In the context of European legislation in favor of increasing the share of renewable energy in energy supply, the use of solar thermal in district heating gradually emerges. Already implemented in some leading countries (Denmark, Sweden, Austria and Germany), the coupling seems promising. It should be remembered what is a district heating: it consists of a central heating system and a network of underground isolated pipes that connect al the sub-stations (users) typically equipped with a heat exchanger. A kind of a Smart Grid in which solar thermal can bring all its technological and environmental value!

Within the framework of the call 'Appel à manifestation d’intérêt' of ADEME, a group coordinated by Clipsol (manufacturer of flat plate solar collector) and the partners SAED (manufacturer of vacuum tube collectors), COFELY GDF SUEZ (District heating operator),CEA INES (Solar Energy Research Center), INDDIGO (Sustainable Development Engineering office) and TECSOL (Solar Engineering office) edited the project 'Smart Grid Solaire Thermique' that will address the integration of solar thermal in district heating networks. The project has been selected and began on 1 July 2012. It is supported by ADEME through the Program of Renewable Energy Investments for the Future.

The goal is to initiate a new way of use for solar thermal energy in France, and to approach a little more the ambitious objectives of the Grenelle Environment. Challenges for the team are:

• the development of solutions for district heating in France, and specially in south
• the development of solar collectors adapted to district heating
• the study of long-term storage solutions for solar thermal
• the creation of technical and financial engineering services specialized in integration of solar heat in district heating
• the development  of specific services for solar district heating operators

Over a period of five and a half years, this project will lead to improve the share of renewable energy in the energy mix of district heating, but also to improve the competitiveness of solar thermal in France and to reduce the price of solar energy.