How Much Do Solar Panels Cost in London? Real 2026 Pricing

For a London residential install in 2026, a 3kW system (around 7 panels) typically lands £4,800–£6,500 supplied and fitted. A 4kW system (10 panels) — the most common London size — sits at £6,500–£9,000. A 5kW system (12 panels) runs £7,800–£10,800. A 6kW system (14–15 panels) lands £9,200–£12,500.

All prices include 0% VAT, which remains in force on residential solar PV, battery storage and heat pump installs until 1 May 2027. That single line on your quote saves £1,300–£2,500 against the standard 20% rate depending on system size.

London prices typically run 10–15% above the UK average. Three reasons: scaffold access and parking on terraced streets eats labour hours, roof inspection complexity on Victorian stock, and DNO notification overhead — UK Power Networks paperwork adds 1–3 weeks of installer admin per job that has to be priced in.

Anything quoted under £5,000 for a real 4kW install with a Tier-1 panel brand should be treated with suspicion. The component cost alone — panels, inverter, mounting, cable, isolators, scaffolding day-rate — gets close to that figure before labour. Under-priced quotes typically substitute Tier-3 panels, undersized inverters, or skip the DNO G98/G99 notification.

Panel brand is the biggest single variable. Tier-1 brands (LONGi, JinkoSolar, JA Solar, REC, Trina) carry a 12-year product warranty and 25-year performance warranty. Tier-3 brands carry shorter warranties and a higher field failure rate. A premium panel like REC Alpha Pure-R adds roughly £800 to a 4kW system over a standard JinkoSolar TigerNeo.

Inverter choice is next. A standard string inverter (SolarEdge, SMA, Solis, Growatt) is the baseline. Microinverters or DC optimisers (Enphase, SolarEdge HD-Wave with optimisers) add roughly £600–£1,200 to a 4kW job but handle shaded London roofs significantly better. On a north-aspect or chimney-shaded property, optimisers usually pay for themselves in yield.

Roof type and access drives labour. A standard pitched tile roof with scaffold access to both verges is the baseline. A flat roof requires ballast mounting and adds £600–£1,000. A slate roof needs specialist hooks and adds £300–£500. Conservation areas requiring all-black panels and integrated mounting add £800–£1,500.

DNO export limit is a subtle one. UK Power Networks regions of central London now routinely impose G99 export-limit conditions on systems above 3.68kW. A bolt-on export limiter is £150–£300 of additional kit, but the bigger cost is the longer DNO approval timeline (often 6–10 weeks vs 2 weeks for a G98 notification).

The 0% VAT rate on residential solar PV, battery storage and heat pump installs runs until 1 May 2027. After that, the government has indicated a return to 5% (the pre-2022 reduced rate), although no legislation has yet been laid to confirm.

On a £7,500 4kW install with a £4,500 battery, the saving versus 20% VAT is £2,400. Against 5% VAT it is £1,800. Either way, an install booked and commissioned before 1 May 2027 is materially cheaper than the same install booked in summer 2027.

The 0% rate applies to the install package — panels, inverter, battery, cabling, scaffold, labour — when supplied under a single contract by an MCS-certified installer. Stand-alone hardware purchases (you buying panels online and getting an electrician to fit them later) do NOT qualify. The relief is install-bundle-only.

Practical timing: installers' books for spring 2027 are already filling in mid-2026. If you intend to use the relief, book the survey before the end of 2026 to lock in a Q1 2027 install slot. Leaving it until late 2026 risks pushing into a post-VAT-rise install date.

A 5kWh battery added to a new solar install lands £3,800–£5,500 fitted in London. A 10kWh battery (the common size for a 4-bed family install with an EV) runs £5,500–£8,500. A 13.5kWh battery (Tesla Powerwall 3 or GivEnergy AIO HV) runs £8,500–£12,000.

Adding a battery at the same time as the solar install is materially cheaper than retrofitting one later. Day-rate, scaffold, DNO notification and commissioning are shared overheads. A battery retrofit done as a separate visit 18 months later typically costs £600–£1,000 more than the same battery installed alongside the solar.

