An optimised hybrid biomass combined cycle with integrated solar thermal system

Abstract

In recent years, renewable sources of energy have become an encouraging solution to the environmental and availability problems arising from using fossil fuels for power generation. In the present study, solar and biomass (sawdust) are incorporated into large-scale gas and steam turbines to form a resourceful and efficient system. Furthermore, two hybrid configurations (fuel economy and energy boosting modes) of the proposed combined system are modelled using the Cycle Tempo software. The system’s performances reveal that at 9 bar inlet pressure, the net power, energy and exergy efficiencies generated in the fuel economy mode (49 MWe, 61%, and 55%) and energy boosting mode (51 MWe, 64% and 57%) are significantly higher than those obtained in the standard biomass combined cycle system without solar fields (28 MWe, 35% and 31%). Moreover, the addition of solar energy brings about an increment of around 21 MWe in the fuel economy mode and 23 MWe in the energy boosting mode. The exergy transmitted from the fuel economy and energy boosting modes also yields greater GT combustor efficiency (89%) than the standard mode (79%). The proposed hybrid system through the incorporated clean energy offers better performance and could serve as an alternative to existing fossil fuel plants.