SunOyster Systems delivers solar power plants with an efficiency of 75 percent

SHUZHOU, CHINA: SunOyster Systems GmbH (SOS), manufacturer and developer of the concentrating solar technology SunOyster, signed a supply agreement with the Yonghao Gangue Power Plant Ltd for the delivery of 63 concentrator systems in the Chinese province of Shanxi.

The bi-axially tracking systems, the "SunOyster 16", concentrate sunlight through semi-parabolic mirrors onto a linear-shaped receiver and achieve an energy-based total efficiency of up to 75 percent.

In the spring of this year, SunOyster Systems will first deliver 13 plants of the SunOyster zero series to supply energy to Chinese apartment houses. The hybrid receivers will initially generate electricity by means of solar cells. Since the cells are actively cooled by a heat transfer fluid, the receiver will also co-generate heat, which can be used to heat space, water as well as to drive refrigerating machines.

For this first part of the demonstration project, SunOyster Systems will be installing high quality back-contact silicon cells that have an electrical system efficiency of 15 percent. Their thermal efficiency amounts to 60 percent. They can only be operated, however, at transfer fluid temperatures of up to 100° Celsius.

For the second batch from the pre-series of the SunOyster systems, receivers with concentrator cells shall be used. They achieve an electrical system efficiency of up to 30 per cent and can be operated at transfer fluid temperatures of up to 200° Celsius, which expands their range of use. The mirrors of the concentrator systems have a surface area of 16 square metres and reach 5 kW of electric and 7.5 kW of thermal power.

Whereas the electricity generated by the concentrator cells is directly fed into the grid, the operator Yonghao Gangue Power Plant will use the co-generated heat to pre-heat feed water for the operation of a coal-fired power plant. Since this heat, with an efficiency of 10 per cent, contributes to additional electricity generation, the overall system's total electrical efficiency is 40 percent.