The battery economics in 2026 are driven by Cosy / Intelligent / GoElectric overnight tariffs more than by solar self-consumption. A battery on a 7p/kWh overnight tariff, fully charged from grid and discharged during the 4pm–7pm peak, saves £400–£600 a year on a typical London family bill regardless of whether the panels generated anything that day.

The total system economics — solar plus battery plus an EV on Intelligent Octopus Go — usually pay back in 7–10 years on a south-facing London roof. Solar-only without a battery pays back in 8–11 years. Battery-only without solar can pay back in 6–8 years on the right tariff.

The Smart Export Guarantee (SEG) is the post-FiT export mechanism that pays you for surplus solar fed back to the grid. In 2026 the best SEG rates in the UK come from Octopus (Outgoing Octopus, 15p/kWh fixed) and EDF (16p/kWh for Octopus dual-fuel customers). Lower-tier suppliers pay 4–6p/kWh — almost not worth the export.

On a 4kW south-facing London install with no battery, expected annual generation is around 3,400 kWh. Self-consumption typically captures 30–45% (1,000–1,500 kWh used directly). Export to grid is 1,900–2,400 kWh per year. At 15p/kWh SEG, export income is £285–£360/year.

Add a 10kWh battery and self-consumption rises to 70–85%, cutting export and increasing direct bill savings. The total annual financial benefit (savings + export) rises from £750/year (PV-only) to £1,050/year (PV+battery) on a typical London home using 3,800 kWh/year.

Switching SEG supplier is straightforward — your generation MCS certificate and DNO commissioning certificate are the only documents needed. Many homeowners install with one supplier and switch SEG to Octopus or EDF post-commissioning purely for the export rate.

MCS certification is the baseline. Any installer claiming the 0% VAT relief, applying for SEG, or applying for Boiler Upgrade Scheme work must hold current MCS certification under the relevant scheme (PV for solar, Battery for storage, ASHP for heat pumps). Verify the certification on mcscertified.com before paying a deposit.

Three rough installer tiers exist in the London market. National installers (Project Solar, Glow Green, Solarsense) sit at the top of the price band and typically use brand-name kit with extended warranties. Regional installers (Greenmatch, London Solar, Joju) sit mid-band with quality kit and a tighter timeline. Local one-van independent MCS installers sit at the bottom of the price band but have variable kit selection — verify the panel and inverter brands before signing.

Warranty terms are where the headline price hides real differences. A 12-year workmanship warranty plus 25-year panel performance warranty is the modern standard. Some lower-tier installers offer 2-year workmanship only — fine while they are trading, useless if they fold (and many small solar firms have folded since the 2022 boom).

Insurance-backed guarantees (IBGs) are worth checking. An IBG insures the workmanship warranty against installer insolvency. RECC and HIES (Renewable Energy Consumer Code and Home Insulation and Energy Systems) both offer IBG-backed installer schemes. A quote that includes an IBG is materially safer than one that does not, regardless of headline price.

Three further filters separate a good installer from a marginal one: a written heat-loss and shade analysis at survey stage (not a rule-of-thumb sizing), willingness to share the DNO G98 or G99 notification reference number before commissioning, and a fixed itemised quote that names panel and inverter model numbers rather than a generic 'Tier-1 panels and 5kW inverter' description.

Lead-time honesty is the final filter. A reputable installer in mid-2026 has a 6–14 week lead time on a typical 4kW install. Any quote promising next-week installation is either substituting components from clearance stock or is a one-van operator with no current pipeline — both of which deserve careful scrutiny.

Finally, the deposit structure matters. Industry-standard staged payment is 25% on contract signing, 50% on equipment delivery, 25% on commissioning. Quotes asking for 100% up front are a clear red flag — even reputable installers occasionally fold, and the staged payment protects the customer's exposure. A 50%-or-more deposit is unusual; ask for justification before paying.