Commercial solar in Test Valley

Solar in Test Valley in figures

What the figures show

Capacity in Test Valley has grown by 38% since the end of 2020, slower than the UK as a whole (69%). Most of that came in 2025 alone, when capacity went from 198.9 MW to 252.7 MW: a jump of that size usually means a large ground-mounted scheme connected.

There are 84.4 installations for every 1,000 households, above the South East median of 74.2 and above the UK median of 67.0. That is 107th of 361 council areas, and 18th of 64 in South East.

The average installation is 54.8 kW, several times a typical home system of about 4 kW, so solar farms and large commercial or farm roofs make up much of the capacity here.

What a business roof in Test Valley could generate

Modelled with PVGIS for the centre of Test Valley, a south-facing roof at 30 degrees produces about 1,044 kWh per kWp a year. That is 59th of 361 council areas; the UK median is 998 kWh.

Same sums as our commercial solar calculator: illustrative, not a quote. East- or west-facing roofs, shading and how much power you use in daylight all move these figures, and a company paying corporation tax can usually shorten the payback with capital allowances. See the cost guide for price ranges by system size.

Planning and grid connection

Test Valley follows the national planning rules for England. Permitted development rights for non-domestic rooftop solar were widened in December 2023, including removal of the old 1 MW limit, but conditions still apply, especially for listed buildings and conservation areas. Ground-mounted arrays and carports usually need an application to the council, or to a national park authority inside a national park. Our planning permission guide sets out the conditions.

Most commercial systems need G99 approval from the local network operator before they are switched on. The operator follows the postcode rather than the council boundary: our South East page covers the operators in the region, and the Energy Networks Association postcode tool confirms yours. See G99 and DNO applications.

For funding, see grants and reliefs in England.

Nearby council areas

• Winchester, about 13 miles away
• Eastleigh, about 15 miles away
• Basingstoke and Deane, about 15 miles away
• Southampton, about 16 miles away
• New Forest, about 19 miles away
• Fareham, about 22 miles away

Or see every council area and the South East page.

Where these figures come from

Installations, capacity, generation and households: Department for Energy Security and Net Zero, Regional Renewable Statistics, renewable electricity by local authority 2014 to 2025 (workbook). They cover all solar PV, homes and businesses, including ground-mounted schemes. Yield: PVGIS 5.3 (European Commission Joint Research Centre), SARAH3 data and 14% system losses, for the council area's centre point (ONS boundaries, December 2024), modelled 4 November 2026. Distances are between centre points.