From rooftops to residents – Hackney's 1 MW solar microgrid pilot

Jason Powell, Head of Operations, Hackney Light and Power, outlines the UK’s first ooftop solar scheme to use microgrid technology - helping to reduce energy bills for council flat residents.

Hackney’s Climate Action Plan commits the borough to net-zero by 2040. One practical step is to harness the opportunity presented by the roofs on its housing blocks. After a detailed review in 2021, the Council concluded that conventional landlord-supplied solar delivered too little value to tenants and offered no reliable route to repay the capital costs of installation. An independent market assessment pointed to a workable alternative, Emergent Energy’s private-wire microgrid model that provides income to repay the Council’s investment fully.

Turning an idea into an investment

An £80,000 grant from the Greater London Authority’s Local Energy Accelerator funded the initial business case and scoping. Hackney’s Cabinet then approved a £1.96 million budget in January 2024, drawing on the Council’s Carbon Offset Fund, a Hackney Green Investment opportunity issued through Abundance Investment, giving local residents a chance to back the scheme for a modest return, and some capital investment.
While Carbon Offset funds derisk the initial pilot, the project is a major breakthrough in providing a 100% commercial funding model for solar PV on blocks of flats at scale.

Delivery is set up in two parts:
A works contract to design, supply, and install around 2,000 solar panels and associated equipment across 28 blocks in Frampton Park, Whiston and Wren’s Park estates.

A concession agreement for a seven-year licence with an optional three-year extension, for Emergent Energy to operate the microgrids while the Council retains ownership of the assets.Energy-sector legal specialists Bevan Brittan assisted with drafting both contracts, ensuring compliance with procurement law and safeguarding customer interests.

How the microgrid works

Instead of only exporting power to the national grid and powering communal areas, each rooftop array feeds Emergent’s private network, which routes electricity into individual flats, too. Residents who opt in buy power at a discount while surplus energy tops up lifts, lighting and other communal services. Because income from sales flows back to the Council, the model generates a commercial return to repay the investment and direct savings for households.

Engineering the rooftops of the future

Detailed structural surveys confirmed load capacity and warranty requirements before installation partner Carbon3 began work. The one-megawatt portfolio should generate about 875 MWh a year, enough to meet up to 40 per cent of demand from participating households and avoid roughly 180 tonnes of carbon dioxide annually.

Skills, jobs and social value

From the outset, the Council formed a cross-departmental working group spanning housing, finance, legal, procurement and skills to develop the scheme and ensure it provided the best value for residents. Objectives go beyond carbon:

• The concession guarantees solar apprenticeships and accredited training.
• A Hackney Living Wage requirement keeps more project spend in the borough.
• Estate meetings, drop-in surgeries and co-designed literature ensure residents are kept updated from the outset and understand how the system works.

Why it matters

Hackney’s pilot shows that rooftop solar on blocks of flats can be financially viable, socially fair and technically robust. By combining council ownership, Emergent Energy’s pioneering business model, rigorous legal structuring from Bevan Brittan and community investment through Abundance, the scheme turns the split-incentive problem into shared value. The result is greener electricity, lower bills and local jobs delivered from unused space on Council-owned buildings.

As GB Energy develops and councils across the UK look for practical routes to clean, affordable power, the lessons from Hackney’s microgrid pilot are ready to be scaled far beyond the borough’s boundaries.

Jason presented at the APSE Energy London event in Westminster on Thursday 1 May 2025, his presentation can be viewed on the APSE website.