Study on the local climatic effects of large photovoltaic solar farms in desert areas

Large-scale solar power plants are rapidly increasing in size and number across the world. However, the surface heat balance is altered when a photovoltaic (PV) power plant is operating. Modifications to the surface albedo through the deployment of photovoltaic arrays have the potential to change radiative forcing, surface temperatures and local weather patterns. In this work, the field observation data from a large solar farm and a region without PV array in Golmud are used to study the impact of large solar farms in desert areas on the local meteorology. The results show that the total daily values of upward shortwave radiation and net radiation in the two sites are significantly different. The mean daily albedo in the solar farm is 0.19, while it is 0.26 in the region without PV. The annual mean net radiation in the solar farm is evidently higher than that of the region without PV. The daily range of soil temperatures at a depth of 5-10 cm in the solar farm is lower than that in the region without a PV farm. The annual range of soil temperatures at a depth of 5-180 cm in the solar farm is higher than that in the region without PV. The soil temperatures at different depths in winter in the solar farm are clearly lower than those in the region without PV. The daily mean of soil temperatures at a depth of 5-80 cm from October 2012 to March 2013 is clearly lower than that in the region without a PV array. The 2-m daytime air temperature in the two sites is essentially the same during winter, while during the other seasons, the daytime air temperature in the PV farm is higher than that in the region without PV, with the maximum difference appearing during the summer. The nighttime air temperatures at a height of 2 m during the four seasons in the solar farm are higher than those in the region without PV. The monthly average 2-m air temperature in the solar farm is higher than that in the region without PV.