How to Avoid Solar Sales Traps in the UK

Solar can be a genuinely good investment in the UK — or a costly mistake, depending on your roof, your electricity use and your tariff. The problem is that most of the advice you'll hear comes from someone who only earns money if you sign. This guide walks through the four most common sales traps, how to test the claims yourself, and where the numbers really come from.

Trap 1: Pressure selling and the "today only" discount

The classic close: a salesperson spends two hours at your kitchen table, then reveals a headline price and a "discount that expires tonight". Solar is a fixed asset on your roof for 20-plus years — there is no honest reason a fair price should evaporate at midnight.

• Any genuine quote is valid for days or weeks, not hours.
• A £13,000 decision deserves at least two or three written quotes to compare.
• Walk away from anyone who won't leave the numbers with you in writing.

Installed prices in the UK sit in broad ranges — roughly £6,500–£9,500 for a 4 kWp system, £9,000–£13,000 for 6 kWp and £11,000–£16,500 for 8 kWp. If a "discounted" price still sits at the top of that range, the discount was never real.

Trap 2: Inflated SEG export promises

The Smart Export Guarantee (SEG) pays you for electricity you export to the grid. It's retailer-set and volatile — across the market it runs from about 4p to 16.5p per kWh. A standalone SEG rate can be as low as around 4.1p/kWh, while a flat export tariff like Octopus Outgoing sits nearer 12p/kWh. Time-of-use tariffs such as Intelligent Octopus Flux can pay more at peak — but require a battery.

The trap is a salesperson modelling your payback on the highest export rate on the market, then assuming you export most of what you generate. In reality the money is in self-consumption — using your own solar avoids buying grid electricity at around 24.67p/kWh, worth far more per unit than any export payment. Typical self-consumption savings land at roughly £400–£700 a year.

Two honest tests for any SEG claim:

• Which specific tariff and rate is assumed — and is it the standalone rate or a premium one you'd have to switch to?
• Remember your export tariff can come from a different supplier than your import, and rates change with 30 days' notice. Verify the current figure before you trust any payback.

Trap 3: The oversized system

Bigger arrays mean bigger invoices, so there's a built-in incentive to sell you more panels than you can use. But every kWh you export earns you a few pence, while every kWh you self-consume saves you around 24.67p. Oversizing pushes more of your generation into low-value export.

There's also a technical ceiling. Systems up to 3.68 kW per phase qualify for simple G98 notification. Above that you need a G99 application to your DNO, and larger single-phase systems are often export-limited to 3.68 kW anyway — so a chunk of that extra capacity may never leave your property for payment.

Size to your actual annual consumption and your daytime usage pattern, not to your roof's maximum. As a rough regional guide, a UK panel yields around 850 kWh per kWp a year (roughly 900–1,000 in south England, 800 in the north, 750–800 in Scotland).

Trap 4: Bundling a battery you may not need

Batteries carry 0% VAT on supply-and-install until 31 March 2027 (including standalone retrofit), which makes them easier to sell. But there's no household grant for a battery, and typical payback runs about 7 to 12 years — with installed costs around £3,500–£5,000 for 5 kWh and £6,500–£9,000 for 10 kWh.

A battery pays only if the tariff maths works: self-consuming more solar, charging cheaply overnight on a smart tariff and discharging at peak, or unlocking a premium export tariff that requires storage. That case is entirely tariff-driven — so it hinges on your actual plan, not a generic model.

Here's the honest catch: for some homes — north-facing roofs, low daytime use, or a modest, cheap grid tariff — solar, a battery, or both simply won't pay back in a reasonable time. A commission-paid salesperson will never tell you that. We might.

Why independent advice pays

Every "free" quote is paid for by the sale. Even comparison sites that call themselves free are paid by the installer they refer you to. We sell and install nothing, and we take nothing from any installer — we charge a small fixed fee (£150 residential) for engineered advice based on your bill, roof and usage.

What honest analysis actually needs from you:

• Your real unit rate, standing charge and tariff — read off your latest bill, not the Ofgem cap.
• Your annual consumption and how much falls in daylight hours.
• Your roof orientation, pitch and shading.
• The specific SEG and smart tariff you'd realistically switch to — verified at today's rates.

On a five-figure decision, paying a fixed fee for numbers with nobody's thumb on the scale is usually the cheapest line on the whole project.

We don't sell panels, batteries or heat pumps, and we're not paid a penny by anyone who does. If the honest answer is "this won't pay for your home," that's the answer you'll get — because our fee is the same either way.

Figures in this guide are current at the date of publication and indicative only — SEG/export rates change with 30 days' notice, the Ofgem price cap resets quarterly, and grant terms change. Confirm the current numbers for your situation before you commit. This is general information, not personal financial advice.