Liverpool Wind Energy Storage Project Inc. is a holding company for an integrated wind generation and energy storage project to be located in Liverpool, Nova Scotia. The project has secured a contract with Nova Scotia Power and the NS Department of Energy for 3.6 MW of wind energy through the Community Feed-In Tariff (COMFIT). The project will consist of 4.7 MW of installed wind generation plus integrated energy storage technology. The total project cost is approximately $16 million and will be operational in early 2017.
The electricity distribution grid in Liverpool is capacity constrained, meaning that the amount of electrical power that can be fed into the grid is limited. In Liverpool, this limit is 3.6 MW, which represents the minimum load on substation's distribution feeder. This type of constraint is not unique to Liverpool, or even to Nova Scotia. Electricity systems were largely designed to be centralized energy distribution systems, with a one-way flow of electricity from large generating facilities, through transmission lines, down to distribution circuits and eventually to end users. Today's electricity grids are more complex, with distributed renewable energy generation from feeding into all levels of transmission and distribution grids. The capacity limits are in place to ensure electricity being fed into distribution grids does not back-feed onto the transmission grid.
Capacity limits represent a barrier to renewable energy development, but are a great opportunity for energy storage. At the Liverpool project, energy storage is effectively being used to extend the capacity limit. Instead of building a 3.6 MW wind farm that complies with the capacity limit, a 4.7 MW wind farm is being built along with an energy storage system. When the output from wind turbines exceeds 3.6 MW, energy is stored. When the output of the wind turbines falls below 3.6 MW, the stored energy is released. The wind and energy storage system will continue to respect the 3.6 MW limit, but the project ultimately results in more renewable energy fed into the grid, at a more consistent rate.