Commercial solar surveys in Cardiff

Key facts

Grid connection with National Grid Electricity Distribution

Cardiff is in the South Wales licence area of National Grid Electricity Distribution (NGED). North Wales is served by a different operator, so a business with sites across Wales may deal with two. Commercial systems above the G98 limits need G99 approval before connecting. Boundaries can vary at the edges of licence areas, so confirm your operator with the Energy Networks Association postcode tool.

South Wales has seen strong growth in solar and other generation, and export capacity varies by location. Sizing the array to daytime demand, adding a battery or using a G100 export limitation scheme can keep the connection simpler. Our page on G99 and DNO applications explains the process.

Planning in Cardiff and Wales

Cardiff Council decides applications in the city, including the Wentloog industrial area off Lamby Way, the Port of Cardiff in Cardiff Bay, operated by Associated British Ports, and Cardiff Gate Business Park. Cardiff Airport and the St Athan aerospace site are in the Vale of Glamorgan, and sites to the east and north fall to Newport, Caerphilly or Rhondda Cynon Taf.

Wales has its own planning rules. Permitted development for solar on non-domestic buildings sits in Part 43 of the Welsh General Permitted Development Order, and the Welsh Government has confirmed there is no limit on the number of panels on a non-domestic roof, provided the conditions in that Part are met. Those conditions cover matters such as how far panels project and protected sites. Listed buildings and conservation areas need more care: Cardiff Bay's historic core around Mount Stuart Square and the former Coal Exchange is one example. Our planning permission guide explains how applications work, and the Welsh Government's guidance on non-domestic solar sets out the current Welsh conditions.

The local economy and solar

Cardiff is the seat of the Welsh Government and the Senedd, with a large public sector, financial and professional services, creative and media industries, universities and a major hospital estate. Around the city are port activity, logistics and manufacturing, and the wider region includes a compound semiconductor cluster. Public buildings, hospitals and campuses, distribution sites at Wentloog and manufacturers with daytime shifts are the usual strong candidates. See our healthcare page for how hospital and clinic estates approach solar.

Clean air, transport plans and charging

Cardiff does not have a charging clean air zone; the council's business case favoured non-charging measures. The city has, however, been looking at a road user payment scheme to fund public transport. In July 2026 the council's cabinet backed a workplace parking levy as its preferred option to develop further, with a congestion charge and a do-nothing option also included in public consultation. Any such scheme would need new legislation from the Welsh Government and would take several years to introduce.

Employers with large car parks may want to keep an eye on this when planning staff and fleet charging. A carport or rooftop array can supply part of the daytime charging demand; see EV charging for business.

Roofs and buildings in Cardiff

• Victorian and Edwardian commercial buildings in Cardiff Bay and the city centre, many listed, with slate roofs and heritage constraints.
• 1960s to 1980s industrial units across the city's older estates, where asbestos cement roofs are common and must be surveyed first; see asbestos roofs.
• Modern distribution sheds and business park offices at Wentloog and Cardiff Gate, with profiled metal or flat roofs that suit larger arrays.

Expected generation

Cardiff's position on the south Wales coast gives good yields by UK standards. A well-oriented array typically produces about 900 to 1,000 kWh per kWp a year (indicative). The European Commission's PVGIS model gives close to 1,030 kWh per kWp for an ideally angled south-facing array with standard losses, and nearer 830 for a low-pitch east-west flat roof layout.

How the free survey works

Fill in the short form with your site details. We review your enquiry and call you to understand the building and your energy use. If it looks suitable we arrange a free survey with one MCS certified installer matched to the site, in person or virtual, and your details go to that installer only. There is no obligation. See our Wales page for the wider picture.