Harrow Council commissioned Polysolar to roll out semi-transparent solar canopies to a group of vulnerable residents, following a successful pilot at a council home in the borough. The canopies turn unused garden space into a source of clean power and a sheltered outdoor room.

About the Project

Harrow Council's retrofit programme was part of a wider GLA-funded (HUG1 LAD3) initiative. It had already upgraded 38 council-owned dwellings with fabric-first energy efficiency measures. Many of these homes were unsuitable for conventional roof-mounted solar; roof condition, orientation, and residents' needs ruled it out for different properties.

Polysolar's answer was a solar glass pergola-canopy: a freestanding garden structure that generates electricity from its own roof, without any work needed on the house itself. Polysolar proved the approach first at a pilot home, then rolled the canopies out to further Harrow Council properties, chosen for residents whose mobility or health needs benefit from a sheltered outdoor space.

The Brief

• Deliver on-site renewable generation for homes where the roof was not a viable option for solar, without scaffolding or other invasive building work.
• Meet a minimum output target of 15,000 kWh across the properties, while keeping maintenance needs to virtually zero for residents who could not be expected to manage a technical system themselves.
• Align with EPC and PAS2035 retrofit standards, within a fixed programme budget.
• For several households, provide a genuine amenity benefit too, a covered, weatherproof outdoor space, rather than treat the canopy as generation infrastructure alone.

The Solution

Polysolar built each canopy as a freestanding, off-roof structure using PS-MC semi-transparent glass panels, sidestepping the constraints of the existing building entirely. The foundations use a screw-pile method instead of concrete pads, cutting both installation time and the structure's embodied carbon. Polysolar installed each canopy in around two days on site.

A 5kWh battery stores generated power for use after dark, and an online monitoring system lets Harrow Council track performance and flag faults remotely. Beyond the electricity it generates, each canopy doubles as a sheltered outdoor space. This was of particular value to residents with mobility needs, who benefit from a step-free breakout area right outside their door.

The Result

Polysolar designed and delivered six solar canopies under the programme, each built to the same 2.96 kWp specification proven at the pilot canopy. The whole programme was completed within three months.

Residents are expected to save around £256 a year each on their electricity bills.

"We are always open to new ideas that will help us in our plans for a carbon-neutral Harrow by 2030. This case study is the first of its kind, and we are proud to be part of this landmark project, which looks at making homes warmer, and as energy-efficient in a way never done before with social housing." — Cllr Mina Parmar, Cabinet Member for Housing, Harrow Council

The pilot canopy later featured at Grand Designs Live at London's ExCeL — the first use of transparent solar PV glass in a UK social housing retrofit.

Technical Specification

• System size 2.96 kWp per canopy
• Panel model PS-MC, semi-transparent, 370W
• Panel count 8 panels per canopy
• Light transparency 10%
• Inverter 3kW (Solis/Huawei)
• Battery storage 5kWh per property
• Foundations screw-pile anchors, no scaffolding or concrete pads required
• Warranty 10-year product warranty
• Canopies delivered 6, plus the initial pilot installation

Project Details

• Sector Residential / social housing retrofit, public sector
• Client London Borough of Harrow Council

Want a solar canopy for a site of your own? Get in touch to discuss your project: 01223 911534