Japanese Research Institute, Start-up to Begin Testing Solar Thermal Cogeneration System

Copyright RIKEN

RIKEN, Japan's comprehensive research organization for basic and applied science, and Da Vinci Co., specializing in heat utilization, announced on January 10, 2013, that they have designed a cogeneration system that efficiently captures solar thermal energy for power generation and hot water supply. They plan to introduce a 1-kilowatt prototype in 2013 and conduct demonstration testing using a 10-kilowatt system in 2014.

The system, which consists of panel-type Fresnel lenses developed by RIKEN arranged three-dimensionally with a top and two sides (east side and west side), is capable of capturing solar thermal energy from all directions from sunrise to sunset without a solar tracking device. Collected thermal energy is stored in a thermal storage tank as warm water by heating water with a heat exchanger.

When the warm water is supplied to a rotary heat engine (RHE) developed by Da Vinci, the engine generates electricity, allowing the stored thermal energy to be extracted for power generation, while and hot water itself can be supplied for other usages on demand. The RHE features excellent thermal efficiency even at the low pressures generated by low water temperatures, extracting rotational energy from water as low as 40 degrees Celsius.

The system can generate electricity for 24 hours a day when factory waste heat is combined and also has excellent scalability. Working with local governments, RIKEN and Da Vinci hope to promote more effective use of solar thermal and a more distributed power supply, and are also planning to build a pilot plant.