Aalto University, the Co2mmunity partner implementing the RENCOP in Helsinki, has developed a comprehensive overview on renewable heating within district heating in Helsinki. A short article on the homepage of Aalto University also provides some key points. One main component proposed is to use wind energy to power large heat pumps. Already since 2006 the biggest heat pump in the world produces 100 MW of heat under the Katri Vala Park in Helsinki. And only 10 such heat pumps could power the whole district heating system of Helsinki.
Generally speaking, it is not very efficient to use electricity for heating, as for example electric space heaters do. Especially when using electricity generated from fossil fuel the combined efficiency can be well below 30% of the original fuel source. Heat pumps however leverage the energy by taking advantage of existing temperature differentials in the environment. Therefore heat pumps can provide a multiple of the electricity invested in the form of heat and boost overall efficiency. The discussion paper by Aalto University proposes to use the heat pumps in an integrated system with wind energy, CHP plants and heat storage to provide both heat and electricity when they are needed. Surely, this would be a great step towards an integrated energy system.