UK rural businesses are no different. With solar equipment costs at historic lows and favourable policy support for renewables, now could present a strong opportunity to invest in rooftop solar PV.

Why now?

The past few years have seen low equipment pricing for solar PV, but there are signs that prices are starting to rise, making now an opportune time to invest. One potential inflationary factor is China eliminating the VAT export rebate for PV products (cell wafers and panels), which directly reduces subsidies for solar manufacturers and increases export costs, likely to raise project capital expenditure by 5-10%. However, this is unlikely to be a decisive factor in whether a project proceeds. With farm margins already squeezed, investing in solar is not a decision to take lightly.

Where to start?

Farmers should begin by assessing whether solar aligns with their wider business goals; how much generation capacity is needed; is battery storage required to manage differences between generation and demand; and what is achievable within budget? These are long‑term investments (25-30 years), so it’s important to plan not only for current needs but also for future requirements.

Given the wide variation in farm rooftop sites, each with different characteristics, constraints, and preparatory works, it’s difficult to estimate costs and payback without full site details. Costs of £800-£1,200 per kW are often quoted and may be realistic for straightforward projects (such as installing solar on a new barn roof), but more complex schemes can differ significantly.

Payback periods can range from a few years to several decades, so a cautious approach is essential. A thorough assessment of site constraints should form a part of the feasibility study before decisions are made.

Considerations:

• Structural integrity: Is the building and roof structurally suitable for solar PV?
• Asbestos: Does the roof contain asbestos?
• Positioning: A south‑facing roof with a 30–40 degree pitch is generally optimal.
• Roof area: Generally around 4 m² of roof space is needed per 1 kWp of generation capacity, although this varies depending on panel type, size, and wattage.
• Electricity supply: For single‑phase supplies, an export limit of 3.68 kW applies.
• Grid availability: Are new connections permitted by the local Distribution Network Operator (DNO)?
• Aesthetics and planning:Rooftop solar generally falls within permitted development, but some projects may still require planning consent.

The future

Solar technology has advanced significantly, helping to drive costs down, with further improvements expected. PV manufacturers are already exploring the substitution of silver with base metals such as copper to mitigate rising precious metal costs, while panel efficiency continues to improve.

In 2020/21, the efficiency of new monocrystalline panels was around 20-21%; today, it’s approximately 25-28%, representing a substantial improvement in a short space of time. The supply chain is also becoming more “circular”, with work underway in Italy to develop panels that are up to 99% recyclable.

As solar technology continues to evolve, rooftops can present a real opportunity. However, viability ultimately depends on the fundamentals, which must be examined in detail before any commitment is made.

Further information

Contact Henry Cody or Ashley Lilley

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