Commercial Solar for Offices in South Wales

At 30p/kWh grid electricity, a 100 kWp system generating 95,000 kWh/yr with 70% self-consumption delivers around £24,000 of year-one benefit against c. £85,000 capex, a 3.5-year simple payback. Under Annual Investment Allowance first-year 100% relief, post-tax payback is closer to 2.6 years. South Wales yields 940 to 985 kWh/kWp/year depending on postcode, comfortably enough for commercial solar to be cashflow positive from month one with a PPA.

A Power Purchase Agreement is a financing arrangement where we fund and install a rooftop solar system at no upfront cost. Your business buys the electricity the system generates at a fixed, RPI-indexed rate that is lower than your grid tariff. The PPA typically runs 10 to 25 years. At the end you can extend, buy out at a pre-agreed residual value, or have the system removed. It suits businesses that want immediate savings without capital outlay and that are credit-worthy with a stable site.

Yes, depending on organisation type. Welsh SMEs and public bodies can access the Welsh Government Energy Service, Ynni Cymru Capital Grants (approximately £10 m in 2026-27, £25,000 to £1 m per project) and Development Bank of Wales Green Business Loans. Welsh public-sector bodies use Salix Wales Funding Programme rather than the English Public Sector Decarbonisation Scheme. Farms may be eligible under Farming Connect. Always check current-year terms before committing.

Most rooftop non-domestic solar is permitted development under the Welsh General Permitted Development Order amendments, subject to limits such as 20 cm protrusion on pitched roofs and 1 m on flat roofs, and with restrictions for listed buildings and conservation areas. Ground-mount beyond those PD limits needs a full planning application. Systems over 10 MW are a Development of National Significance determined by Welsh Ministers.

G99 is the Engineering Recommendation governing how generation equipment connects to the UK distribution network. For commercial solar above 16 A per phase, you need G99 approval from your District Network Operator before export. In South Wales that is National Grid Electricity Distribution (NGED, formerly Western Power Distribution). Type A connections are the standard sub-1 MW route, typically 3 to 6 months in 2026.