Last week I wrote about large solar thermal roofs, often over 100m2 ( square meters ), and occasionally over 1,000m2 designed by innovative companies such as SOLID solar. Today I want to write about the same technology, but where they are ground mounted instead of roof mounted, and where the collector area is currently up to 15,000m2 and soon projects of 35,000m2 will be built. If Austria is the world leader in the roof mounted category then Denmark is in the ground mounted category. The map of Denmark above shows currently operating plants and those planned, and the photo is of the system at Marstal, one of the first, and soon to be doubled in size.
As mentioned last week the larger the storage capacity and the better the insulation the more useful the system will be in terms of storing summer solar gain to meet maximum winter heating demand. Last week I noted that Gneis Moos had a thermal store of 100,000 litres, which is 100 cubic meters (m3). The 35,000m2 solar collector at Dronninglund will have a thermal store of 60,000m3, which to give one a sense of scale is 24 times the size of an Olympic swimming pool, or 600 times the size of that at Gneis Moos.
In the last few years these types of large scale solar district heating systems, increasingly integrated with other forms of renewable energy, are becoming more common in Denmark, and as the unit cost is falling and gas and other fossil fuel prices are rising, they will become increasingly common. There is a very interesting document on the Danish experience here http://www.solarthermalworld.org/files/Solar%20District%20Denmark.pdf?download (.pdf, 3.2Mb)
Who will build the first one in the UK?