Market evaluation of hybrid wind-storage power systems in case of balancing responsibilities

This study investigates the economics of a wind power farm with a long-term market perspective, considering high shares of wind energy, constraints set on the energy variability, and the removal of support schemes such as feed-in tariffs. The contractual agreement with a compressed air energy storage facility (CAES) would create a hybrid wind-storage system that would allow a wind power operator to reduce the intermittency of its output and to provide flexibility to the system. The study gives a market value to the wind power at a project level of several gigawatts capacity located in France, by using a technical and economic optimization model. Results indicate the cost of balancing the intermittency for the wind operator and show that under baseline conditions, the hybrid wind-storage system would have negative profits despite price arbitrage operations and ancillary services provided to the system. Alternative tests show that the economics can improve when the influence of the wind power on the spot price is accounted for. The study is focused on the long term market situation in France, which is characterized by increased balancing needs, an ageing infrastructure, uncertainties in carbon and gas prices, and increased power imports.