Towards Solar District Heating with More than 70% Solar Fraction

In Denmark solar fractions up to about 50% are seen for large scale solar district heating systems. The feasibility of higher solar fractions has been investigated in a case study. There is no direct subsidy for solar heating in Denmark, but the taxes on the alternative (fuels) affects the feasibility of solar heating for any district heating plant. The results show that solar heat can be provided at competitive costs compared to what is seen at many Danish district heating plants. The utility in the case study has not yet decided on a solar district heating system size.