How much do solar panels cost in the UK?

Three real reasons: panel quality (cheaper Tier-2 panels vs premium Tier-1 like REC, SunPower, LG), inverter brand (SolarEdge optimisers cost more than a single string inverter but handle shade better), and labour rates which vary by region. One reason it shouldn't vary much: the panels themselves are largely commoditised. If one quote is 40% cheaper, ask exactly what kit they're using.

Modestly. Most reputable installers price tightly because solar margins aren't huge — the room to haggle is usually small (5-10%) and often just delays the project. Where quotes are genuinely soft is on extras: extended warranties, remote monitoring, scaffolding-included packages. Better tactic: get 3 honest quotes, pick the installer you trust most rather than chase the lowest price.

Standard quote: panels, inverter, mounting system, DC and AC cabling, isolators, generation meter, scaffolding, installation labour, MCS certification paperwork, DNO notification, and 0% VAT applied. Extras you might see priced separately: bird-proofing mesh, optimisers per panel, additional consumer unit work, longer warranties, battery storage. Ask for the line items.

Often. Solar PV is a regulated trade — installers pay for MCS membership, RECC code-of-conduct membership, NIC certification, public liability insurance, and trained electricians. A quote that's 30%+ cheaper than the rest is usually one of: (a) using cheaper Tier-2 panels, (b) skipping certifications you'll need for SEG, (c) sub-contracting to less experienced labour, or (d) margin-light to win business and cut corners on aftercare. None of those is automatic disqualifier — but ask exactly what corner is being cut.

Most installers ask for a deposit (typically 10-25%) on contract signing, with the balance due on completion or via staged payments tied to delivery and installation milestones. Avoid 100% upfront payment requests — that's a known scam pattern. RECC member companies follow set deposit rules.

Sometimes. Most "no upfront cost" offers are loans, not grants — you'll repay over 5-15 years, often at higher rates than a standard mortgage drawdown. Worth doing the cash maths: a 6% finance rate on a £6,000 system means you pay ~£8,500 over 10 years vs £6,000 cash. If your savings rate is lower than the loan rate, finance is fine; if you can pay cash, cash is cheaper.

Three common ones: (1) scaffolding for awkward access roofs (steep pitch, listed-building rules, 3-storey terraces) can add £400-£1,000 versus a simple 2-storey detached. (2) Older consumer units that need upgrading to be solar-compatible — £500-£1,200. (3) Roof condition issues found on the day — slipped tiles, rotten battens. Reputable installers check on the survey to avoid surprises.