Energy Storage to Support Integration of In-Stream Tidal Energy with Weak Electricity Grids

In-stream tidal energy conversion systems can reduce fossil-fuel use and greenhouse-gas emissions bygenerating renewable electricity from the tides. However, the ebb and flood of tides are naturally sinusoidal andconsequently the electricity output varies in a considerably different manner than end-use demand. Energystorage (e.g. batteries) can overcome this limitation by providing short-term temporal decoupling of thegeneration and demand systems. The objective of this research is model development and analysis ofdistributed energy storage suitable for placement at the interconnection point between the tidal generator andweak distribution electricity grids. Such interconnections will occur at seaside communities which have ampleaccess to tidal resource but which are located far from electrical substations.As interest in tidal energy has only recently renewed (c. 2006) the scientific literature lacks numerical energymodels for this resource, presenting a research and commercial opportunity. The approach used for this studyconsists of numerical modeling of energy storage systems with tidal generators and distribution electricitygrids. Efforts will be focused in three areas: i) combine recent tidal resource models with tidal generatorspecifications to model the electricity generation profile; ii) combine electricity demand information anddistribution feeder specifications to model end-use demand and electricity export capabilities; and iii) create amodel to assess power/energy characteristics required of the storage system to maximize tidal generation whileoperating within the existing electricity grid limitations.This research will support industry and government initiatives in tidal energy conversion by allowingincreased penetration rates and integration with the electricity grid. Graduate students involved in this researchwill be trained in numerical modeling techniques as they produce new knowledge. This will be disseminated tothe industry partner through a technical report and presentation. Involved students will enter both the researchworkforce and burgeoning renewable energy industry.