Design and simulation of a novel hybrid solar-biomass energy supply system in northwest China

Making full use of solar energy and biomass to supply clean energy for buildings can effectively reduce environmental pollution and optimize the energy industry structure. This research designed a novel hybrid solar-biomass energy supply system and evaluated its thermodynamic performance as well as its practical feasibility. The system mainly consists of a solar subsystem and a biomass subsystem and is used to supply heat energy for the anaerobic reactors and a nearby building. The daily excess biogas is used to provide cooking fuel to the surrounding households. The results indicate that the average annual energy efficiency and primary energy saving rate of the system are 25.18% and 94.98% respectively, and the carbon emissions reduction is about 2961.85 (tons/year). Compared with the reference systems, the system has obvious advantages in energy conservation and carbon emissions reduction. The sensitivity analysis shows that the increase of the area of the solar collector and the insulation thickness of the anaerobic reactors can obviously improve the energy efficiency of the system, while the energy efficiency of the biogas boiler gets worse. In addition, the proposed system has a good profitability with a payback period of 5.15 years. By optimizing the configuration, the life cycle cost of the system is reduced by 9.7% while the energy efficiency increases by 1.1%. Such a system is attractive, especially for rural areas in northwest China where the economic development is relatively slow, but the solar and biomass resources are quite abundant. (C) 2019 Elsevier Ltd. All rights reserved.