Comparison of different solar energy utilization methods: photovoltaic systems and solar thermal power plants

This paper presents a comparison between small-scale PV systems and solar thermal power plants. The studied PV system consists of crystalline silicon solar modules and inverters. For small-scale solar thermal power plants organic Rankine-cycle was considered and four different collector types were investigated, both concentrating and non-concentrating ones. The analyses are based on a self-made model and Matlab simulation. The main comparison criteria are the electrical efficiency and the specific energy production, since these are the most important factors influencing the financial return. The possibility of the cogeneration and thermal energy storage are also assessed, since they largely influence the payback time and dispatchability of the plants. Several different geographical locations are investigated and compared, since meteorological conditions of the plant sites largely determine the amount of produced energy and the efficiency. The monthly fluctuation of energy production is also presented besides the annual aggregated values.