Enormous quantities of generation will need to be curtailed and thus wasted.

New forms of storage and demand-response will help the system to absorb surpluses in variable renewable generation without resorting to curtailment.

Curtailment happens when there is more wind or solar output than the system can absorb, either due to insufficient demand or insufficient transmission capacity. By enabling local demand to take advantage of this oversupply, storage technologies (like batteries) and demand response technologies (like the smart charging of EVs), help to ensure that this power has somewhere useful to go and thereby limit the need for curtailment.

Reinforcement of the power grid can also help ensure that this power can reach those that can use it. The planned north-south transmission infrastructure in Germany is expected to transport wind from the wind-rich north to the demand centres in the south. These grid upgrades are expected to profoundly reduce the costs associated with curtailment. An alternative to new transmission, if the former is not viable from an economic or public acceptance perspective, is to build renewable generation at sites closer to consumption in order to reduce the need for grid expansion. Such a measure can be supported through appropriate policy and decentralised power market design.


CAISO, “Managing Oversupply-Solutions,” 2017, http://www.caiso.com/Documents/ManagingOversupply-Solutions.pdf.

Xiaohe Yan et al., “Power to Gas: Addressing Renewable Curtailment by Converting to Hydrogen,” Frontiers in Energy 12, no. 4 (2018): 560–68, https://doi.org/10.1007/s11708-018-0588-5.

Jennie Jorgensen, Trieu Mai, and Greg Brinkman, “Reducing Wind Curtailment through Transmission Expansion in a Wind Vision Future,” no. January (2017): 38, https://www.nrel.gov/docs/fy17osti/67240.pdf.

Agora Energiewende, “Cost Optimal Expansion of Renewables in Germany,” 2013.

Michael Joos and Iain Staffell, “Short-Term Integration Costs of Variable Renewable Energy: Wind Curtailment and Balancing in Britain and Germany,” Renewable and Sustainable Energy Reviews 86, no. February 2017 (2018): 45–65, https://doi.org/10.1016/j.rser.2018.01.009.

Felix Böing, Andreas Bruckmeier, Timo Kern, Alexander Murmann, Christoph Pellinger, “Reliving the German Transmission Grid with Regulated Wind Power Development,” 2017, 1–15.