Economic effects of forecasting inaccuracies in the automatic frequency restoration service for the day-ahead energy and reserve scheduling of pumped storage plants

Abstract

The economic effects of forecasting inaccuracies in the automatic frequency restoration service is analyzed in the context of the operation of a closed-loop and daily-cycle pumped-storage hydropower plant. The uncertainties when scheduling the automatic frequency restoration service are composed by the residual demand curves of the day-ahead reserve market, the upward and downward energy prices due to the activation of the reserves, and the percentages of the upward and downward real-time use of the committed reserves. The plant participates in the day-ahead energy market as a price-taker and in the reserve market as a price-maker, in the context of the Iberian electricity system. In addition, the energy due to the real-time use of the committed reserves is also considered. Results show that the profit is significantly more sensitive to forecast inaccuracies of the day-ahead energy market prices than of the prices and real-time use of reserves from the automatic frequency restoration service.