House O’Hill

Green Cat provided all elements of consultancy and development support services for the House O’Hill co-generation project which was the first of its kind in Scotland. Green Cat developed the site from initial conception, consenting and build and continue to provide operational asset management for the site.

Three wind turbines were developed at the site and have been operational since 2010, the turbines are some of the best performing wind turbines in mainland UK with an average load factor in excess of 40%. A ground mounted solar PV array was later developed and added following a detailed study with the aim of balancing the export profile across the year utilising the existing grid connection capacity.

The construction of combined wind and solar generation at a site is advantageous to the developer providing a greater consistency of generation across the year, leveling out the natural peaks and troughs of the generation profile when these technologies are isolated. The combination of the generation profiles of wind and solar are a particularly good fit due to the generation peaks being in opposite seasons. This means that a grid connection for the full combined capacity is not necessary in most cases.

The export limit of the House O’Hill development is 2.4MW, however, the addition of solar has allowed for a total installed site capacity of 4MW. This has been calculated as the optimum scale of solar installation with the resource and curtailment analysis identifying a curtailment requirement of only 3%. Similar studies can be undertaken to match on-site demand with generation.

The co-location of wind and solar technologies has proven a success at this site, by optimising the grid connection infrastructure. It is considered that the addition of battery storage in the future would provide further optimisation and would virtually eliminate the issues around intermittency of wind and solar, ensuring the export from the overall scheme is constant, reliable and renewable.