Day-ahead trading of wind-battery hybrid power plants: Wind forecast uncertainty and limited feed-in grid connection

This paper investigates the optimal operation of a wind-battery hybrid power plant. The analysis focuses on quantifying the economic difference between trading a wind power plant and a battery storage individually in the day-ahead market, or trading the wind power plant only and using the battery to minimize wind imbalance volumes. In addition, considering a limited feed-in grid connection capacity, a comparison between deterministic and stochastic optimization models to include wind forecast uncertainty is assessed, aiming at minimizing wind power curtailment. For the analysis, wind power plant and battery storage sizes are fixed at 1.3 GW and 300 MW/600 MWh, respectively. The investigation considers historical energy forecast and production data of an offshore wind power plant.
On the one hand, the economic comparison suggests that bidding both wind power plant and battery storage individually in the day-ahead market has higher profitability than using the battery to minimize imbalance volumes only. In fact, by using the battery to cover wind energy imbalances, the overall wind-battery plant profit decreases by 2.37%, even though the imbalances are reduced by 35.6%. On the other hand, including the uncertainty of wind energy production in the stochastic model, the optimized battery operations reduce the curtailed wind energy by 35%