Imagine a small power station that runs on sunlight, stores heat like a thermos, and keeps generating electricity even after the sun goes down — all without needing water for cooling. POLYPHEM built exactly that: a 60 kW system that combines two engines in a clever way to squeeze 18% efficiency out of concentrated sunlight, with enough stored heat (2 MWh) to keep running through cloudy spells. Think of it as a self-contained power box for places too small for a big solar farm but too remote for the grid. It could also be adapted for desalination or heating buildings.
Remote communities, islands, and small industrial sites in sunny regions depend on expensive diesel generators or unreliable grid connections for power. Large-scale concentrated solar power plants require massive investment and are designed for utility-scale output, leaving smaller users without a viable solar thermal option. These same locations often face water scarcity, ruling out conventional CSP that needs water for cooling.
A complete 60 kW prototype solar power plant combining a solar-driven micro gas-turbine with an Organic Rankine Cycle, plus a 2 MWh thermal energy storage unit. Nine physical demo deliverables were manufactured and installed: solar receiver, gas turbine enclosure, power block, thermal storage, ORC module, PLC control board, recovery heat exchanger, interconnection tubing, and auxiliary piping/cabling.
If you are an energy provider serving remote communities or islands dealing with expensive diesel generation and unreliable grid connections — this project developed a 60 kW solar combined-cycle plant with 2 MWh thermal storage that needs no water for cooling. The target electricity cost of 21 c€/kWh and investment below 5 €/W could directly replace diesel generators in sunny regions.
If you are a desalination operator in a coastal arid region dealing with high energy costs for freshwater production — this project built a self-contained solar power system validated at TRL 5 that explicitly targets water desalination as a future application. The system requires no cooling water itself, making it ideal for water-scarce locations where every drop counts.
If you are a facility manager at a small factory or processing plant dealing with rising energy costs in Southern Europe or North Africa — this project demonstrated a combined heat and power solar system with 18% conversion efficiency and thermal storage at 28 €/kWh. The system can provide both electricity and heating/cooling for multi-family buildings or small industrial sites.
The project targets an investment cost below 5 €/W for the complete system. The solar receiver component alone targets 0.4 €/W, and the thermal storage targets 28 €/kWh. For the 60 kW system demonstrated, that implies a total system cost target under €300,000.
The prototype was validated at 60 kW with a 2 MWh thermal storage unit at TRL 5 (tested in relevant environment). The project established guidelines for commercial deployment, but scaling up would require further engineering and validation. The design is specifically aimed at small-scale applications, not utility-scale.
Key technology — the pressurized air solar receiver with 80% efficiency — is based on patents held by CEA and CNRS. The consortium of 10 partners across 4 countries (DE, DK, ES, FR) includes 5 industrial partners, so licensing arrangements would need to be negotiated with the coordinator CNRS and relevant patent holders.
The project targets 21 c€/kWh under solar irradiation of 2050 kWh/m2/year, which meets the EU SET Plan target of 40% cost reduction for small-scale CSP. This is competitive with diesel generation in off-grid locations but above grid prices in most connected European markets.
No. The project explicitly states there is no water requirement for cooling, which is a major advantage over conventional CSP plants. This makes it suitable for arid and water-scarce regions where traditional power plants face restrictions.
The project built and validated a complete 60 kW prototype in a relevant environment, achieving TRL 5. Nine physical deliverables were completed including the solar receiver, gas turbine, thermal storage, ORC module, and control systems. Commercial deployment would require further piloting at TRL 6-7.
Based on available project data, the system was designed to meet EU SET Plan targets for small-scale CSP cost reduction. Specific grid-connection standards and local building codes would apply depending on the deployment location. The RIA funding scheme means this was a research project, not yet a market product.
POLYPHEM brings together 10 partners from 4 countries (Germany, Denmark, Spain, France), coordinated by CNRS, France's largest public research organization. The consortium has a strong commercial orientation with 50% industry participation (5 companies including 4 SMEs), balanced by 4 research centers and 1 university. This mix means the technology was developed with industrial manufacturing and cost targets in mind from the start — not just lab curiosity. The 4 SMEs suggest the supply chain for components like the solar receiver and thermal storage is already forming around smaller, specialized manufacturers rather than depending on a single large corporation.
CNRS (Centre National de la Recherche Scientifique), France — coordinator of the 10-partner consortium
Want to explore licensing this small-scale CSP technology or connecting with the POLYPHEM team? SciTransfer can arrange a direct introduction to the right people in the consortium.
