China’s Ministry of Housing and Urban-Rural Development (MOHURD) this weekend released a draft standards proposal for grid-connected wind and solar + storage plant design where storage is installed in conjunction with either wind, solar, or wind-solar hybrid plants. The proposed standards would apply to all new construction, expansions, and renovations to wind and solar generating assets rated at 10 MW and above designed with accompanying electrochemical storage equipment. The standards do not require all wind, solar, and wind-solar hybrid plants to include storage, but instead guide the design of facilities constructed with storage in mind.
The standards, based from the results of various optimization tests, make the following recommendations based on the principal application of the storage resources.
- Output smoothing mode: for storage assets used to correct for sharp fluctuations in wind and/or solar output. Installed storage should be no less than 10% of generation power with discharge capacity no less than 0.5 hours.
- Output tracking mode: for storage assets used to aid wind and/or solar plants meet the power dispatch commitments. Installed storage should be no less than 30% of generating power with discharge capacity no less than 1 hour.
- Frequency regulation mode: to regulate generation output frequency. Installed storage should be no less than 20% of power generation rating. No discharge time standard provided.
- Peak shaving/valley filling mode: further recommendations will be made based on grid needs.
Comments for the proposed standards are requested to be submitted before July 28, 2017. It is not yet clear whether the proposed standards will be legally binding are provided instead as design guidelines.
Australia, meanwhile, after recently announcing plans for a 129 MWh Li-ion battery system as part of a wind farm in South Australia, is considering similar standards for renewable generation-sited energy storage. Minister for the Environment and Energy, Josh Frydenberg, recently proposed a “generator reliability obligation” suggesting 25% capacity and 4 hours of storage as guideline, conceding the exact figure would ultimately be up to the Australian energy market operator, AEMO.