Mayor of London
Zero Carbon Accelerator
Solar for Social Housing · Decision Tool
Zero Carbon Accelerator · July 2026

Solar & batteries for
council and social housing

This is a tool to help landlords understand the decisions they need to take when designing a Solar PV project — in particular when they are seeking to access additional investment. Whether you're looking at a single building, a pilot project, or a whole portfolio, it helps you find the right financing and delivery route.

⚠ Please read before using this tool — July 2026
  • This is an emerging market with models which are evolving. Provider offers, finance routes, and regulation are all changing rapidly. Always verify directly with providers and take advice before commitment.
  • This is a guide, not a recommendation. Outputs are starting points based on the information you provide and the Zero Carbon Accelerator's current view of the market — not a substitute for professional financial, legal, or procurement advice.
  • Pathways are not exclusive. Most landlords will move between pathways as circumstances change (e.g. starting with a partner-led pilot, then moving to ownership at scale).
  • This is a point-in-time snapshot, not a continuously updated tool. It reflects market conditions, provider offers and regulation as understood in July 2026, and will need to be updated as these change. Feedback is welcome — see the About page for contact details and acknowledgements.

Three main pathways

Most landlords will find their situation best described by one of these three routes. Each card sets out the typical steps in the procurement process for that pathway. Use the decision tool to confirm which is right for you.

Note: Pathways 2 and 3 can also be delivered with a licensed energy company acting as the operator — the operator role isn't limited to specialist billing providers.

1
Turnkey: partner funds & operates
Off-balance sheet · Full outsource

A single partner finances, installs, and operates everything. The partner owns the assets and recovers investment through resident energy revenues. No landlord capital required — but if you have a grant or partial budget, this can be used as leverage to secure better commercial terms or a blended structure where you retain more revenue upside.

Steps in the procurement process
  • 1Define homes, volume & resident outcome targets
  • 2CFO/S151 sign-off on off-balance sheet treatment
  • 3Run a mini-tender to turnkey operators if a framework is available, or a full tender if not (a sector-wide framework is being considered to enable easier procurement of these offers)
  • 4Provider produces investment-grade business case
  • 5Final approval & contract
Best for: No capital or off-balance sheet requirement · Minimum scale needed · Appetite (and capacity) for novel contractual structures · Partners: Emergent, Sero, Metis
2
Own the assets, procure an operator
On-balance sheet · Capital + services

Landlord funds the installation (HRA, PWLB, NWF or grant) and owns the assets, and procures a specialist to manage resident billing, grid services, and maintenance. Where a financial return is required, we advise procuring the operator first — their requirements will impact on the system specification. The operator can also deliver supply and install as a single contract, or supply & install can be procured separately if linking to re-roofing or other programmes. An energy company can also act as the operator under this pathway.

Steps in the procurement process
  • 1Confirm capital source (grant, HRA, PWLB, NWF)
  • 2Procure operational services provider first — they set the technical spec
  • 3Option A: Operator also delivers supply & install (one contract, simplest)
  • 3Option B: Procure supply & install separately — e.g. via re-roofing or Decent Homes programme
  • 4Agree service contract, risk allocation & revenue share
  • 5Run a pilot at a defined scale; scale up with evidence
Best for: Capital or borrowing available · Want asset ownership · Outsource complex operations · Partners: Sero, Emergent, Octopus, Energy Local
3
Landlord installs & manages directly
Grant or own capital · Simple or service charge model

The landlord funds and installs solar using grant and/or own capital, and manages the outcome directly. This can mean passing 100% of savings to residents (no revenue collected), or collecting a modest service charge to recover investment. No complex third-party operational model required.

Steps in the procurement process
  • 1Confirm funding (WH:SHF, SHDF, HRA, Decent Homes)
  • 2Decide: 100% savings to residents, or service charge to recover costs?
  • 3Consider combining with re-roofing/Decent Homes works
  • 4Procure supply & install via standard works contract
  • 5If service charge: complete S.20 consultation; set charge below actual saving
Best for: Grant-funded programmes · Landlords wanting direct control · Simple billing preferred · EPC C compliance · Stepping stone to Pathway 1 or 2
Key decisions that determine your pathway

What shapes your pathway?

Five factors determine which route is right for your organisation. The decision tool explores each one.

🏛️

Finance & balance sheet

Do you have capital or borrowing capacity, or does a partner need to bring the finance?

🏘️

Stock type

Houses, flats, or mixed? Flats need specialist metering and not all providers cover them.

👥

Resident outcomes

How much do residents benefit, and how comfortable are you with energy billing?

🔋

Batteries & revenue

Do you want to maximise revenue through grid services, or keep it simple?

📝

Appetite for complexity

Novel contracts and long-term structures create a different risk profile, but may be important for securing investment.

Answer a few questions to find your route

The tool asks simple questions first and guides you to a clear recommendation — with named providers and procurement routes.

💡 Best guesses are fine. Answer based on your current thinking — even if you're unsure. The tool will show you the best-fit pathway, but it won't rule out other options that might also work for your situation. You can always come back and try different answers.
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Provider profiles

An overview of organisations active in the social housing solar and battery market — what they offer and who they suit.

