Commercial Solar for Warehouses 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.

If your self-consumption rate sits below about 60%, or your site has significant evening or night load, a battery shortens payback and lifts return. For most daytime-operating warehouses and factories already at 70%-plus self-consumption, batteries are optional and we sometimes advise against them to keep payback tight. We model both cases in the proposal.

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.

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.