Multiple operational strategies investigations of the PV/T collectors based on 3 days ahead hourly radiation prediction

The PV/T collectors are the advanced photovoltaic and photothermal integration technology, realizing full-spectrum utilization. The energy profitability of PV/T collectors not only depends on sophisticated equipment but also significantly correlates with the operational conditioning. Hybrid operational strategies are analyzed with the WOA algorithm based on 3 days ahead hourly prediction model for horizontal total solar radiation. The 3-day variable inclination strategy is unsatisfactory. The monthly cumulative radiation increases by 8 % relatively with the ground reflectivity varying from 0.4 to 0.95. And, the 5 % addition of ground reflectivity leads to an average improvement of 0.45 %. The optimal long-side and wide-side ratios of the reflector are 0.9 and 0.6 with an improvement of 8.79 % and 3.85 % in thermal and electrical gain. Compared to fixed PV/T without a reflector, the multi-hybrid strategy can achieve a relative improvement of 17.76 % and 13.61 % in thermal and electrical gain for the novel PV/T with graphite and trapezoidal fluid channels, equivalent to 39.5 MJ and 7.8 kWh with a 2.08 m2 effective area. Finally, the best model is LSTM-Attention with the R2_train and R2_test of 96.8 % and 94.0 % for 3 days ahead hourly radiation prediction. The contribution of this paper provides references on the operational optimization of PV/T collectors, especially for household rural PV/T systems.