Important note: This is based on the Zero Carbon Accelerator market analysis (March 2025), project documents, and direct stakeholder conversations through early 2026. This is an emerging market with models which are evolving — offers, capabilities, and terms may have changed. Always verify directly with providers before procurement. A formal market engagement exercise is recommended before going to tender. Contact Energiesprong UK / Zero Carbon Accelerator for the most current picture.
Zero Carbon Accelerator · July 2026

About this tool

Background, acknowledgements, and how to get in touch.

Background

This decision tool was developed to help councils and registered providers in London (and beyond) navigate the rapidly evolving market for solar PV and battery storage on social housing. It draws on the Zero Carbon Accelerator Market Assessment for Financing Solar Power on Council Housing at Scale (March 2025), project documents from pilot programmes, and direct conversations with providers, councils and housing associations through early 2026.

The aim is to help landlords identify which financing and delivery pathway best fits their organisation — and to find the providers most likely to be relevant to their situation. This is an emerging market with models which are evolving; this tool is intended as a starting point, not a substitute for professional advice.

This tool has been developed with the assistance of AI. All content has been reviewed and verified by Energiesprong UK — and, for provider information, checked with the suppliers themselves or against published sources.

Acknowledgements

This work would not have been possible without the generous input, time and thinking of partner organisations and individuals — in particular:

  • The Mayor of London, through the Greater London Authority (GLA) — for funding and steering the Zero Carbon Accelerator programme
  • Rafe Bertram at Enfield Council — for detailed feedback and pilot insight
  • Camden Council, Hackney Council and Clarion Housing — for sharing their knowledge and the progress of their pilots
  • Mott MacDonald

Thank you also to all the providers, councils, lenders and advisers who shared their experience and helped sense-check the routes set out in this tool.

Disclaimer

This Report has been prepared solely for use by the party which commissioned it (the ‘Client’) in connection with the captioned project. It should not be used for any other purpose. No person other than the Client or any party who has expressly agreed terms of reliance with us (the ‘Recipient(s)’) may rely on the content, information or any views expressed in the Report. This Report is confidential and contains proprietary intellectual property and we accept no duty of care, responsibility or liability to any other recipient of this Report. No representation, warranty or undertaking, express or implied, is made and no responsibility or liability is accepted by us to any party other than the Client or any Recipient(s), as to the accuracy or completeness of the information contained in this Report. For the avoidance of doubt this Report does not in any way purport to include any legal, insurance or financial advice or opinion.

We disclaim all and any liability whether arising in tort, contract or otherwise which we might otherwise have to any party other than the Client or the Recipient(s), in respect of this Report, or any information contained in it. We accept no responsibility for any error or omission in the Report which is due to an error or omission in data, information or statements supplied to us by other parties including the Client (the ‘Data’). We have not independently verified the Data or otherwise examined it to determine the accuracy, completeness, sufficiency for any purpose or feasibility for any particular outcome including financial.

Forecasts presented in this document were prepared using the Data and the Report is dependent or based on the Data. Inevitably, some of the assumptions used to develop the forecasts will not be realised and unanticipated events and circumstances may occur. Consequently, we do not guarantee or warrant the conclusions contained in the Report as there are likely to be differences between the forecasts and the actual results and those differences may be material. While we consider that the information and opinions given in this Report are sound all parties must rely on their own skill and judgement when making use of it.

Information and opinions are current only as of the date of the Report and we accept no responsibility for updating such information or opinion. It should, therefore, not be assumed that any such information or opinion continues to be accurate subsequent to the date of the Report. Under no circumstances may this Report or any extract or summary thereof be used in connection with any public or private securities offering including any related memorandum or prospectus for any securities offering or stock exchange listing or announcement.

By acceptance of this Report you agree to be bound by this disclaimer. This disclaimer and any issues, disputes or claims arising out of or in connection with it (whether contractual or non-contractual in nature such as claims in tort, from breach of statute or regulation or otherwise) shall be governed by, and construed in accordance with, the laws of England and Wales to the exclusion of all conflict of laws principles and rules. All disputes or claims arising out of or relating to this disclaimer shall be subject to the exclusive jurisdiction of the English and Welsh courts to which the parties irrevocably submit.

Issue and Revision Record

Version history for the Solar Decision Tool. Update this table when issuing new revisions.

Revision Date Originator Checker Approver Description
1 July 2026 Energiesprong UK Energiesprong UK Mott Macdonald Initial release for submission — three pathways, nine provider profiles, and decision logic across building stock, finance, ownership, billing, batteries and complexity.
2 June 2026 Energiesprong UK Energiesprong UK Mott Macdonald Supplier information updated for Sero and Utilita following review of the completed supplier data-collection forms; National Wealth Fund removed (NWF is a finance source rather than a comparable operational model).
3 June 2026 Energiesprong UK Energiesprong UK Mott Macdonald Supplier-verified release. Provider information has now been reviewed and confirmed with suppliers: the Metis, Octopus, Sero and Utilita profiles reflect updated information from their completed supplier data-collection forms and direct responses. The Emergent, Allume/SolShare and Energy Local profiles are based on published information (principally the Zero Carbon Accelerator Market Assessment, March 2025).

Developed by & contact

Developed by Energiesprong UK on behalf of the Zero Carbon Accelerator (Mayor of London).

For further information, feedback, corrections, or to share your experience using the tool, please contact Energiesprong UK at info@energiesprong.uk.

Web: zerocarbonaccelerator.london