Concentrated solar thermalProject Advanced Steam-Generating Receivers
A report on testing solar thermal technology steam generation for use in large scale Concentrating Solar thermal Power (CSP) stations.
The project is a detailed investigation into steam generation using solar thermal technology. High pressure and temperature steam drive the majority of the world’s electricity producing turbines and the development of technology suitable for implementation into solar thermal systems is critical to the continued uptake of concentrating solar thermal power technology.
This project achieved steam conditions comparable to state-of-the-art fossil-fuelled power stations, using large scale Concentrating Solar thermal Power (CSP) stations, something that has not been achieved in all other commercial CSP plants in the world today. This represents a world record for the combined temperature and pressure of steam using solar thermal technology.
The project successfully demonstrated that significant reductions in the capital costs of the system can be achieved through higher thermal efficiencies and a resulting reduction in the total area of the solar collector required.
At the time of project conception, commercial concentrating solar-based steam power systems had a thermal efficiency below 30% (in the conversion of solar energy to electricity). Using steam at higher temperatures and pressures increases the thermal efficiency, meaning that for the same amount of collected solar energy you can produce more electricity. Typical subcritical power stations have thermal efficiencies of approximately 35%, while supercritical power cycles can have thermal efficiencies above 40%. This means that if a concentrating solar thermal power station could operate with supercritical steam the electricity output could be boosted by 20-30%, providing a substantial increase in sellable electricity for the same capital investment, resulting in a significant reduction in Levelised Cost of Energy (LCOE) against the current concentrating solar power stations.
This work also showed that geothermal sources were unsuitable for use in a steam power system designed to operate at the temperatures and pressure comparable to traditional fossil fuelled power stations, due to the low pressure of the steam able to be generated. Hybridising with other solar technologies was also examined; these showed more promise with estimated LCOE values of between 20-25c/kWh.