Towards District Heating with 80-100 % Solar Fraction
Abstract
The implementation of a large scale solar heating system to supply a district heating network which stands in front of an upcoming expansion (to cover three more villages) has been investigated. This includes the feasibility study of aiming for large solar fractions. The result is that a solar heating system which can supply the entire heat demand of the expansion will be more feasible than only operating with biomass boilers. The study also investigates the possibility of going one (big) step further to reach solar fractions in the range of 80 % not only for the expansion, but for the entire district heating network with an annual heat demand of approximately 60,000 MWh. The results indicate that the cost of having a heat supply with a solar fraction of around 80 % would match the cost of a biomass based supply if a new tax on biomass would have been approved. It has later been decided to drop the implementation of this tax and without it the most feasible solar fraction is significantly lower for the specific case. However the average heat price for a system with high solar fractions is in the range of typical district heating production costs for other fuels than biomass (e.g. natural gas) thus making it a potential option for future district heating solutions.
Keywords
Solar district heating, Large scale, Solar fraction, Business model.