Region guide

Commercial solar finance in Wales: routes, loans and the sourced numbers

Reviewed by the Commercial Solar Finance editorial team — independent advisers (we take no installer or lender commissions). Last reviewed: 26 September 2026.

Commercial solar finance in Wales runs on the same six routes as England with two Welsh layers on top: Salix loan funding for public bodies through the Wales Funding Programme, and the Development Bank of Wales Green Business Loan Scheme for private firms. Yields are among the best in the UK outside the south coast — PVGIS models 1,042 kWh per kWp in Cardiff. This guide gives the sourced numbers and compares the routes.

Yield

PVGIS 5.3 models Cardiff 1,042, Swansea 1,014 and Wrexham 967 kWh per kWp a year for a south-facing 35° roof.

Welsh layers

Wales Funding Programme (Salix loans, open) and Digarbon (£20m, tertiary education) for public bodies; Development Bank of Wales Green Business Loan Scheme for businesses.

Commercial solar finance in Wales: the sourced numbers

South Wales roofs out-yield most of England outside the south coast, and Wales has kept a public-sector loan route that England lost. The figures below are public data, checked on 26 September 2026.

Data pointWales valueSource
Annual yield, south-facing 35° roof, unshadedCardiff 1,042 · Swansea 1,014 · Wrexham 967 kWh per kWpPVGIS 5.3, SARAH3 2005–2023, 14% system losses
Solar PV sites and capacity, 2024Cardiff 5,911 sites / 35.1 MW · Swansea 5,329 / 67.6 MW · Newport 3,538 / 107.7 MW · Wrexham 5,954 / 47.2 MW · Pembrokeshire 8,007 / 239.4 MW · Carmarthenshire 8,864 / 163.9 MWDESNZ, Renewable electricity by local authority 2014–2024 (30 Sep 2025)
Distribution network operatorsNational Grid Electricity Distribution, South Wales (grid supply group K) for Cardiff, Swansea and Newport; SP Energy Networks (SP Manweb, group D) for Wrexham and north WalesOctopus Energy grid-supply-point lookup, CF10 / SA1 / LL13
Public-sector loansWales Funding Programme: loan funding for energy efficiency and decarbonisation, open; Digarbon: £20m loan scheme for tertiary education, delivering; Wales Recycling Fund: closedSalix Finance, Wales page (10 Sept 2026)
SME loanDevelopment Bank of Wales Green Business Loan Scheme: an incentivised package with the loan term linked to project payback; eligibility, including project carbon-cost tests, in its key informationDevelopment Bank of Wales (26 Sept 2026)
Business rates on the arrayWales sets its own non-domestic rating rules; the England exclusion in SI 2022/405 amends the England regulations only — confirm the Welsh treatment with the Valuation Office Agency before relying on itSI 2022/405 regulation 1 (extent) — hedge, not a claim
Capital allowances (UK-wide)Solar is special-rate plant: AIA on the first £1m, 50% first-year allowance above it, 6% writing-down thereafterHMRC CA22335
VAT (UK-wide)20% on a business installation, recoverable if VAT-registered; 0% for homes and charitable buildings to 31 March 2027VAT Notice 708/6

Which finance route fits a Welsh business

RouteWho owns the arrayCapital allowancesWelsh angle
Capital purchaseYouYouStrongest lifetime return; south-Wales yields shorten payback by roughly a year against the Midlands
Green loanYouYouPriced off Bank Rate (3.75%); the Development Bank of Wales scheme is the Welsh-specific option to compare
Hire purchase / asset financeYou at the endYouCommon for 50–250kWp on owner-occupied units
Operating leaseLessorLessor; you deduct rentalsTenants and loss-makers; public bodies weigh it against the Wales Funding Programme
Power purchase agreementDeveloperDeveloperNo capital; strong yields make developer pricing competitive in Cardiff and Swansea
Wales Funding Programme (Salix)The public bodyn/aPublic bodies registered in Wales; Digarbon for colleges and universities

For a private business in Wales the sequence is the same as anywhere else: tax position first, then sizing to demand, then the route. Two Welsh specifics change the numbers — the yield, and a development-bank loan whose term follows the project's payback rather than a fixed schedule.

Worked example: 150kWp on a Cardiff distribution unit (modelled, not a client engagement)

150kWp at 1,042 kWh per kWp generates about 156,300 kWh a year. At 75% self-consumption and a 25p/kWh import rate the avoided purchase is worth about £29,300; the 25% surplus at Octopus's 12p/kWh Outgoing rate adds about £4,700. On an installed cost of £127,500 the simple payback is roughly 3.75 years before tax, with the whole cost relieved in year one by the Annual Investment Allowance for a tax-paying company. Replace the assumptions in the payback calculator and compare routes in a written finance comparison.

City guides

Town-level guides for Cardiff, Swansea, Newport and Wrexham sit under this page; the grants picture is on solar panel grants Wales, and public bodies should read public sector solar funding for the Salix split by nation.

Claims table: every figure on this page and its source

Every number and proper noun above is listed here with where it comes from and the date it was checked. If a row is not here, the figure should not be on the page.

ClaimSourceChecked
PVGIS yields: Cardiff 1,042, Swansea 1,014, Wrexham 967 kWh/kWpPVGIS 5.3 (EU JRC), SARAH3, 35° south, 14% losses26 September 2026
DESNZ 2024 sites and capacity by local authorityDESNZ Regional Renewable Statistics26 September 2026
DNO groups K (NGED South Wales) and D (SP Manweb)Octopus Energy grid-supply-point API26 September 2026
Wales Funding Programme open; Digarbon £20m; Wales Recycling Fund closedSalix Finance, Wales10 September 2026
Development Bank of Wales Green Business Loan SchemeDevelopment Bank of Wales26 September 2026
SI 2022/405 extends to England and Wales but amends the England regulationsSI 2022/405, regulation 116 September 2026
Bank Rate 3.75%Bank of England26 September 2026
Octopus Outgoing 12p/kWhOctopus Energy16 September 2026

Frequently asked questions

How much does a commercial solar array generate in Wales?
PVGIS 5.3 models 1,042 kWh per kWp a year for an unshaded south-facing 35° roof in Cardiff, 1,014 in Swansea and 967 in Wrexham (SARAH3 data, 14% system losses). Low-pitch commercial roofs yield roughly a tenth less.
Is there a Welsh loan for commercial solar panels?
Two routes: public bodies registered in Wales can use Salix's Wales Funding Programme (loan funding for decarbonisation, open) and colleges and universities the £20m Digarbon scheme; private businesses can apply to the Development Bank of Wales Green Business Loan Scheme, whose loan term is linked to project payback.
Do solar panels affect business rates in Wales?
Wales runs its own non-domestic rating rules. The England exclusion for renewables plant (SI 2022/405) amends the England regulations only, so confirm the Welsh treatment with the Valuation Office Agency before building it into a model.
Which network operator handles a G99 application in Wales?
National Grid Electricity Distribution's South Wales network (grid supply group K) for Cardiff, Swansea and Newport, and SP Energy Networks' Manweb network (group D) for Wrexham and north Wales.
Are capital allowances different in Wales?
No. Capital allowances are a UK tax: solar is special-rate plant everywhere, relieved through the Annual Investment Allowance on the first £1m, the 50% first-year allowance above it and the 6% writing-down allowance thereafter.

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