An electricity storage system is to be tested at Sorne Hill wind farm in Donegal, Ireland. Tapbury Management Limited, which manages the recently commissioned 32 MW project, plans to test a Vanadium Redox Battery Energy Storage System (VRB-ESS) developed by Canadian company VRB Power Systems. The system will allow power generated off-peak to be stored and supplied to the grid at a scheduled time. A feasibility study currently underway is being 50% funded by government agency Sustainable Energy Ireland. Under the $6.3 million sale agreement, VRB will supply a 1.5 MW x eight hour system, giving 12 MWh of power, to be coupled to the second phase of the wind farm. An additional 6.9 MW of wind turbines are due to be installed in autumn 2007. Subject to the performance of the system, Tapbury has an option to expand the storage to cover the existing 32 MW of the wind farm. With some 3000 MW of wind energy in the application process in Ireland there could be a need for over 700 MW of storage, says Tapbury's John Ward. "This is the culmination of around two years' work and we see it as only the beginning of an expansion in the size and number of wind generation installations in Ireland." Ireland has one of the best wind resources in the world, he says, but because the wind does not blow all the time it could not be fully exploited without storage, he claims.