Commercial solar surveys in the South East

Key facts for commercial solar in the South East

Two network operators, one region

The South East is split between two distribution network operators. UK Power Networks covers the eastern half through its South Eastern licence area: Kent, East and West Sussex and much of Surrey. Scottish and Southern Electricity Networks (SSEN) covers central southern England through its Southern Electric licence: Hampshire, the Isle of Wight, Berkshire and much of Oxfordshire. Buckinghamshire and the edges of Surrey and Oxfordshire are split, and the boundaries do not follow county lines, so check your postcode with the Energy Networks Association tool.

The process is the same in principle with either operator: anything above G98 limits needs G99 approval before connection, and an export limitation scheme under G100 is an option where capacity is tight. The two operators publish different network capacity information and run separate application portals, so the installer needs to know which applies before preparing your application. Our G99 and DNO applications guide explains what is involved.

Yield: some of the strongest in the UK

The south coast is among the sunniest parts of the country. In our PVGIS model (version 5.2, SARAH2 data, 14% system losses), a south-facing 1 kWp array at the optimum tilt near Southampton gives about 1,080 kWh a year, and an east-west flat roof layout at 10 degrees about 890 kWh. Near Maidstone in Kent the south-facing figure is about 1,060 kWh. Further north, around Oxford and Reading, expect a little less. Real rooftops usually come in below the optimum because of orientation and shading, hence the indicative range in the table.

Planning and clean air zones

Planning follows the national rules for England. Permitted development for non-domestic rooftop solar was widened in December 2023, but conditions apply, and the South East has large protected landscapes, including the South Downs National Park, the New Forest National Park and several National Landscapes such as the Kent Downs and the Chilterns. Ground-mounted arrays and carports in or near these areas need more care. See our planning permission guide.

Two local schemes matter for fleets:

• Portsmouth Clean Air Zone is a Class B zone. It charges non-compliant buses, coaches, taxis, private hire vehicles and heavy goods vehicles, but not vans or private cars.
• Oxford Zero Emission Zone is a pilot in the city centre where zero emission vehicles travel without a charge and other vehicles may be charged. Oxfordshire County Council has proposed a wider zone; check its current status before planning around it.

If you are electrifying vehicles that run into either city, combining depot charging with rooftop generation is worth modelling. See EV charging for business.

Buildings and economy that suit solar here

The South East's commercial estate is varied:

• Kent and Sussex horticulture. Kent's orchards, soft fruit and glasshouses support packhouses and cold stores with high daytime and summer cooling demand, a strong match for solar. See our farms page.
• Ports and logistics. The Port of Dover and the Channel Tunnel at Folkestone drive distribution and freight sites across Kent, while the Solent ports at Southampton and Portsmouth support large warehousing around the M27.
• Thames Valley offices and technology. Reading, Slough and Bracknell host offices, business parks and data-heavy operations where daytime demand is steady.
• Airports. Gatwick sits in West Sussex, with associated logistics and services nearby.

Distribution warehouses with large, low-pitch roofs offer the most space, often on profiled metal sheeting. Older farm and industrial buildings may have asbestos cement roofs, which need an asbestos survey before work starts.

Support and finance

South East businesses use the national schemes for England: capital allowances, the business rates exemption for eligible onsite generation and storage plant to 31 March 2035, and the Smart Export Guarantee. See grants and support in England and confirm tax treatment with your accountant.

Cities with their own page

• Southampton: Solent port, logistics and the local network context.

How the free survey works in the South East

After you send the short form, we call to understand your site, your electricity use and which operator serves you. If the site looks suitable, we arrange a free survey, in person or virtual, with one MCS certified installer matched to the site, ideally one familiar with the relevant operator's G99 process. Your details go to that installer only, and you are under no obligation to proceed.