Devon is one of the sunniest counties in England. It has more solar installations per household than almost anywhere else in the country. And yet the question we hear most often from homeowners who have been thinking about it for a while is still the same one: is it actually worth it?

The honest answer is that for most Devon properties with a reasonable south, south-east, or south-west facing roof, it is. But the numbers vary enough between individual properties that a general answer only gets you so far. This post sets out what the evidence looks like, what affects the outcome, and where the caveats sit.

Why Devon is a genuinely good place for solar

Solar panels generate electricity from daylight. The more irradiance a location receives, the more a given system produces, and the faster it pays back.

Devon receives around 1,237 kWh of solar irradiance per square metre per year in Exeter, which is approximately 13% above the UK national average. The county sees around 1,552 hours of sunshine annually. That advantage is not marginal. A 4kWp system in Devon generates meaningfully more electricity each year than the same system installed in the Midlands or the North.

That irradiance advantage is already reflected in Devon’s adoption figures. Around 48,255 households in the county have had solar panels installed with an MCS certificate, representing roughly 10% of Devon homes. That is more than double the UK average of 4.6%. Devon homeowners have been voting with their wallets on this question for over a decade.

Where the savings come from

Solar savings come from two sources: electricity you generate and use yourself, which reduces what you buy from the grid, and electricity you export, which earns income through the Smart Export Guarantee.

Self-consumption is the more valuable of the two. Every unit you consume directly from your own panels saves you the full unit rate you would otherwise pay your energy supplier. Every unit you export earns the SEG rate, which is lower. This is why anything that increases self-consumption, whether that is a battery, an EV charger drawing on solar generation, or simply shifting appliance use to the middle of the day, improves the financial return significantly.

For a typical Devon household with a well-designed south-facing 4kWp system, annual generation sits somewhere between 3,200 and 3,800 kWh depending on orientation, shading, and the specific location within Devon. Without a battery, most households self-consume around 30 to 40% of what their panels produce. With a well-sized battery, that typically rises to 70 to 80%.

SEG income depends on which tariff you choose and how much you export. Rates vary between energy suppliers and change regularly, so comparing at the time of installation is worthwhile rather than relying on figures from a quote given months earlier. Your installer registers the system for SEG on your behalf as part of the handover process.

Payback period

The payback period for a domestic solar installation in Devon currently sits in the region of seven to ten years for most households, depending on system size, usage pattern, energy tariff, and whether battery storage is included.

That range sounds wide because it is. A household with high daytime electricity use, an EV on a smart charger drawing from solar generation, and a battery capturing evening demand will see a shorter payback than a household where most consumption happens at night and the system exports a large proportion of what it generates.

The point worth emphasising is what comes after payback. Solar panels carry a 25-year performance warranty, and in practice continue generating well beyond that. The years after payback represent electricity that costs nothing to generate. Over a 20 to 25 year system lifespan, the total financial return for most Devon installations is substantially positive.

The 0% VAT position

All domestic solar panel and battery storage installations currently attract 0% VAT rather than the standard 20% rate. This relief is confirmed until at least March 2027. It is not a grant and does not require an application, but it does meaningfully reduce the cost of a self-funded installation compared with what the same work would cost if taxed at the standard rate.

Honest caveats

Solar is not equally worthwhile for every property, and it is better to be clear about this than to paper over the cases where the answer is more complicated.

Roof orientation. North-facing roofs generate too little to justify the investment in most cases. East and west-facing roofs work well but produce less than south-facing equivalents. A split east-west array on a ridged roof can actually improve self-consumption for households with morning and evening demand peaks, but the total annual output will be lower than a south-facing system of the same size.

Shading. A chimney, dormer, tree, or neighbouring building that shades part of the roof for a meaningful portion of the day reduces output disproportionately. Shading is assessed at survey stage and should always be checked before the system is designed, not assumed away.

Planning to move within five years. Solar is a long-term investment. The payback period for most Devon installations sits in the seven to ten year range, so the financial case weakens if you are unlikely to stay long enough to benefit from the post-payback years. That said, solar panels generally improve a property’s EPC rating and are associated with higher sale prices, so some of the value may be realised on sale rather than through energy savings.

Roof condition. Installing solar on a roof that needs re-covering in the next few years is poor sequencing. Removing and reinstalling a solar system to carry out roof repairs later adds cost that could have been avoided. If your roof is approaching end of life, replacing it first is almost always the better order of operations.

Asbestos cement roofs. Commercial and agricultural buildings with asbestos cement roofing require specific regulatory compliance before any solar installation work can begin. This is not a barrier to going solar, but it does change the route and the cost. See our guide to solar panels on different roof types for more detail.

Does it work in winter?

Yes. Solar panels generate from daylight, not from heat or direct sunshine. Output is lower in December and January than in July and August, but generation continues throughout the year. Exeter averages around 1.8 hours of bright sunshine per day in December compared with 6.6 hours in May, but even on overcast winter days panels produce useful amounts of electricity from diffuse light.

Devon’s mild maritime climate also means extreme cold, which reduces panel efficiency in other parts of the UK, is rarely an issue here. The south-west’s overcast days are a more significant factor than cold temperatures, and a well-designed system accounts for the seasonal variation in its projected output figures.

What about grants?

There is no universal grant for solar panels covering all homeowners. But several routes exist that can reduce the cost or fund an installation entirely depending on your circumstances.

Warm Homes Local Grant: Delivered through Devon’s local councils for eligible lower-income households with poor EPC ratings. Can fund a fully installed solar and battery system at no cost to the homeowner. Availability and waiting times vary by council area.

ECO4: Available for eligible households on qualifying benefits or with low EPC ratings. Runs until December 2026. If you might qualify, acting before the scheme closes is important.

Warm Homes Fund loans: The government has announced low or zero-interest loans for solar, batteries, and heat pumps for homeowners who want to spread the cost rather than pay upfront. These are expected from 2027 and will be usable alongside the Boiler Upgrade Scheme for heat pumps.

Our full guide to the Warm Homes Plan covers the current position in detail.

The honest summary

For most Devon homeowners with a south, south-east, or south-west facing roof in reasonable condition, solar panels are worth serious consideration in 2026. Devon’s irradiance advantage, the 0% VAT position, the SEG income stream, and the post-payback years of effectively free electricity combine to make the financial case stronger here than in most of the country.

The cases where solar is less compelling are real and worth knowing about: north-facing roofs, significant shading, roofs that need replacing, and short expected tenure all affect the outcome. These are not reasons to rule it out without looking, but they are reasons why a survey beats a generalisation every time.

A survey takes around an hour, costs nothing, and gives you a specific answer for your property rather than an average for everyone else’s.

Book a free solar survey in Devon

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