Key facts
| Council area | Cornwall |
| Population | 24,360 (St Austell built-up area, usual residents, Census 2021 (ONS)) |
| Network operator | National Grid Electricity Distribution (South West licence area) |
| Main employment areas | Holmbush Industrial Estate; Carluddon Technology Park (ESAM) |
| Indicative yield | About 1,054 kWh per kWp a year (south facing, 30 degrees) |
| Nation support page | Grants and reliefs in England |
Where businesses are in St Austell
- Holmbush Industrial Estate: St Austell's largest employment site, on the A391. Cornwall Council's Site Allocations plan protects it (STA-E1) as a strategically important employment site.
- Carluddon Technology Park (ESAM): A council owned site at the heart of the West Carclaze Garden Village near St Austell, managed by Cornwall Development Company. Its Enterprise Space for Advanced Manufacturing has 32 flexible units (offices, workshops and industrial units) for advanced manufacturing, engineering and low carbon firms; the first phase was completed in 2018.
Large employers and sectors with sites here include:
- China clay (Imerys): In May 2025 Imerys announced nearly £18 million for a new dry mining plant at its Littlejohns works near Roche in the Clay Country, due by the end of 2026, which it says will cut its electricity use in Cornwall by 10%. Imerys says it supports around 3,500 jobs directly and indirectly.
- Brewing and pubs (St Austell Brewery): St Austell Brewery, founded in 1851, has its registered office on Trevarthian Road in St Austell. It describes itself as the South West's leading brewing, hospitality and drinks wholesale business, with more than 2,000 employees and 45 managed pubs.
Large, simple roofs on distribution sheds and modern industrial units are usually the quickest and cheapest to fit. Older mill, factory and workshop buildings can work well too, but often need a structural survey first, and roofs from before 2000 may contain asbestos cement: see asbestos roofs.
Grid connection
St Austell is served by National Grid Electricity Distribution (South West licence area). Almost every commercial system needs G99 approval from the network operator before it is switched on, and the question is usually how much the local network can take back. Where export is limited, a G100 export limitation scheme can let a larger array connect. See G99 and DNO applications.
Planning in St Austell
St Austell follows the national planning rules for England, decided by Cornwall council. Rooftop solar on most non-domestic buildings is permitted development, within height and edge limits, and systems above 50 kW need a prior approval application covering design and glare.
Points that come up locally:
- St Austell Conservation Area covers about 44.4 hectares of the town centre and holds 42 listed buildings, including the Grade I Holy Trinity Church and the Grade II* Market House, so roofs in the centre need more care.
Our guides on listed buildings and conservation areas explain what these mean for a solar project.
What a business roof in St Austell could generate
Modelled with PVGIS for the town centre, a south-facing roof at 30 degrees produces about 1,054 kWh per kWp a year.
| Item | Illustrative figure |
|---|---|
| System | 100 kWp, south facing at 30 degrees |
| Installed cost | £900 per kWp, so £90,000 excluding VAT |
| Generation | About 105,400 kWh a year |
| Used on site | 70% at 24p = £17,707 saved |
| Exported | 30% at 5p = £1,581 earned |
| Total a year | About £19,288 |
| Simple payback | About 4.7 years before tax relief |
Illustrative, not a quote: the same sums as our commercial solar calculator. A company paying corporation tax can usually shorten the payback with capital allowances.
Funding and support
We found no council or regional grant for business solar open in St Austell at the time of writing (November 2026). National reliefs still apply, such as capital allowances and, in England, the business rates exemption for onsite renewables: see grants and reliefs in England.
Solar across Cornwall
At the end of 2025, Cornwall had 34,740 solar PV installations with 683.0 MW of capacity, up 14% since 2020, according to government figures. The Cornwall page has the full local figures and how they compare.
Nearby towns
- Bodmin, about 10 miles away
- Newquay, about 14 miles away
- Falmouth, about 18 miles away
- Redruth, about 20 miles away
Sources
- ons.gov.uk: census2021
- ons.gov.uk: datadownload.xlsx
- cornwall.gov.uk: cornwall site allocations development plan document
- cornwall.gov.uk: carluddon technology park and employment space for advanced
- cornish-times.co.uk: huge investment announced at massive china clay pit
- staustellbrewery.co.uk: careers
- staustellbrewery.co.uk: about us
- find-and-update.company-information.service.gov.uk
- gov.uk: enterprise zones
- wired-gov.net: Twelve+new+Enterprise+Zones+go+live+05042017091559
- gov.uk: investment zones in england
- ukfreeports.campaign.gov.uk
- heritagecheck.co.uk: st austell
- Yield: PVGIS 5.3 (European Commission Joint Research Centre), SARAH3 data, 14% system losses, for the town centre, modelled 4 November 2026.
- Council area figures: DESNZ, renewable electricity by local authority 2014 to 2025.
Frequently asked questions
Who is the electricity network operator in St Austell?
National Grid Electricity Distribution (South West licence area). Most commercial solar systems need its G99 approval before they are switched on. The operator follows the postcode, so confirm yours with the Energy Networks Association postcode tool.
How much would a 100 kWp solar system generate in St Austell?
About 105,400 kWh a year for a south-facing roof at 30 degrees, modelled with PVGIS for the town centre. At 70% used on site at 24p and the rest exported at 5p, that is worth about £19,288 a year. Your own roof, orientation and use will change this.
Can a business in St Austell get a free solar survey?
Yes. Answer six short questions and we match the site with one MCS certified installer, who surveys it on site or by video call. It is free, with no obligation. Get a free survey.
Related pages
- Cornwall34,740 installations, 683.0 MW of solar and about 1,020 kWh per kWp a year for a south-facing roof.
- South WestThe strongest yields in mainland Britain, a network with limited export capacity in places, Bristol and Bath clean air zones, dairy farming and Severnside logistics.
- Commercial solar calculatorEstimate commercial solar savings and payback, with the generation, price and cost assumptions shown and sourced, and the limits of a simple estimate explained.
- EnglandCurrent solar support in England for businesses, schools, public bodies, community groups and farms, plus rates, planning and who to contact.
- Planning permissionPermitted development for commercial rooftop solar and car park canopies in England, prior approval, heritage limits, ground-mounted schemes and the other UK nations.