Projection of future daily global horizontal irradiance under four RCP scenarios: An assessment through newly developed temperature and rainfall-based empirical model

Abstract Demand for solar energy is increasing due to its clean nature in contrast to conventional fossil fuel sources and lowering of the cost harvesting solar energy. Consequently, it’s important to assess the spatio-temporal distribution and future projection of global horizontal irradiance (GHI) under future climate scenarios. However, due to the absence of high-quality ground observations, whether related to the measuring site accessibility or the associated high cost of equipment, it’s generally difficult to get GHI at the desired spatial interval. Empirical calibrated models may be used for estimating GHI using other local meteorological parameters available at finer spatial interval. The present study compared the performance of four popular empirical models including a newly proposed MND model with an intention to reduce model complexity. The models are calibrated and validated over nineteen locations spread over four climatic zones of India. The results reveal that the MND model performs more efficiently than the other three models. Statistical parameters also confirm the accuracy level of MND. Four sets of common coefficients are generated for projection of daily GHI in any location of the respective four zones. Finally, temperature and rainfall data sets projected by the CMIP5 models, corresponding to 23 locations across the West Bengal State, are used to produce GHI for four future periods under four Representative Concentration Pathway scenarios. Simulated results support the view of having less GHI availability in the near future. In general, the whole State might experience a deficit in annual mean daily GHI by ≥1 MJ m-2day−1.