The CSP2 project puts forward an alternative heat transfer fluid (HTF) for concentrating solar power (CSP) plants. We propose to use dense gas-particle suspensions -DPS- (approximately 50% of solid) in tubes as HTF; these tubes set in a bundle constitute the solar absorber (receiver), placed at the top of a central receiver CSP system. This new HTF behaves like a liquid although it permits to extend working temperatures at temperature higher than 550°C; moreover, it may be used as an energy storage medium because of its good thermal capacity. It is composed of any particulate mineral standing high temperature, thus deeply reducing the environmental impact and addressing the safety concern in comparison with standard HTF. Finally, it can be easily produced in high quantities without any chemical process development.

Eight partners with complementary capabilities will work together in order to reach the project goals. They are 5 top-ranked public research organisations and universities and 3 private companies (including 2 SMEs), well established and specialized in electricity production from concentrated solar energy, high temperature gas-solid reactors, and solid handling, respectively.

In the frame of the project, a 100-150 kWth pilot loop will be designed, constructed and tested at the focus of the CNRS solar furnace in Odeillo, France. The main target for the innovative solar receiver is to deliver hot DSP in the temperature range 500°C-750°C for solid mass flow rate varying from 1 to 2 tons/h with a 70% thermal efficiency.

Finally, the global system will be analyzed and scale-up will be proposed toward industrial CSP facilities (10-50 MWe). Economic assessment will allow comparing this new technology to the molten salt one.

Artist's view of the solar pilot rig