Manuel Chazarra

Optimal operation of variable speed pumped storage hydropower plants participating in secondary regulation reserve markets

Pumped storage hydropower plants can contribute to a better integration of intermittent renewable energy and to balance generation and demand in real time by providing rapid-response generation. In order to invest in a new pumped storage plant, it is necessary to assess carefully the profitability of the project as the recovery of investment costs could be jeopardised by many factors. Apart from participating in the day-ahead market, ancillary services can also play an important role when determining the incomes. The aim of this paper is to make a preliminary comparison of pumped storage plants market incomes with and without ability to regulate power in pumping mode through variable speed technology. A deterministic mixed-integer programming model is proposed to calculate power bids for the day-ahead and secondary regulation markets. The model considers the hourly day-ahead and secondary reserve market prices as well as usage and prices of secondary regulation-up and down energy requested by the Spanish System Operator.

Optimal Energy and Reserve Scheduling of Pumped-Storage Power Plants Considering Hydraulic Short-Circuit Operation

This paper presents a mixed-integer model for the hourly energy and reserve scheduling of a price-taker and closed-loop pumped-storage hydropower plant operating in hydraulic short-circuit mode. The plant participates in the spot market and in the secondary regulation reserve market, taking into account the regulation energy due to the real-time use of the regulation-up and -down reserves. The proposed model is used to compare the maximum theoretical income of the plant with and without considering hydraulic short-circuit operation. Numerical results demonstrate that the operation in hydraulic short-circuit mode could help significantly to enlarge the income of the power plant and that the secondary regulation reserve market might be the main source of revenue in a realistic setting characterized by a high level of renewable energy sources in the generation mix.

Economic Viability of Pumped-Storage Power Plants Equipped with Ternary Units and Considering Hydraulic Short-Circuit Operation

This paper analyses the economic viability of pumped-storage hydropower plants equipped with ternary units and considering hydraulic short-circuit operation. The analysed plant is assumed to participate in the day-ahead energy market and in the secondary regulation service of the Spanish power system. A deterministic day-ahead energy and reserve scheduling model is used to estimate the maximum theoretical income of the plant assuming perfect information of the next day prices and the residual demand curves of the secondary regulation reserve market. Results show that the pay-back periods with and without the hydraulic short-circuit operation are significantly lower than their expected lifetime and that the pay-back periods can be reduced with the inclusion of the hydraulic short-circuit operation.

Value of perfect information of spot prices in the joint energy and reserve hourly scheduling of pumped storage plants

The value of perfect information of the day-ahead energy prices is studied in the context of the operation of a closed-loop and daily-cycle pumped-storage hydropower plant, participating in the spot market as a price-taker and in the secondary regulation reserve market as a price-maker, and also considering the secondary regulation energy due to the real-time use of reserves. Results show that the percentage of the profit loss with respect the maximum theoretical income due to the errors in forecasting the spot prices in the Iberian electricity market decreases if the plant also participates in the secondary regulation service.

Economic impact of forecasting errors in residual reserve curves in the day-ahead scheduling of pumped storage plants

The economic impact of forecasting errors in the residual demand curves of the secondary regulation reserve market is analysed in the context of the operation of a closed-loop and daily-cycle pumped-storage hydropower plant. The plant participates in the day-ahead energy market as a price-taker and in the secondary regulation reserve market as a price-maker. The secondary regulation energy due to the real-time use of the committed reserves is also considered in the optimization model. The results show that profit is significantly more sensitive to forecast errors in the day-ahead energy market prices than in the residual demand curves of the secondary regulation reserve market.