Floating Photovoltaic for the Coal Mining Subsidence Water Area—an Effective Way to Reduce Evaporation

Floating Photovoltaic (FPV) is an innovative technology to deal with the current energy and land crisis, while effectively reducing evaporation. Taking the 150 MW FPV power station in Huainan City, Anhui Province, China as an example, this study aims to calculate evaporation rate under FPV coverage and evaluate the Water-Saving (WS) potential of FPV through empirical monitoring and model calculation. The results show that the modified Penman-Monteith (PM) model can basically characterize the actual evaporation process under FPV coverage, and the annual average evaporation suppression efficiency is about 58%. Covering an area of 2.84 km
²
, the FPV power station saves about 1,948,067 m
³
of water annually. Considering the 25year life cycle, the total WS can reach 48,701,668 m
³
. If the WS is effectively utilized, it can meet 3.8% of the annual ecological environmental water consumption in Huainan City. Selling of water resources can also obtain additional economic benefits and make significant contributions to local water supply and agricultural irrigation.