There is a political ambition to gradually phase out fossil fuels in favour of an energy systems based on renewable energy sources and most actors of the energy sectors consider electric heat pumps a central element in this development. Currently, however, the implementation of heat pumps is developing slowly and largely loosing terrain to solar thermal operating under a more favourable legal and economic framework.
The purpose of this study is to analyse whether the current popularity of solar thermal could become a problem for the desired implementation of electric heat pumps in the district heating sector. The analysis takes its point of departure in a generic district heating plant dimensioned to simulate the type of plant typically investing in solar thermal or electric heat pumps. Using the energy system analysis software energyPRO simulations of different scenarios are carried out and the results form the basis of an economic calculation estimating the net present value of an investment with a time horizon of 15 years.
As a first part of the analysis the feasibility of investing in solar thermal and electric heat pumps individually is calculated concluding a higher feasibility for a solar thermal solution. Following this, the feasibility of a solar thermal district heating plant to investing in a heat pump is calculated. The robustness of these results are tested in a series of sensitivity analyses, including varying electricity and gas prices, varying heat sources for the heat pump and changes to existing tax, tariff and subsidy structures. The study concludes that the economic feasibility of investing in a heat pump is severely reduced by the investment in solar thermal. However, the sensitivity analysis shows some potential especially if the heat pump is exempted from the PSO tariff.