PREESC project - Wind Energy Reserve Potential in Crisis Situations. Final report, February 2023

Due to the application of noise and bat curtailment strategies, a significant number of wind farms do not exploit all of their production capacity. In a context of tensions in terms of energetic supply for the country, power gains associated to the removal of these curtailment strategies were estimated in this study. These potential power gains were estimated by modelling time series of hourly production data on 110 operating wind farms, representing 678 wind turbines and 1.5 GW of installed capacity. An analysis of the representativity of this sample compared to a larger sample of about 1/3 of the total wind power capacity installed in France, was carried out. It results that the main sample can be considered as representative of the French wind farms in terms of proportion of wind farms concerned by the application of an acoustic curtailment strategy. However, the main sample should underestimate in a significant manner the part of wind farms concerned by bat curtailment strategies. The impact on production of the noise curtailment strategies was estimated at 2.1 % while the impact of the bat curtailments was estimated below 0.5 % (estimation taking into account the lack of representativity of our sample). The modelling of potential production gains over year 2021 indicates that the removal of noise curtailment strategies would have led to a gain slightly higher than 700 GWh. During nighttime, when this curtailment is most present, the removal of this curtailment strategy would have led to average power gains higher than 270 MW on winter periods, which represents 30 % of the power of the most common French nuclear reactors. Power gains of 600 to 700 MW can also be reached on windy hours. This analysis also indicates that the removal of noise curtailment strategies is not a solution to fill the lack of electricity during the consumption peaks. It is up to the national network operator to appreciate if in a context of uncertainty in terms of energy supply, this significant 'energetic stock' can be relevant outside of the consumption peaks. Is should also be noted that the predictability of these potential production gains 24 to 48 h in advance should allow the network operator to manage in a satisfactory manner this 'energetic stock' when it is available. The environmental study carried out in this report indicates that a punctual removal of the noise curtailment strategies (limited in time) could be acceptable by people living close to wind farms contrary to a generalized or a softening of the curtailment strategy which would require case-by-case modellings (diversity of the situations). Concerning the bat curtailment strategies, the low levels of power gains obtainable by removing this curtailment strategy in regards to the environmental issues of protecting the biodiversity, could lead to consider that removing this strategy is not a relevant option. That being said, in order to balance the network, the risks of power cuts should help with the acceptance of the removal of these curtailment strategies, if they remain punctual. It should also be noted that beyond these considerations, this study does not presume in the legal and technical feasibility to remove rapidly and on a large scale these curtailment strategies. (authors)