OST Energy (OST), an independent engineering consultancy, has supported Aviva Investors in the acquisition of a 60.5-MW, four-project wind energy portfolio from developer Renewable Energy Systems (RES). OST is also providing ongoing support in the acquisition of a fifth project.


Leading technical advisor, OST Energy, has helped support and oversee Aviva’s wind portfolio acquisition of five UK wind farms from developer RES.

Prior to the acquisition, OST acted on behalf of Aviva as Technical Advisor, providing technical due diligence, yield analysis, and contractual support services to inform the purchase of the 15-MW Jacks Lane, 10-MW Woolley Hill, 18-MW Den Brook, and 17.5-MW Turncole wind farms in the UK.

The business was then engaged as Owner’s Engineer (OE) to carry out construction monitoring support at Den Brook and Turncole, focussing on the inspection and monitoring of works on site, along with health and safety and quality assurance. Den Brook achieved commercial operation in October, with Turncole scheduled to be commissioned in early 2017.

OST will subsequently deliver operational monitoring services for all four wind farms. Also, to ensure that Aviva’s newly acquired UK wind portfolio delivers long-term benefits, OST was engaged to provide an independent perspective that will help mitigate project risks for a period encompassing the acquisition, construction, and early operational phases.

“A lot of work goes in during the early project phases to ensure that generation assets are well-placed to deliver the steady long-term income stream we need to support our clients,” said Jolanta Touzard, Assistant Fund Manager – Infrastructure, Aviva Investors. “OST’s technical due diligence has helped us determine that these four initial assets are a fine addition to our existing portfolio of wind energy investments.”

In advance of the acquisition, OST provided comprehensive technical due diligence reporting, covering all critical project documentation, from permits to supply contracts and power purchase agreements, in order to minimize contractual risk. OST reviewed the existing Energy Yield Assessments (EYA) for each of the projects, in addition to the Operational Energy Yield Analysis for those currently in operation. This work allowed OST to advise on measures to mitigate performance risk and ensure that each wind farm is well placed to deliver against long-term expectations.

Following on from the OE role, OST will monitor operational risk at each of the projects by means of quarterly and annual reporting on asset management performance. RES will continue to provide asset management services to the projects, with responsibility for the day-to-day operation of the wind farms, including delivering and managing community benefit initiatives.

“UK wind energy continues to set extremely high-performance standards, and its appeal to the domestic and global investment communities is clear to see,” said Nick Fleming, Director of Wind, OST Energy. “That said, the ability of the market to retain this interest is contingent on its ongoing capacity to deliver low-risk, steady return on investment. Staying on top of project risks, from the point of acquisition, throughout the construction and operational phases, is a huge part of ensuring that a wind energy investment meets this requirement.”