Commercial solar and renewable energy for south Wales businesses

Where the commercial demand sits across the four authorities

The four unitary authorities covered here sit in a ring around Cardiff and hold most of the region's industrial floorspace. Barry is the largest town in the Vale of Glamorgan and the region's working port. Torfaen contains Cwmbran, built as a new town with its industry planned in from the start, plus Pontypool and Blaenavon further up the Afon Lwyd. Rhondda Cynon Taf runs from the M4 corridor at Llantrisant and Nantgarw up into the Rhondda and Cynon valleys. Bridgend covers the coastal strip from Porthcawl through Pyle and Cornelly and inland to the Llynfi valley at Maesteg.

All four are partners in Cardiff Capital Region and members of the South East Wales Corporate Joint Committee, established by regulations in April 2021 and responsible since 30 June 2022 for preparing the Regional Strategic Development Plan and Regional Transport Plan across ten councils and around 1.5 million residents. That matters commercially, because strategic employment sites and regional energy planning are now co-ordinated above individual council level.

The energy profile is not uniform. Barry carries chemical and bulk handling loads next to a deep-water port. Treforest Industrial Estate, which Rhondda Cynon Taf describes as home to over 400 businesses employing over 4,000 staff, is a dense mix of light manufacturing, distribution and trade counters. The Cwmbran estates carry engineering and aerospace supply chain work. Bridgend is dominated by large-footprint sheds on former Royal Ordnance Factory land at Waterton. Each of those profiles points at a different first move, and Cardiff itself is covered on its own page rather than here.

Matching the technology to the estates, docks and parks here

Roof-mounted solar suits the single-storey shed better than any other building type, and this region is full of them. Bridgend Industrial Estate, made up of the adjoining Waterton, Bridgend and North Road estates, offers long unbroken roof runs on generous plots. Springvale Industrial Estate off Cwmbran Drive and Llantarnam Park to the south of Cwmbran give the same shape within a few miles of M4 junction 26. Village Farm Industrial Estate at Pyle and Atlantic Trading Estate at Barry Docks are smaller-unit estates where a landlord-led or estate-wide scheme usually works better than unit-by-unit installs. Bro Tathan Business Park at St Athan, part of the Cardiff Airport and Bro Tathan Enterprise Zone, is a large aerospace and advanced manufacturing site with substantial single-storey roof area.

Valley sites need different handling. The floors of the Rhondda, Cynon and Afon Lwyd valleys are narrow, the roofs are older and the spans shorter, and the valley sides throw genuine shade at both ends of a winter day. That does not rule solar out, but it changes the design. String layout and module-level optimisation matter more, and an array sized to base load usually beats one sized to fill the roof.

• Deep-plan warehouse or factory on weekday daytime shifts: rooftop PV first, because 55 to 85 per cent self-consumption is achievable without storage.
• Evening or weekend load, or an export-constrained connection: battery storage of 30 kWh to 1 MWh, lifting self-consumption to 80 to 95 per cent.
• Offices, leisure, care and hotel stock in Barry, Cwmbran, Pontypridd and Bridgend: heat pumps running at a COP of 3 to 4 in place of gas.
• Retail parks, logistics yards and fleet depots near M4 junctions 32 to 37 and along the A4042: EV charging from 7 kW up to 350 kW.
• Exposed upland sites above the valleys, and process sites with a constant heat demand: wind or CHP at 5 kW to 500 kW.
• Port and heavy industrial land at Barry: Associated British Ports already runs a 5 MW solar array across 37 acres at the Port of Barry, and has more than 100 acres earmarked for a clean growth hub.

Welsh climate law sets a different bar to England

Wales legislates its own climate targets. Under the Environment (Wales) Act 2016 the net zero date is 2050, with legally binding interim targets of a 63 per cent cut by 2030 and 89 per cent by 2040 against a 1990 or 1995 baseline depending on the gas, and five-year carbon budgets in between. Carbon Budget 3, covering 2026 to 2030, requires an average 58 per cent reduction and carries a zero per cent carbon credit limit, so it must be met by domestic action. Alongside that, the Welsh public sector carries an ambition to be collectively net zero by 2030, which is a decade ahead of most equivalent commitments in England.

