Prospects for Solar District Heating in Europe
Conference contribution, 2008
In total, there are about 20 million m2 of glazed solar collectors in Europe, corresponding to about 14 GWth (thermal power), where the majority of the collectors are installed in small systems with up to a few kWth. European large-scale solar heating plants having more than 500 m2 (~350 kWth) of solar collectors have only about 135 MWth altogether, so only a minor part of the European collector market comprises large-scale applications, i.e. about 1% of the installations. However, the relevant heat loads vary from a few kWth up to several GWth and about 9% of the heating loads in Europe are covered by block and district heating systems. There is thus a need to develop large-scale applications in order to utilize the full potential of solar heat to cover existing heat loads. The further development of district heating systems is likely to play a major role on the future European energy market, e.g. in Germany and Poland. To acknowledge the importance of large-scale solar heating (and cooling) systems, the European Solar Thermal Technology Platform – ESTTP - has assigned one working group for Solar District Heating (and Cooling). The vision for large-scale systems is further developed in co-operation with representatives for Euroheat & Power with the intention to broaden the number of potential actors to develop, demonstrate and promote solar heat in district heating (and cooling) applications. A number of technologies are already applied in demonstration projects mainly in the northern parts of Europe, e.g. Sweden, Denmark, Germany and Austria. At present, there are 30 plants with > 1 400 m2 (1 MWth) solar collectors and the largest plant so far in Europe is designed with 18 000 m2 (13 MWth) solar collectors. The paper describes technology status, presents strengths, weaknesses, opportunities and threats, as well as a vision that claims that it could be feasible with close to 20 PJ solar heat in district heating systems in 2020 with a more progressive policy.