Commercial Solar Grants London | Greater London 2026

Commercial solar funding in London — what’s specific

London is unusual among UK commercial solar markets. The city has the highest electricity unit rates in the country, the largest number of operationally suitable buildings, and the most complex distribution network. It also has the most concentrated public sector estate eligible for Salix Phase 4 — Bart’s Health alone runs 12 sites with 950,000 m² of estate, all PSDS-eligible. But London also has constraints: planning sensitivity in 32 boroughs, listed-building density in central zones, and DNO connection costs that have risen sharply on the UK Power Networks (UKPN) network since 2024.

For commercial solar grant purposes, London splits into three distinct sub-markets.

Inner London (Zones 1–2). Dominated by listed and conservation-area buildings. Most rooftop solar applications are limited or refused under listed building consent. The viable answer is either solar canopy on car parks (rare in central London), off-site sleeved PPAs, or PV on adjacent service buildings. The exceptions are large institutional estates with non-listed buildings — UCL, KCL, Imperial College and the major NHS trusts have substantial PSDS-funded PV programmes underway.

Outer London and inner suburbs (Zones 3–6). The strongest economics in London. The Park Royal Industrial Estate, Charlton, Croydon, the Royal Docks Enterprise Zone, the Old Oak Common HS2 hub area and the Kingston-Sutton industrial belt all have substantial roof inventory on post-1990 industrial and logistics buildings. Most projects in outer London are 200kWp to 1.5MWp on individual sites, with PPAs and the Annual Investment Allowance as the dominant funding routes.

Greater London commercial estates and freeport. The Royal Docks Enterprise Zone has solar-priority funding through the Mayor’s Solar Skills London programme, separate from national IETF/PSDS. The Thames Freeport (covering DP World London Gateway and Tilbury) has its own freeport tax incentives that sit alongside the Annual Investment Allowance for assets located within the freeport boundary.

How DNO connection works in London

UK Power Networks operates London’s electricity distribution network. The network is among the most heavily loaded in the UK, particularly in inner east London (Tech City, Stratford, Canary Wharf), south Bermondsey, and the Royal Docks. Solar export above 16A per phase requires a G99 application and, increasingly, an export-limited connection (G100) where peak export is constrained below the array’s peak generation.

Three pieces of London-specific DNO knowledge that affect project economics:

• Active Network Management (ANM) zones are now live across most of east London and parts of south London. ANM zones avoid network reinforcement costs but introduce export curtailment risk that has to be modelled.
• DUoS charges in central London are among the highest in the country — typically £85–£110/MVA/year vs £55–£75/MVA/year in regional networks. This affects the savings model for any sites with material peak demand.
• Substation upgrade timelines can be 18–30 months in heavily loaded areas. We always check the local network position before scoping any project above 250kW in London.

Public sector funding in London

The PSDS opportunity in London is large but politically and operationally complex. The 32 London boroughs have widely different decarbonisation maturity. The most active under PSDS Phase 4 in our experience: Camden (estate-wide retrofit programme since 2022), Lambeth (substantial schools rollout), Hackney (council-owned commercial property), Croydon (large schools estate), and Tower Hamlets (multi-year capital programme through Phase 4).

Bart’s Health, Guy’s & St Thomas’, King’s College Hospital, Imperial College Healthcare and University College London Hospitals together control more than 5 million square metres of NHS estate in London — almost all PSDS-eligible and at varying stages of solar deployment.

The Greater London Authority operates separately under its own decarbonisation budget and has 100% funded several solar projects on the GLA estate (City Hall, Queen Elizabeth Olympic Park, TfL depot estate). GLA-managed PV is particularly visible at Olympic Park, where 1.4 MWp is now installed across ArcelorMittal Orbit, the London Stadium support buildings and the Lee Valley sports facilities.

What private sector commercial PV looks like in London

The fastest-growing London market is logistics and Big Box retail in outer zones. Park Royal alone has hosted 14 commercial PV projects above 250kWp in 2023–25, mostly on logistics and food-production buildings. The Old Oak Common HS2 development area is being designed with PV-ready specifications.

Data centres are an emerging market within London. Despite the constraint on building-mounted PV (most data centre roofs are dominated by chillers and dry coolers), several London-area operators have signed sleeved PPAs for off-site UK ground-mount PV that is contractually allocated to London demand. This is becoming the standard funding mechanism for data centre solar exposure in space-constrained markets.

For office buildings, the financial case is tighter. Class A central London offices typically have heavily occupied roofs (plant, PR antennae, MEP) and the savings on a 200–500 kWp install rarely justify capex against alternative property value uplift. The exception is BREEAM Outstanding and Net Zero Carbon Buildings Standard certifications, where PV is a credit-earning measure and the cost is justified by certification value rather than energy savings.

