Agricultural solar for Cornwall farms and barns

Why agricultural solar is the fastest-paying PV in Cornwall

Cornwall farms have three structural advantages almost no other site benefits from at once: very large contiguous roof areas, high daytime electricity loads from pumps, milking parlours, refrigeration, grain drying and ventilation, and full Annual Investment Allowance eligibility that lets sole traders, partnerships and limited companies deduct 100% of the install cost against taxable profits in year one.

The result is that the typical Cornwall barn-mount system — 50kWp to 150kWp — pays back in 4 to 6 years post-tax, with 20+ years of near-free electricity afterwards. For dairy, cold store, pack and grain operations the payback is often under 5 years.

What we install for Cornwall farms

• Roof-mounted arrays on barns — steel-frame with fibre cement or metal sheet roofing. We check purlin spacing, roof condition and age before quoting. Systems usually 50kWp to 150kWp.
• Ground-mount PV — for unproductive corners or field edges. 50kWp or below sits within permitted development in most areas.
• Parlour and dairy pairings — solar sized to match milking and bulk-tank compressor load, delivering very high self-consumption.
• Battery storage — commercial-scale batteries to smooth out generation, shift peak-rate imports and support dynamic tariffs.
• EV charging for farm vehicles — 7kW to 22kW commercial chargers sited at the farm office or yard.
• Heat pumps for the farmhouse — Cornwall farmhouses are overwhelmingly off-gas. ASHPs with the £7,500 BUS grant make sense on most stone and cob properties.

Structural surveys are non-negotiable

We never quote an agricultural solar install without surveying the roof first. Older fibre cement roofs, unknown purlin spacing, rusted steel trusses and previous roof repairs all change what is possible. If the roof needs strengthening, we will say so — and sometimes the correct answer is to re-roof at the same time as installing, using the panel mounting system to share cost.

The G99 timeline for farms

Every commercial-scale farm install needs DNO approval via a G99 application. Cornwall sits in National Grid ED's South West region. Typical timelines for rural sites:

• Up to 50kW — 6 to 10 weeks, often straightforward.
• 50kW to 150kW — 10 to 20 weeks; rural overhead networks sometimes need local studies.
• Above 150kW — 20+ weeks; may need transformer or line reinforcement.

We submit the G99 application on your behalf and handle all correspondence. For sites where export capacity is constrained, we often recommend an export-limited inverter strategy plus battery storage so generation is captured, not curtailed.

Capital allowances — worked example

A 100kWp barn install at £75,000 ex-VAT against a farm's taxable profits of £90,000 in year one. The Annual Investment Allowance deducts the full £75,000, reducing taxable profit to £15,000. At 25% corporation tax that is a cash tax saving of roughly £18,750. Net cost post-tax: £56,250. Expected annual generation 95,000 kWh, self-consumption 70% at 28p/kWh, export 30% at 12p SEG — first-year saving around £22,000. Payback: just over 2.5 years post-tax.

Actual figures depend on your tax position, consumption profile and electricity tariff. We model this specifically for your farm before quoting.

Next steps

We run a free farm feasibility study that includes drone roof inspection (where accessible), structural assessment, DNO pre-application enquiry, and a full tax-modelled return on investment. Contact us or call 01209 596 002 to start the process.