Are Solar Panels Worth It?

Author: Steve Fairless
Originally Published: 17th December 2023 · Updated: 28th August 2026

For many suitable UK homes, solar panels are still worth it in 2026 — but the answer depends on system price, annual generation, self-consumption, export tariff, roof quality and how long you expect to own the system. Current Energy Saving Trust data puts a typical 4.5 kWp domestic installation at about £7,600 and shows example payback periods of roughly 9-12 years across several Great Britain locations when export payments are included.

At Sustainable Energy Engineering, we do not define “worth it” as the shortest possible headline payback. A good solar investment should also have credible generation assumptions, suitable equipment, safe roof and electrical design, realistic maintenance allowances and a configuration that fits how the household actually uses electricity.

Updated: 28th August 2026 using current Energy Saving Trust, Ofgem, HMRC, MCS, DESNZ and Warm Homes Plan evidence.

What Does “Worth It” Actually Mean?

There are at least four different answers:

• Bill savings: how much grid electricity the system replaces.
• Export income: how much surplus electricity earns through a tariff.
• Long-term return: whether lifetime benefits justify the capital and maintenance cost.
• Non-financial value: lower carbon emissions, greater energy autonomy and compatibility with EVs, batteries or heat pumps.

A household can value all four differently. That is why we prefer a transparent model rather than a one-line promise such as “solar pays back in six years”.

Current 2026 Cost and Payback Benchmarks

Energy Saving Trust's current consumer guidance uses an average domestic system size of roughly 4.5 kWp and an installation cost of around £7,600. It says panels should last 25 years or more, while an inverter may need replacement after around 12 years.

Its July 2026 payback table, including export payments, gives the following examples:

Those figures are a strong national benchmark, but Energy Saving Trust itself cautions that its statistics should not be used as bespoke financial modelling. A real proposal should model the actual property.

Why Every Self-Used kWh Can Be More Valuable Than an Exported kWh

Ofgem's July-September 2026 cap gives an average electricity unit rate of 26.11p/kWh for Direct Debit default-tariff customers. Energy Saving Trust says a typical SEG export payment may be around 12p/kWh, although export tariffs vary.

Using those values, a self-used solar unit can be worth more than twice the exported unit. That is why load matching matters.

Illustrative Annual Value at Different Self-Consumption Levels

Assume 3,600 kWh annual generation, a 26.11p avoided import price and a 12p export tariff. This is illustrative only and ignores degradation, standing charges, tariff changes and maintenance.

The calculation shows why two identical arrays can have different financial outcomes on two different households.

What MCS Performance Modelling Shows About Self-Consumption

The current MCS Solar PV Installation Standard, MIS 3002 Issue 6.0, requires installers to provide an annual generation estimate using its prescribed performance-estimation method and to calculate expected self-consumption using the referenced MCS methodology. That matters when judging an investment because a credible proposal should be based on the property, system design and likely energy use rather than a generic savings promise.

That is an MCS worked example — not a promise that every 9 kWh battery will transform every home from 29% to 82%. The point is that storage value depends on the relationship between generation, household load and usable battery capacity.

Is a Battery Worth Adding?

Energy Saving Trust currently says battery storage tends to cost around £5,000-£8,000. That is substantial compared with the £7,600 solar benchmark, so we treat the battery as a separate investment decision rather than assuming “solar plus battery” is always the best package.

A battery can be compelling where the household has significant evening load, regular solar surplus, a useful time-of-use tariff, or a resilience objective. It can be weaker where most solar is already used directly or where the array is too small to cycle a large battery consistently.

Our solar battery storage guidance explains how storage fits into a complete system.

SEG Export Payments Are Still Part of the Economics

Ofgem's Smart Export Guarantee framework means eligible small-scale solar generators in Great Britain can receive payment for exported electricity. The regulator publishes a current licensee list each SEG year, while the actual rate and contract are set by the supplier.

Do not build a 20-year cashflow using today's best export tariff as though it were guaranteed for 20 years. Tariffs can change, suppliers can change their offers and the value of self-use can change with electricity prices.

0% VAT Is Still in Place — For Now

HMRC's July 2026 guidance states that qualifying energy-saving materials installed in residential accommodation, including solar panels, are subject to 0% VAT until 31 March 2027.

That is one reason the current upfront economics are different from older articles written before the zero-rating period.

Government Support Is Changing Again

The 2026 Warm Homes Plan sets out a major expansion of home-upgrade support, including solar panels and batteries. It describes £15 billion of public investment across home upgrades and a new low- and zero-interest finance offer.

However, policy announcements and consumer availability are not the same thing. The Warm Homes Loan Scheme opened to lenders in 2026, with the first lender-application tranche later closing and further windows expected. We therefore would not tell a homeowner that a universal cheap solar loan is already available to them without checking the live consumer offer.

Solar Adoption Is Accelerating, But Popularity Is Not Proof of ROI

DESNZ reported on 27 August 2026 that nearly 172,000 solar installations had been fitted across the UK since the start of 2026, with more than 19,800 rooftop installations in July alone. Solar installations increased in every UK nation and English region over the prior 12 months.

That is strong evidence of market adoption. It is not evidence that every roof is suitable. We still need engineering and financial due diligence at property level.

When Solar Is Usually a Stronger Investment

What About Roof Direction?

South-facing unshaded roofs typically maximise annual generation, but east- and west-facing roofs can still make sense. Energy Saving Trust currently says east- or west-facing systems tend to produce around 15-20% less energy than a directly south-facing system.

That does not automatically mean worse economics, because an east/west profile may align more closely with morning and late-afternoon household demand. Our domestic solar PV design approach looks at the profile as well as the total annual kWh.

What About Roof Condition and Maintenance?

A solar array can remain on a roof for decades. If the roof covering is close to end of life, dealing with it before installation can avoid paying later to remove and refit the array for roof repairs.

Energy Saving Trust says solar panels should last 25 years or more and that tilted UK panels often benefit from rain cleaning. The inverter may need replacement sooner, which should be allowed for in long-term ownership costs.

Does Solar Increase Property Value?

Solar can improve running-cost appeal, but there is no guaranteed universal house-price uplift that should be included as cash return in a payback model. Buyers and lenders may care about ownership structure, warranties, system condition and documentation.

We would treat any future property-value uplift as a possible secondary benefit rather than the core reason the system is “worth it”.

Ten Questions to Ask Before Calling Solar a Good Investment

Our View: Solar Is Worth It When the Numbers Are Property-Specific

The current evidence is favourable: solar costs have a credible national benchmark, grid electricity remains expensive, SEG provides an export route, VAT is currently zero-rated and panels can deliver decades of generation. But none of those facts justify a poor design.

The best investment is not automatically the system with the most panels or the biggest battery. It is the system that converts a suitable roof and the household's real electricity demand into a strong, defensible lifetime result.