European Power Exchange

Mubashir Virk
Göteborg : Chalmers tekniska högskola, 2011. 50 s.
[Examensarbete på avancerad nivå]

This report examines Swedish cogeneration importance for the domestic energy system and for the North European power exchange. Carbon dioxide emissions and generation cost of Swedish cogeneration is compared to imported or that by export replaced average electricity to and from Sweden. The comparison is for a historic period (2005-2010) where known annual electricity exchange data and cogeneration generation by fuel is used to compare actual emissions and cost. And a future period (2011-2020) based on the NREAP report, where projected electricity and cogeneration investments are used to estimate future CO2- emissions and generation cost. Also the new Rya NGCC CHP plant is compared to the North European marginal electricity generation for the historic period (2005-2010). The comparison is based on emissions of CO2, NOx and SOx. The method uses fixed values for emissions factors, generation prices and fuel to energy efficiencies based on qualified sources for average values. The comparison is visualised in both diagram and tables. The result implies that the imported electricity has lower CO2-emissions compared to Swedish cogeneration. However when removing Norway from the comparison the result is different, now the imported electricity has higher CO2-emissions. The comparison for Swedish cogeneration and the by export replaced abroad average electricity is different annually depending on how much electricity Sweden exports to Norway. Removing Norway from the comparison makes Swedish cogeneration better from an emission point of view. The estimated generation cost of both imported and exported electricity is lower than Swedish cogeneration, even when the heat income from sold heat is accounted for. If Norway is once again removed from the comparison , the results shows that the generation cost of both the imported and by export replaced average electricity is similar to Swedish cogeneration. As cogeneration also generates useful heat it can be assumed to be a better alternative compared to the average electricity generation in these countries. Swedish cogeneration can however not compete with the cheap and emission free Norwegian hydro power. Future CO2-emissions will decrease faster for the North European average electricity compared to Swedish cogeneration, but will still be higher. The cost of generating this electricity will still be higher than Swedish cogeneration but the gap will decrease. Sweden will based on the results join Norway and generate enough CO2-free electricity by 2015 to meet its annual domestic needs. The efficient Rya NGCC CHP has lower emissions compared to marginal electricity in Northern Europe. The use of natural gas which is the cleanest fossil fuel alternative and the lower average efficiency in the abroad power generation makes Rya a relatively clean facility. Especially when keeping in mind the high heat demand that exists in Gothenburg’s urban area during winter season when Rya is operated.

Nyckelord: average electricity, emissions, generation cost, marginal electricity, Rya NGCC CHP, Swedish cogeneration

Publikationen registrerades 2012-01-11. Den ändrades senast 2013-05-31

CPL ID: 152455

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