That 2030 public sector date is why all four authorities on this page share the same target year for their own operations:

• Vale of Glamorgan Council, through Project Zero, is working to reduce council carbon emissions to net zero by 2030.
• Torfaen County Borough Council publishes its work under a Net Zero 2030 heading and reports procurement emissions down by nearly 30 per cent since 2019/20.
• Rhondda Cynon Taf's climate change strategy is titled Making Rhondda Cynon Taf Carbon Neutral by 2030 and commits the council to being carbon neutral by that date.
• Bridgend County Borough Council declared a climate emergency in June 2020 and has committed to the Net Zero 2030 target as an organisation.

Council supply chains and Wales-wide energy planning

For a private business the practical consequence of those targets is procurement. Councils, health boards, colleges and housing associations across the region increasingly ask suppliers for their own emissions position, and Torfaen has said it is working with Cardiff Council on a long-term procurement strategy intended to help suppliers cut emissions. If you tender into the Welsh public sector, your generation and metering evidence starts to sit in the bid rather than the marketing.

Wales also went further than any other UK nation on mapping the transition. It was the first nation to reach full Local Area Energy Planning coverage across all 22 of its local authorities, with the plans aggregated into a national energy data set. Torfaen's plan sets short to medium-term actions from 2024 to 2030 and sat alongside 22 grants totalling £360,000 issued in 2024 through the UK Shared Prosperity Fund for energy efficiency measures. Bridgend has run practical projects on the same basis, including its own new industrial units at Village Farm Industrial Estate, Pyle, which the council specifies with solar panels, air source heat pumps and EV charging points to cut occupier running costs.

These plans identify where heat and generation are expected to change street by street and substation by substation. That is genuinely useful intelligence when you are deciding which of several sites to invest in first.

Grid connections and what devolved planning adds

The distribution network operator for this whole area is National Grid Electricity Distribution (South Wales) plc, formerly Western Power Distribution, covering an area running from the Severn across to Pembrokeshire. Barry, Cwmbran, Pontypool, Pontypridd, Aberdare and Bridgend all connect through the same operator and the same application route.

Very small generation connects under G98 as a notification, where each device and the combined total sit within 16 A. Anything larger needs a G99 application lodged before equipment is ordered. Build the quotation period into the programme rather than discovering it after the roof survey, and ask National Grid Electricity Distribution for the prescribed period that applies to your specific application when you submit it. Where a local primary substation is already tight, the usual answers are an export limitation scheme, a battery to absorb midday generation, or an array sized to base load rather than to roof area.

Planning and building regulations are devolved in Wales, and the differences here are material:

• Roof-mounted solar on a non-domestic building is generally permitted development, subject to conditions: no more than 200 mm projection from the roof slope or wall, no more than one metre above the highest part of a flat roof, at least one metre in from the external edge of the roof, glint and glare minimised, and removal once no longer needed for generation.
• Those rights do not apply to a listed building, a building within the grounds of a listed building, or a scheduled monument.
• Stand-alone ground-mounted solar is far tighter in Wales than most people expect. Permitted development covers one installation only, up to 9 square metres, no higher than 4 metres and at least 5 metres from the boundary. Any field-scale array needs full planning permission.
• Nothing qualifies as permitted development within 3 km of an airport or aerodrome, which directly affects sites around Rhoose and St Athan.
• Non-domestic buildings in Wales work to the Welsh edition of Approved Document L Volume 2, buildings other than dwellings, rather than the English document, and a revised Welsh edition takes effect on 4 March 2027.
• Under the Infrastructure (Wales) Act 2024 a generating station other than wind, at 50 to 350 MW, is a significant infrastructure project consented by Welsh Ministers. Commercial work at 30 kW to 2 MW stays with the local planning authority. At Treforest Industrial Estate and Parc Nantgarw a local development order adopted in 2017 already removes the need for a formal planning application for certain employment development.

A modelled scenario for a Bridgend distribution unit

The following is a modelled scenario, not a real named client. It is built from the ranges used across this site so you can sanity-check any quote you receive against it.

Take a 60,000 square foot distribution unit on the Waterton side of Bridgend Industrial Estate, single shift, weekday daytime operation with chilled storage running continuously, drawing around 1,000,000 kWh a year. A 500 kWp array needs roughly 2,750 square metres of clear roof at 5 to 6 square metres per kWp, which a unit of that size can carry once rooflights, plant and access zones are excluded. At 900 to 1,000 kWh per kWp the array produces 450,000 to 500,000 kWh a year.

