Compare Solar Panel Quotes: What to Look For in 2026 UK
In 2026 UK, two solar quotes for the same roof can differ by £1,500–£2,500 on a 4kWp system. The headline price hides the real spec: panel wattage (430W vs 480W), inverter brand (SolarEdge, Enphase micros, Fronius string), MCS certification, performance warranty (25 vs 30 year), and whether scaffolding, DNO G99 commissioning and an iBoost diverter are included. Use this 2026 checklist to spot the difference.
The 6 fields that matter on a solar quote — 2026 UK
- Panel model & wattage — e.g. JA Solar 440W vs JinkoSolar 480W (£300–£500 swing on 10 panels)
- Inverter brand and topology — string (Fronius, Solis), hybrid with battery port (SolarEdge, GivEnergy), or micro-inverters (Enphase IQ8)
- MCS certificate number — must be present, must match the installer's name on the MCS database
- Performance warranty — 25 years at 84.8% (tier-2) vs 30 years at 87.4% (tier-1) is a real £ difference in lifetime yield
- Scope of works: scaffolding, DNO G99 commissioning, iBoost / Eddi diverter, bird mesh, isolators
- Battery option: kWh, brand (GivEnergy / Tesla / Fox), warranty (cycle count), VAT 0% confirmation
2026 indicative 4kWp price: £5,200–£6,800 (panels + inverter, no battery). With a 5.2kWh GivEnergy battery: £9,400–£11,200. 0% VAT on residential domestic solar continues to 2027.
Side-by-side solar quote comparison table — 2026 UK
2026 red flags in solar quotes (and how to call them out)
- No panel model / wattage on the quote — ask for a manufacturer datasheet before signing. "6 panels" without watts means nothing.
- “MCS pending” or no certificate number — you cannot claim 0% VAT or SEG export without a fully MCS-certified install. Walk away.
- Inverter model unspecified — budget installers swap brands week-to-week. Demand the exact model in writing.
- Workmanship warranty under 2 years and no IWA — a HIES or RECC insurance-backed warranty protects you if the installer goes under. £80–£120 to add if missing.
- Battery without VAT 0% declaration — from Feb 2024, batteries fitted at the same time as solar are 0% VAT. Standalone retrofits are 0% VAT too from 1 Feb 2024. Insist this is on the quote.
- “SEG export not included” disclaimers — the export tariff is set by your supplier, not the installer, but the installer must lodge the MCS certificate that lets you sign up. Confirm the certificate will arrive within 10 days of commissioning.
- Performance guarantee < 84% at year 25 — a sub-tier-2 panel; lifetime yield will lag.
String vs Hybrid vs Micro-inverter (2026 UK)
Frequently asked questions
Three is the sweet spot — enough variation to spot outliers, not so many that comparison becomes unwieldy. All three must be MCS-certified installers. If you only get two, you can't tell whether the lower is suspicious or the higher is over-spec.
The Microgeneration Certification Scheme certifies the installer (not the kit). Without an MCS-certified install you cannot register for the Smart Export Guarantee (SEG) and may not qualify for 0% VAT. Always verify the certificate number against the installer's name on mcscertified.com.
480W (REC Alpha, Q.PEAK, LONGi Hi-MO 7) gives 10–12% more output per panel and is the right call for small roofs where panel count is constrained. On large roofs the cheaper 430W generates equivalent annual yield at a lower up-front cost. 480W warranties are typically stronger.
Yes. The 0% VAT rate on domestic solar PV (and on standalone batteries from Feb 2024) is in force to 31 March 2027. After that the rate is due to revert to 5%. Quotes must show the 0% VAT explicitly on the breakdown.
Below 3.68kW per phase you can self-notify under G98 within 28 days. Above 3.68kW (most modern 4kWp+ systems) you need a G99 application before install. Reputable installers submit this for you and confirm DNO acceptance before scheduling commissioning.
For typical 4kWp solar + 5kWh battery the payback in 2026 is 8–11 years assuming SEG export at 15p and time-of-use import on Octopus Cosy or Intelligent Octopus Go. A 0% VAT install lowers payback. If you're rarely home during the day, battery pays for itself faster.
Sources used
- MCS — Find a Contractor
- Ofgem — Smart Export Guarantee
- gov.uk — 0% VAT on energy-saving materials
- ENA — G99 / G98 connection process
- HIES — Home Insulation & Energy Systems consumer code
Methodology: Quote-comparison spreads use representative data from BestBuilders' UK MCS-certified solar installer network (May 2026, 210+ vetted installers). Kit pricing cross-referenced against trade-counter and direct manufacturer pricing. Last fact-checked: .