Research on distributed energy systems led by the VTT technical research centre of Finland concludes that solar heating in combination with a ground source heat pump is cost-effective for the on-site heating of buildings.
The DESY (Distributed Energy Systems) project explored the use of hybrid solutions to enhance the efficiency of heat and electricity production in buildings. A hybrid solution combining a ground heat pump with solar heating turned out to be the most efficient solution with the lowest life-cycle costs.
The goal of the project was to produce energy close to the consumption site by using hybrid solutions in order to generate electricity and/or heat for the buildings in question.
DESY project results show that solar energy used either as heat or as electricity is a good way of reducing the amount of sourced electricity needed in addition to a ground heat pump. Solar power was particularly efficient when combined with ground heat in terms of the profitability of investments. The payback period for an investment is between five and six years.
The combination of solar and district heating is also profitable, provided that the solar energy replaces boiler capacity, which involves higher production costs, between spring and autumn. The local district heating network can also be used for the temporary storage of surplus heat produced by buildings.