FAQs

The SDH projects make available a Find Professionals Tool in Europe.

The SDHTO project makes available:

• analysis of built examples and of market conditions (WP2)
• a deep technical and regulation document (WP3)
• set of training slides (WP4)
• training courses in different countries
• workshop and meetings for experts

These can be downloaded at:
www.solar-district-heating.eu/Documents.aspx

Yes, the ST plant is very flexible and examples exist of combination with biomass, natural gas and CHP plants.

Investment costs of the system can be different from case to case. Cost of the collector array depends on the several conditions e.g. location, size of the system (ranging between 600 and 200 € per m²) and can be related to the solar heat gains in kWh per m².
Quotient of these values multiplied with an annuity factor gives the cost of the solar heat (Example: 300 €/m² and 400 kWh/m² and annuity factor 0.08 gives a price 0.06 €/kWh) Cost of the heat storage varies depending on the system design from very low if the collector array is connected directly to the district heating network without storage to about doubling the investment cost in € per m² when long term storage is used. An online calculation tool is available for free at:
www.solarkey.dk/f-easy/f-easy.xlsx

See question 5. The solar collectors can be installed either on the ground or on the roofs. For ground mounted collectors it takes normally 3-4 m² of land per m² collector installed to minimize shading.

The main part of the operating costs is connected to the electricity consumption and maintenance. These costs are about 1 € per MWh of produced heat. It is also necessary to consider insurance costs.

A seasonal storage has been used in several existing SDH plants to exploit this opportunity.

It depends on several boundary conditions e.g. locality, designed solar heat share on the annual heat production, operating temperature (the lower, the better), accumulation capacity of storage and system etc. Systems with solar heat share up to 30 % have usually annual specific gains between 400 and 500 kWh/m².

Certified ST collectors undergo a standard test procedure for evaluating their yield as well as their durability, reliability and safety easures. The EN 12975-1 and 2 and the CEN/TS 12977-1 and 2 are the reference standards.

Proven durability of solar collectors is between 20 and 30 years, without significant loss in terms of performance. This corresponds to the expected life of the SDH systems even though there are parts that have to be replaced earlier such as pumps or a collector fluid.