LAES operates by using excess electrical energy to drive an air liquefier. The liquid air is stored in an insulated tank at low pressure, which functions as the energy store. When power is required, liquid air is drawn from the tank and pumped to high pressure. Ambient heat is applied to the liquid air via heat exchangers resulting in a phase change from liquid air to a high pressure gas which is then used to drive a turbine and generator.
Gareth Brett, chief executive at Highview – the firm responsible for the design, build and testing of the LAES plant along with project partners Viridor, said that it will be an “invaluable demonstration” for the power sector to “evaluate, implement, utilise and capitalise” on LAES.
The project, which broke ground in February 2015, has now received delivery of the main equipment at the Pilsworth site, including the turbine and generator from GE, heat exchangers from Heatric, thermal storage tanks from Metalcraft and cryogenic storage tanks from BOC. All of these components are being set in place and grouted on to their platforms, which marks the end of the major plant installation phase.
Operation is expected to begin by the end of 2015, and will continue for at least one year. During this time it is expected to demonstrate LAES providing a number of grid balancing services including Short Term Operating Reserve (STOR) and supporting the grid during the winter months with peak tariff management (Triad avoidance), as well as testing for frequency regulation performance against standards required by one of the large US system operators. KiWi Power was selected to arrange the commercial aspects of the plant’s interaction with the National Grid. The plant is due to be operational towards the end of 2015.
Dr Jill Cainey, Electricity Storage Network, said: “Electricity storage, like LAES, offers critical support to the GB system at a time when the penetration of variable generation and the loss of high carbon plant causes real system stress. The flexibility that electricity storage offers not only allows greater deployment of low carbon generation, but provides vital services, such as frequency response and inertia, to ensure a secure and stable electricity supply."
Yoav Zingher, chief executive at KiWi Power, said: “As one of the first LAES demonstrators in the world it provides a unique opportunity to provide grid balancing services at a time when the UK capacity reserve margin is at an all time low."
Highview and project partners, energy and waste management company, Viridor, were awarded more than £8 million funding from the Department of Energy and Climate Change (DECC), to design, build and test a pre-commercial LAES technology demonstrator alongside Viridor’s landfill gas generation plant at Pilsworth Landfill facility in Greater Manchester. In addition to providing energy storage, the LAES plant will convert low-grade waste heat, from the GE Jenbacher landfill gas engines, to power. Highview has previously operated a grid connected 350kW/2.5MWh LAES pilot plant in Slough, Greater London from 2011-2014 at SSE’s 80MW biomass plant.