How we work with London clients

Our office is at 71-75 Shelton Street, Covent Garden, ten minutes’ walk from Covent Garden tube. London projects are usually scoped via a 30-minute video call followed by a site visit within the same week. Most London engagements are funded via AIA alone (private sector) or PSDS (public sector and NHS). For multi-site groups, the scoping workshop covers a property list assessment with the head of estates and the operator’s procurement lead.

The free funding review is the fastest route. For NHS or large public estate enquiries, ask for Priya. For private sector projects above £500k, ask for Daniel.

Grid connection for commercial solar in London

UK Power Networks (UKPN) is the distribution network operator for London and Greater London. Understanding UKPN’s connection criteria is essential before finalising system size and export configuration on any London commercial solar project.

G99 application timelines in London: UKPN is currently processing G99 applications in 75–95 working days for sub-500kW projects. Larger projects (500kW–1MW) typically require 4–6 months and a formal connection study. Projects above 1MW require a full distribution reinforcement assessment and typically 6–12 months to connection agreement.

Export limitations: Many urban and industrial substations in London have constrained export headroom. Before designing a system, we run a pre-application capacity check through UKPN’s online tool and, for projects above 200kW, a direct pre-application discussion with the connections team. This prevents the most common error we see on London projects: contractors quoting for a system size that UKPN won’t accept.

Active Network Management (ANM): Several London substations operate under ANM — where the DNO can curtail your export during grid constraint events. We model the economic impact of ANM curtailment risk as part of every London solar assessment. In practice, the majority of London commercial sites achieve export acceptance without curtailment, but this is always verified before commitment.

Battery storage and EV charging connections: For London sites co-locating solar PV with battery storage or EV charging, we coordinate a single combined G99 application to UKPN. This avoids the cost and delay of multiple separate connection applications. The DNO connection cost for a combined PV + BESS project is typically 10–15% lower per kW than two separate connections.

Behind-the-meter systems: Where London sites prefer a fully behind-the-meter system (no grid export), G99 application can be simplified or avoided entirely. We design export-limited systems for London sites where connection headroom is limited or where the commercial case is stronger from maximising self-consumption rather than export.

Commercial property market in London

London’s commercial property market creates a distinctive solar opportunity. Average commercial rents of £72/sq ft prime, £28/sq ft outer London industrial reflect the city’s standing in the UK property hierarchy and the type of occupiers operating in the area.

• Listed and conservation-area heritage buildings (typically off-limits to rooftop PV — sleeved off-site PPAs the workable route)
• Big Box logistics in Park Royal, Charlton, Royal Docks (1.4MWp+ rooftop projects, PPA-funded)
• Multi-academy trust school estate (PSDS Phase 4 candidates across boroughs)
• NHS estate — Bart’s Health, Imperial, Guy’s & St Thomas’, UCLH (PSDS Phase 4)
• Higher education: UCL, KCL, Imperial, LSE, Queen Mary, Goldsmiths

For solar funding purposes, the property type matters significantly. Owner-occupied sites have the simplest funding structure — AIA, 0% VAT and SEG all apply directly to the occupier. Leasehold sites require landlord consent and typically a legal licence to occupy roof space, but this is standard practice and rarely a blocking issue in London. The landlord-tenant dynamic for solar in London varies — some landlords actively co-invest in solar to improve EPC ratings and asset value; others are passive and simply grant licence.

Roof condition and age: The majority of commercial and industrial stock in London built post-1985 is suitable for rooftop solar without structural strengthening. Pre-1980 stock — particularly multi-story concrete frame buildings — requires a structural survey, which we arrange as part of the feasibility stage. Asbestos cement roofing is present on a minority of older London industrial units; this requires encapsulation or removal before PV mounting, which we manage as part of project delivery.

Planning: Most London commercial rooftop installations under 1MW qualify as permitted development and require no planning consent. Ground-mount systems, building-integrated PV, and installations on listed buildings or within London’s conservation areas require full planning permission. We prepare planning applications and liaise with the relevant local authority as standard.

Grant eligibility by sector in London

The London economy spans London commercial operators. Grant eligibility varies significantly by sector:

• Annual Investment Allowance (AIA): Available to all London businesses. The broadest and most accessible route, applicable to any commercial solar installation — solar is special-rate expenditure (HMRC CA22335), so AIA, not Full Expensing, is the 100% year-one allowance.

