Techno-economic assessment of soiling losses in CSP and PV solar power plants: A case study for the semi-arid climate of Morocco

Many sites suitable for photovoltaic (PV), concentrated solar power (CSP) or hybrid CSP/PV plants are located in the desert or arid and semi-arid areas, where they can suffer from soiling accumulation on the surfaces of solar collectors. The aim of this research is to assess the impact of soiling on the annual performance of CSP and PV solar power plants from a technical and economic perspective. The yield analysis of 1MWe linear Fresnel CSP and 1MWe PV solar power plant is performed under the semi-arid climate of Morocco. One year of ground-based and quality-checked meteorological data, as well as one year of soiling data collected from two soiling monitoring sensors (a Tracking Cleanliness Sensor (TraCS) and a DustIQ) are considered in the analysis. The optical soiling loss is 5 to 6 times higher in case of CSP compared to PV, with an annual average daily of 1.21 %/day and 0.24 %/day, respectively. The total annual energy loss due to soiling, considering a monthly cleaning frequency, is equivalent to 17.76 % and 1.95 % for CSP and PV, respectively. The energy loss depends not only on the optical efficiency drop due to soiling, but also on the available solar resources at the location. The LCoE increases significantly if the impact of soiling is accounted, especially for CSP technology. The analysis of the different cleaning profiles reveals that the cleaning frequency of 3 weeks gives the highest profitability for both PV and CSP solar plants.