• Installed cost at £1,000 to £1,150 per kWp: £500,000 to £575,000.
• Self-consumption at 60 to 65 per cent: 270,000 to 309,000 kWh used on site.
• Value of that at 27 to 30p per kWh: £72,900 to £92,700 a year.
• Export of the balance at 5p per kWh under the Smart Export Guarantee: £8,300 to £9,000 a year.
• Total annual benefit £82,000 to £101,000 once export and demand-shift are added, giving a payback of roughly five to seven years, around six in the middle of the range.
• Adding a 300 kWh battery at around £165,000 lifts self-consumption towards 85 per cent. That moves about 95,000 kWh a year off a 5p export price and onto a 27 to 30p avoided import price, worth roughly £23,000 a year and paying the battery back in about seven years on its own.

What projects cost here and how firms fund them

Installed cost across the region runs £600 to £1,300 per kWp. Where a site lands in that range is driven less by the panels than by the building. Much of the industrial stock at Waterton, Treforest, Springvale and Atlantic Trading Estate dates from the 1960s to the 1980s, so roof sheet condition, purlin capacity, asbestos-cement coverings and safe access account for a large share of the price. Exposed coastal sites at Barry and Porthcawl add wind loading and fixing specification. A constrained connection adds network reinforcement cost.

The funding routes that actually apply to commercial projects here are these:

• Annual Investment Allowance. AIA gives a 100 per cent deduction against taxable profit in year one on qualifying plant and machinery, capped at £1m a year. Solar PV is special rate plant under HMRC's classification at CA22335, so AIA is the route to a full year-one deduction on a solar project. Full Expensing is a main rate allowance and does not deliver 100 per cent on solar; special rate assets attract the 50 per cent first-year allowance instead, and spend above the AIA cap goes into the special rate pool. Confirm the position with your own accountant before you commit.
• Smart Export Guarantee. Exported units earn 4 to 15p per kWh depending on supplier and tariff. Worth shopping around, because the spread is wide.
• Power purchase agreement or funder ownership. Zero capex, the funder owns the asset and you buy the output below grid price. This is the common route where the AIA is already committed elsewhere, or where the occupier does not own the roof, which is normal on multi-let estates such as Village Farm and Atlantic Trading Estate.
• EV charging grants. The Workplace Charging Scheme contributes up to £500 per socket, covering up to 75 per cent of purchase and installation cost, for up to 40 sockets across all sites, and runs until 31 March 2027.
• Industrial process funding. The Industrial Energy Transformation Fund closed to new applications and no successor fund is planned, so process-heat projects around Barry Docks now rely on capital allowances, PPA funding or Welsh Government business support rather than a dedicated industrial decarbonisation grant.
• Public sector routes. The Public Sector Decarbonisation Scheme is for public bodies only, not private firms. In Wales, councils including Torfaen have separately used Salix Finance interest-free loans to put solar onto community buildings.

A sequenced roadmap that keeps each stage smaller

Order matters more than technology choice. Working through these five stages in sequence keeps every stage smaller and cheaper than it would be if you started in the middle.

• Measure. Pull twelve months of half-hourly meter data and match it against the shift pattern. Efficiency measures typically remove 8 to 25 per cent of consumption at a 1 to 4 year payback, and every unit removed here is a unit you never have to generate, store or connect for.
• Generate. Size the array to the corrected load rather than to the roof. Solar at 30 kW to 2 MW covers almost all the commercial stock in this region, at £25,000 to £1.5m and around six years to payback.
• Store. Add 30 kWh to 1 MWh of battery once the real generation profile is known, at £20,000 to £500,000 and roughly seven years, taking self-consumption from 55 to 85 per cent up to 80 to 95 per cent.
• Electrify. Heat pumps at 30 kW to 1 MW thermal, £30,000 to £750,000, about eight years, and EV charging at 7 kW to 350 kW, £3,000 to £150,000 or more, about five years. Do the fabric and the controls first, because a heat pump on an uninsulated 1970s unit simply relocates the cost.
• Fund. Choose between capex with AIA relief and a funder-owned PPA at zero capex once the technical scope is fixed, not before.

Working with us across the region

We work across more than five technologies and operate UK-wide. We are MCS certified, NICEIC Approved, OZEV approved, a RECC member and TrustMark registered. Panels carry a 25-year performance warranty and our workmanship warranty is insurance-backed.

Send your site address, a roof plan and the last twelve months of electricity bills through the quote form and we will come back with a sized proposal, a modelled saving using the ranges on this page, and a G99 connection route for your site.