Manufacturing and industrial occupiers in London: The most grant-rich sector. IETF Phase 3 is closed, but the Annual Investment Allowance gives 100% first-year tax relief on the first £1m of solar capex with no application process (solar is special-rate expenditure, so AIA — not Full Expensing — is the route). Manufacturing tenants on London’s industrial estates typically achieve the fastest internal payback because their daytime electricity demand is highest and most consistent.

Retail and commercial occupiers in London: AIA and 0% VAT apply. SEG export income is available where roof area exceeds on-site consumption capacity. PPA structures work well for London retail parks and shopping centres where landlords want zero upfront capex.

Public sector in London: NHS trusts, local authority buildings, schools and universities access Salix Finance interest-free loans for solar, battery storage and heat pump projects. PSDS Phase 4 has closed but Salix BAU loans are open-ended and continuously accepting applications for Greater London public bodies.

Hospitality, leisure and food service in London: Daytime solar generation aligns well with peak consumption profiles. AIA applies to incorporated operators, sole traders and partnerships alike. Holiday parks and leisure centres may also access the Great British Energy Community Fund for community-facing installations.

Battery storage, EV charging and heat pumps in London

Commercial solar in London is increasingly the anchor of a broader clean energy package rather than a standalone measure. Three complementary technologies amplify the value of a London solar installation significantly:

Battery storage in London — Commercial battery storage paired with rooftop solar increases self-consumption from approximately 55–65% to 80–90% on typical London commercial sites. Battery systems qualify for AIA (same rules as solar) and 0% VAT when co-located with PV. For London businesses on time-of-use tariffs, battery arbitrage between off-peak charging and peak discharging delivers an additional £5–15k per year per 100 kWh of storage. London’s grid operator processes a single combined G99 application for solar + battery, reducing connection cost and lead time.

EV charging in London — EV charging points at London commercial sites integrate naturally with rooftop solar. Smart charge controllers shift vehicle charging to solar generation hours, reducing effective EV fuel cost to near-zero during daylight hours. The OZEV Workplace Charging Scheme (up to £14,000 per site) and fleet depot EVIG grants (up to 75% of installation cost) reduce the capital cost of EV infrastructure significantly. Co-locating solar + EV + battery in a single London project application qualifies for 0% VAT across all three assets simultaneously.

Heat pumps in London — Commercial heat pumps replace gas boilers at 3.5–5× the efficiency of direct electric heating. For London buildings with continuous heating demand — offices, leisure centres, healthcare, hospitality — a solar-powered heat pump delivers heating at a marginal cost of 1–2p/kWh effective (solar electricity divided by CoP). NHS trusts, schools and councils in London access Salix Finance interest-free loans for heat pump installations.

Energy efficiency packages — Bundled energy efficiency packages combining all four measures — solar, battery, EV, heat pump — qualify for the maximum available grant stack: the Annual Investment Allowance on all assets, 0% VAT on qualifying measures, OZEV grants on EV chargers, and Salix loans for public sector elements. Bundling reduces contractor mobilisation cost and allows a single G99 application to the local DNO.

How we work with London clients — a typical project

A typical London commercial solar project follows a consistent process from initial enquiry to energisation. Understanding the timeline helps clients plan board approval, contractor procurement and financial forecasting accurately.

Week 1–2: Free funding review and desktop assessment. We gather utility bills, roof drawings (or use Google Maps/Ordnance Survey data for initial sizing), and the relevant company registration details. We run the funding stack — which grants apply, what the 0% VAT status is, whether IETF or Salix routes are accessible — and return a written funding shortlist within one working day of receiving data.

Week 2–4: Site survey and technical design. An MCS-accredited surveyor visits the London site. Structural loading assessment (if required), roof condition inspection, shading analysis, and AMR data interpretation. The survey produces a preliminary system design: panel count, inverter specification, and G99 export limit for submission to the local DNO.

Week 4–8: DNO pre-application and formal connection offer. We submit a G99 pre-application to the DNO and receive a formal connection offer within the stated lead time. For London sites requiring reinforcement, we negotiate the lowest-cost connection route and incorporate this into the financial model.

Week 6–10: Grant application (where applicable). Where IETF, Salix, or REPF routes apply, we draft and submit the application concurrently with DNO pre-application. The Annual Investment Allowance and 0% VAT require no formal application — they are applied by the contractor at invoice stage.

Week 10–16: Contractor procurement and installation. We manage tender, contractor selection, and programme management. A typical London rooftop installation of 100–500kWp takes 3–5 days on site. Commissioning, G99 notification, and MCS certificate follow within two weeks of energisation.

Total typical project programme from survey to energisation: 12–20 weeks depending on system size and funding route. The free funding review form is the fastest way to start — we respond within one working day.