Commercial solar surveys in London

Key facts for commercial solar in London

Who runs the network in London

UK Power Networks operates the electricity distribution network across Greater London. Central London sits in its London licence area, while many outer boroughs fall within its Eastern or South Eastern areas. Licence boundaries do not follow borough or county lines exactly, so confirm the operator for your postcode with the Energy Networks Association postcode tool before you rely on anything else.

Very few commercial systems are small enough for G98 (up to 16A per phase, about 11.04 kW on a three phase supply), so most London projects need G99 approval before connecting. In a dense urban network, the capacity of the local substation and technical limits such as fault level can shape the offer you receive. Where full export is not available, an export limitation scheme under G100 can let a larger array connect while capping what it sends to the grid. Our G99 and DNO applications guide explains the process.

Import capacity matters as well. In 2022 the Greater London Authority warned that electricity capacity in parts of west London was constraining new development. If your plan includes EV charging or a battery that raises your import, the survey should flag whether a supply upgrade is likely.

How much a London roof produces

We modelled a 1 kWp array in central London in PVGIS (version 5.2, SARAH2 solar data, 14% system losses). Facing south at the optimum tilt of about 40 degrees it gives roughly 1,020 kWh a year. An east-west layout at 10 degrees, typical on a flat roof, gives roughly 840 kWh. Most real London roofs sit between those figures and often lower, because neighbouring buildings, parapets, lift overruns and rooftop plant cast shade for part of the day. Treat the range in the table as indicative; a survey models your actual roof.

Planning and policy in London

The national rules for England apply. Permitted development rights for non-domestic rooftop solar were widened in December 2023, including removal of the old 1 MW limit, but conditions still apply. London has a high concentration of conservation areas and listed buildings, where those conditions bite hardest, so check early. Our planning permission guide sets out the conditions.

The London Plan

The London Plan 2021 is the main policy that sets solar apart in the capital. Policy SI 2 expects major developments (for commercial schemes, generally 1,000 square metres or more of new floorspace) to be net zero carbon, with at least a 35% on-site reduction in regulated emissions beyond Building Regulations. It follows an energy hierarchy: be lean, be clean, be green and be seen. Any shortfall is usually met by a payment into the borough's carbon offset fund, and the "be seen" step requires energy performance to be monitored after occupation.

For an existing building that is not undergoing major development, the London Plan does not require you to fit solar, though individual borough policies vary. For a refurbishment or extension that counts as major development, rooftop PV is often one of the more practical ways to meet the "be green" stage.

The Mayor published a draft new London Plan on 16 July 2026. Consultation closed on 15 October 2026 and examination is expected in 2027. Until a new plan is adopted, the 2021 plan remains in force, so check whether the energy policies change at examination.

ULEZ and the Congestion Charge

The Ultra Low Emission Zone has covered all London boroughs since 29 August 2023. The Congestion Charge exemption for electric vehicles ended on 25 December 2025; electric vehicles registered for Auto Pay now get a discount rather than paying nothing. Both changes push fleet operators towards electric vans and cars, and daytime depot charging pairs well with rooftop generation. See EV charging for business.

London's commercial building stock

London's industrial land is concentrated in places such as Park Royal in the west, the Lea Valley, and the Thames-side and Royal Docks areas in the east, along with the logistics belt around Heathrow. Many of these sites are multi-let estates, so the roof owner and the electricity user are often different businesses. That makes the lease, the landlord's consent and who benefits from the power central to the project; our page for commercial landlords covers the options.

Offices, schools, hospitals and retail make up much of the rest. Office roofs in London are often small relative to the building's electricity demand, so nearly all generation is used on site, which helps the payback even where the array is modest.

Support and finance in London

London businesses use the same national schemes as the rest of England: capital allowances, the business rates exemption for eligible onsite generation and storage plant (to 31 March 2035), and the Smart Export Guarantee for exported power. See grants and support in England, and confirm tax treatment with your accountant.

How the free survey works in London

You complete the short form and we call to understand the building, the lease and your electricity use. If the site looks suitable, we arrange a free survey with one MCS certified installer matched to the site. In London a virtual first look using drawings, aerial imagery and your half-hourly data is common, followed by a roof visit once building management and access are agreed. Your details go to that one installer only, and there is no obligation to proceed. See how a survey works.