The VRB Energy Storage System being sold to Tapbury Management Limited for Phase II of the Sorne Hill Wind Farm in Ireland has been increased in size to a 2MW x 6hr system.

The VRB Energy Storage System (VRB-ESS) being sold to Tapbury Management Limited for Phase II of the Sorne Hill Wind Farm in


has been increased in size to a 2MW x 6hr system. The deal confirms Sorne Hill as


’s largest energy storage project.

The value of this contract to VRB Power has increased from $6.3m to approximately $9.4m.

The increase in size of the contract follows publication of an independent feasibility study on the implementation of the VRB-ESS at Sorne Hill, which was jointly commissioned by Sustainable Energy Ireland (SEI) and Tapbury Management Limited.

The study anticipates internal rates of return to purchasers of VRB Energy Storage Systems in Ireland of up to 17.5%, increasing the economic appeal of wind power in Ireland and potentially across Europe and beyond.

The study also concluded that the optimum size of the system is 2MW of power with six hours of storage and the ability to provide 3MW of pulse power for 10-minute periods every hour in order to deal with short-term volatility in wind generation.

John Ward, Director of Tapbury Management Limited, said: ‘The study provides technical and economic validation for a number of the key revenue streams that we had previously identified for the planned implementation of the VRB-ESS at Sorne Hill. The increase in the size of the system enables us to maximize these revenue streams and, when combined with additional market based payments, provides a strong economic case for this purchase. In particular, the study demonstrates the potential for purchasers of VRB Energy Storage Systems in the Irish market to achieve a very healthy IRR of 17.5% on their investment.’

He added: ‘This study now provides us with the data and validation required to finalise our off-take and other revenue agreements for Sorne Hill. This will in turn enable us to complete our project finance requirements and execute final contracts with VRB Power Systems.’

The study focused on wind generation at Sorne, and also showed the potential for storage across Ireland with respect to the planned roll out of wind power and Ireland’s Kyoto commitments.

The study highlighted the fact that the VRB-ESS will allow wind power to be dispatched in the same way as 'base load and peaking plant' generation. It will enable the integration of large amounts of wind energy without causing grid instability, thereby improving the economics of wind generation.

David Taylor, CEO of Sustainable Energy Ireland, said: ‘Wind energy is one of Ireland’s largest accessible renewable energy resources. In the recent Energy White Paper, the Irish Government set a target to deliver 33% of electricity from renewable sources by 2020, a significant proportion of which will be provided by wind. Integrating large amounts of wind power presents many challenges with regard to grid upgrade costs, power quality and of course intermittency management. Through its funding of this study, SEI is therefore pleased to be supporting activities which will enhance the understanding and market uptake of these energy storage technologies and which will help us to realise the full potential of wind energy in Ireland.’

Tim Hennessy, CEO of VRB Power Systems, said. ‘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 800MW up to and beyond the 3,000MW currently contracted or proposed, and to deal with the intermittency and constraint issues already being experienced. It is estimated that at least 700MW of storage may be required across Ireland. This sale will provide us with a ‘blue-print’ to execute on similar opportunities in Ireland and worldwide,’ concluded Hennessy.

The agreement between VRB Power and Tapbury Management Ltd remains subject to execution of final contracts.