Sustainable Energy Ireland (SEI) has published the results of a feasibility study for the implementation of a wind energy storage facility at Sorne Hill Wind Farm, Buncrana, Co. Donegal. The analysis into the feasibility of using an innovative energy storage system showed how such a system could support an uninterrupted supply of wind-generated electricity to the national grid and significantly improve the efficiency of the energy produced.

The study, which was jointly funded by SEI and Tapbury Management Limited, which oversees the management of Sorne Hill Windfarm, examined the costs and benefits of integrating a battery-based power storage system with a 6 MW windfarm. The purpose of the report was to determine the optimum size for such a system to deliver an optimum return on investment, and to review the main benefits that this system would offer. The report concluded that the optimum battery is a 2 MW capacity battery delivering six hours of electricity storage.

Commenting on the feasibility study, David Taylor, chief executive, SEI, said “Ireland possesses a wind resource that is one of the best in Western Europe. In order to exploit this, SEI is supporting the development of strategically important technologies which will enable Ireland to use large amounts of wind power reliably. This will help Ireland reach the Government’s target to have one-third of Ireland's electricity supply coming from renewable sources by 2020.”

The storage technology, a Vanadium Redox Battery Energy Storage System  from Canadian company VRB Power Systems Inc., is designed to allow wind energy generated at off-peak times to be stored and supplied to the grid at a scheduled time. The energy storage system has the potential to increase the reliability of wind energy supply and thereby reduce the cost of providing the power reserve requirements from electricity generation plants as more windpower connects to the system. Batteries such as these can also be used to maximise the wind intensity in rural regions by providing high quality power output and storing and temporary excess wind power for later release. In this way increased wind penetration can be achieved more rapidly as the cost and effort of grid upgrades are deferred. The battery may therefore generate additional income for the wind farm by correcting power imbalances, providing premium power quality, delivering an energy trading service and providing grid ancillary services in the Single Electricity Market.

John Ward, director of Tapbury Management, said “The feasibility report provides for the first time an initial technical and economic validation for a number of the key revenue streams that we had previously identified in relation to the integration of windpower and storage. We will now build on these assumptions to finalize the project design and implementation of the pilot scheme at Sorne Hill II, which we hope to have operational by mid 2008.”

“This study demonstrates the economic viability of our systems for wind farms such as Sorne Hill," stated Tim Hennessy, CEO of VRB Power Systems. “The report also highlights the need for storage in Ireland to enable the successful roll-out of wind generation from the current installed base of approximately 800 MW up to and beyond the 3000 MW currently contracted or proposed, and to deal with the intermittency and constraint issues already being experienced. It is estimated that at least 700 MW of storage may be required across Ireland. This sale will provide us with a blueprint to execute on similar opportunities in Ireland and worldwide,” concluded Hennessy.