Economic and financial benefits for wind turbines providing frequency response exploiting the kinetic energy or operating part-loaded

This work assesses the financial viability of a wind farm project where wind turbines are equipped to provide frequency response services. Two control strategies are compared: the former enables the frequency response provision by operating the wind turbines part loaded, the latter would instead employ the kinetic energy stored in the rotating masses of the turbines. The analysis also accounts for typical factors affecting the wind farm operation e.g. the wake effect and the forecast errors on wind availability. A two-stage optimisation model determines the day-ahead and (close to) real time operation of the turbines, which profit from selling energy at the wholesale energy market (and associated subsidies), receiving availability payments for frequency services, while facing imbalance costs due to mismatches between forecasted and available wind values. The two control strategies are applied to the Teesside Offshore Wind Farm and the resulting economic and financial performance are evaluated against a base case where the wind farm does not provide any frequency response service. Under current settings, the added value from frequency response capability is marginal. Changes to the market value of frequency response services would favour the strategy based on part-load operation of the turbines. The scheme based on the deployment of kinetic energy becomes profitable mainly when the duration of time window for frequency response reduces.