Grazeley solar farm costs spiral – but new plan sees AWE Burghfield as biggest customer

The cost of West Berkshire Council's planned solar farm at Grazeley has gone up from £10m to £16.3m.

The original business plan for the 75-acre site has also been changed, meaning the council wants to put in a bigger connection, and make more money.

Despite the impact of interest rates and rising material costs, the council says the latest business case update demonstrates that the provision of a solar farm at Grazeley is still a financially and environmentally viable proposition.

Officers will be asked to construct a deal, potentially with AWE, at Burghfield which it is claimed could create around £3m in income, and allow West Berkshire to claim a 37 per cent reduction in its carbon footprint.

A report to this week's executive committee, which meets on Thursday night, says the rise in energy prices has meant that the rate of return for the project has risen from the 2020 figure of four per cent to between 5.62 per cent and 7.60 per cent.

Two potential grid connection options are available to the council, the choice of which could have an impact on the scheme economics.

The cheaper option – costing £14.98m – would involve laying a cable beneath the highway between the site and a point designated by SSE; a distance of approximately 3.4km.

Negotiations are under way with landowners to agree to shorten the route and reduce the amount of hard dig, however the worst case scenario along the road has been assumed for this business case.

The second, more expensive option, at £16.3m is connecting into the grid via AWE’s Burghfield substation.

The council says informal discussions have taken place with both AWE and SSE which have indicated this may be feasible. It says AWE has also expressed an interest in purchasing green energy locally.

The difference in cost from the grid option is due to a slightly shorter cabling distance to the AWE site, but there is a £1.5m addition due to potential work required to connect to the grid through AWE.

Early informal discussions indicate that AWE’s power requirements are such that it could potentially take approximately 73 per cent of the generated energy from the Grazeley site, with the remainder being exported to the grid.

Power supply agreements are over 30 years and involve the purchase of power for a fixed price.

This gives the council security of income for the 30-year life of the solar farm and generates savings for AWE in that it will receive relatively cheap green energy for that time.

Consideration is being given to using the solar farm for sheep farming during its life.

The proposed scheme design also includes additional tree and hedge planting, the creation of ponds and seeding with wildflower seed-mix, and seeding for winter birds.

The scheme will also include the installation of bird and bat boxes across the site.