Numerical simulation and assessment of a 5 MWel hybrid system with a parabolic trough once-through steam generator coupled to biomass gasification

Concentrated Solar Power (CSP) has proven to be a reliable and economical solution due to the easiness to dispatch energy with thermal energy storage (TES) integration. On the other hand, valuable concepts such as Direct Steam Generation (DSG) have been hindered by latent heat storage technical challenges. An interesting concept is renewable energy hybridisation. It consists in the strategic combination of different renewable sources in the power generation portfolio by taking advantage of each technology. For example, DSG hybridisation with biomass gasification can be a reliable solution to improve DSG dispatchability and overcome technical issues, which was assessed in this paper. For the purpose, a 5MWel hybrid CSP/biomass gasification plant operation is assessed through numerical simulation, using a model validated against experimental tests carried out at Plataforma Solar de Almeria (for the solar field) and at the University of Porto (for gasification). The hybrid plant performance is assessed under start-up, steady and transient solar radiation. Results show hybridisation advantages, such as: an improved solar field start-up and assuring electricity generation; absence of power shortages during transient solar radiation and faster recovery from part load; stable power generation with a rather low solar multiple (about 1) and low biomass share. In summary, results show that DSG/biomass gasification hybridisation is an interesting solution to improve a DSG plant overall performance and to overcome operational limits, and thus a breakthrough concept to enhance commercial deployment.