Evaluation of solar aided biomass power generation systems with parabolic trough field

Abstract

Solar and biomass are both renewable energy resources. Using biomass as fuel is becoming more and more attractive after governments increase the tariff for the electricity from the renewable sources. However the costs of power from a biomass power generation plant depend greatly on the availability and quality of the biomass resource. The commercialization of solar alone thermal power generation is hindered by its high initial investment and low thermal efficiency. In this paper, a concept of integrating solar into a biomass power generation system is put forward. In the system the oil heated by a parabolic trough solar field is used to replace the extraction steam to preheat the feed water (entering a biomass boiler) and the previous extraction steam thus saved can continue to do work in the lower stages of turbine. The performance of the hybrid system with different replacements is analyzed and compared through two typical solar aided biomass generating units. The results show that the integration not only reduces the consumption of biomass fuel (at the same generation capacity) but is also proved to be an efficient way to convert solar thermal energy into power. The results also show that with the same solar aperture area, the higher the grade of the replaced extraction steam, the better the thermal performance and economy.