Blogging is online. Hence online resources are rather streight forward to point at. However, Googling turns out to show a lack of knowledge within this topic: Central Solar Heating Plants (CSHP) or Large-Scale Solar Heating. As a researcher, library information are traditionally the main source for information. Therefore I tried to search in our library including more than 45,000 journal articles. The hit rate for is 22 hits that matches the full term “Central Solar Heating Plants”; “Central Solar Heating” gives 82 hits, below 10 hits unique and written after 2000, the newest from 2004, most much older.
Can we conclude that Central (large scale) Solar Heating is not relevant?
We can cerainly conclude that the topic is not “hot”. Is this because there is no research going on, is it because the research is not pulished or is not accepted for publishing? This question is keept open.
Is the topic relevant?
Positiv aspects of CSHP: From the experiences from Marstal and most other plants, one can conclude that the efficiency for large-scale systems is much highere, compared to small solar systems. The installation price is appoximatelly 60% of the installation price for small systems. The price-performance is hereby better for both price and performance. Details can be found in the Ph.D. citet earier in the blog by me. Maintenance, effieciency improvements and other aspects do also point at large installations.
Problematic aspects of CSHP: However, heat losses can be relativelly large, if one does not consider it appropriatelly. Modells to do that can be found, among others, in “Heat-load modelling for large systems”, Applied Energy, p. 371-387, 72(1), 2002. Another negative aspect of large scale solar heating comes up, when combining solar heating with co-production power plants, where the “waste” heat is applied in district heating. This is the case for the Copenhagen District Heating, where an area with up to 30 km in wide, supplied with district heating. The problem here is, that the heat exaustion by power production does make the replacement with solar problematic, as long as the overall efficiency of the power production and “waste heat” are related.
So, the question must be answered, that the topic is very relvant for any large-scale heating system. Solar cooling could be combined, improving the efficiency even more. If you are researchers and look for an important research topic, here it is. District Heating & Cooling supported by Solar Energy with and without long-term heat and cool storage. As you find in this blog, there is a lot to work with.