Utility-scale storage providing peak power to displace on-island diesel generation

Abstract Peaking power plants are used to provide power during periods that have both high load and limited supply from intermittent renewable energy. Wind power is intermittent and does not always provide electricity during periods of maximum demand. Despite this, it has grown to produce a significant portion of the electricity in some jurisdictions. Electricity systems require firm capacity that operate when called upon. Fossil fuel peaking plants are costly, providing a fraction of the annual energy at a great cost, but ensure system reliability. Utilizing storage systems to provide these services during peak times could allow integration of higher penetrations of renewable energies. Prince Edward Island, Canada has over 40% of its load produced by wind power but requires diesel generators during high load and low wind periods. The diesel generators ensure that the submarine cables are not overloaded and provide on-island power during other curtailments. The 1 MW/2 MWh storage system provided energy and capacity from December 2015 to March 2016 and was paid for these services by their local utility. The payment only covered 9% of the costs due to the high capital cost and short life expectancy of their storage system.