Firm Solar Power Forecast through Battery Storage and PV Overbuilding with Solar Power Curve Modeling

The decision-making of the managers of the photovoltaic (PV) plant is influenced by solar power forecasting. To mitigate errors in solar power forecasting, the firm solar power forecast strategy is proposed, the role of which is to ensure that the actual solar power fully meets the forecasted solar power. Specifically, the deviation between the actual and forecasted PV power is corrected through battery storage, PV overbuilding, and proactive curtailment. From the perspective of optimization, a mathematical model, which aims to minimize the equivalent annual cost of the PV-battery system, is formulated to implement the firm solar power forecast strategy. A case study in Heihe China is then conducted and the results indicate that the additional PV overbuilding with 1.12 MW and the installation of battery storage with a rated capacity of 2.61 MWh are required to obtain the firm solar power forecast at the lowest cost, which is 29.11% lower than that of the case where the PV plant with no overbuilding but with proactive PV curtailment and larger battery is assumed and set as a benchmark.