Lewes Pergola: an innovative bespoke solution

Overview

This project began with a client in Lewes, East Sussex, who was eager to adopt solar but faced a significant design challenge. Their Georgian home featured a complex, multi-level roof with dormers and irregular shapes, which meant there was no suitable space for a neat and well-presented solar array.

The client was using around 8,000 kWh of electricity per year and wanted a meaningful reduction in grid reliance, so we explored alternative ways to introduce solar without compromising the appearance of their home.

The concept

During our initial consultation, the client showed us their garden, which featured a vegetable patch at the far end. By rethinking how solar could be used on the property, we proposed a completely bespoke solution: a large pergola designed to support a solar installation while enhancing the garden at the same time.

From there, we devised the idea of a solar pergola – an oak-framed structure standing three metres above the ground with a 10-degree roof pitch, built to carry bifacial solar panels. This gave the client the generating capacity they needed, while allowing the technology to blend into the garden rather than the house.

Planning and design

Because the structure sat within three metres of the boundary, planning permission was needed, which was granted without issue.

Ground screws were used to anchor the pergola posts, providing a strong foundation without the disruption of concrete footings. The main frame was built from green oak, with the solar panels mounted much like a flat roof installation but neatly integrated into the timber structure.

System Details

Inverter & battery storage: 10 kilowatt inverter with 10 KW of battery storage

Performance and technical specification

All wiring was run discreetly back to the garage, where a 10kW inverter and 10kW battery were installed. The system is expected to generate around 7,500 kWh of electricity each year, delivering an estimated 63% reduction in electricity bills. In winter, the client opted to top up the battery overnight using cheaper off-peak tariffs, leading to even greater annual savings.

Supporting plant growth

As the pergola is positioned over a vegetable patch, we gave careful consideration to light levels and shading. The bifacial panels allow UV to pass through and were spaced to maintain a comfortable amount of brightness beneath. In summer, the shade can help prevent crops from overheating, often improving growth and yield.

To support the growing area further, we incorporated a rainwater harvesting and irrigation system. A discreet gutter collects runoff from the underside of the panels and feeds it into a water butt, which supplies a drip irrigation line through the beds. This provides automated watering using collected rainwater, reducing maintenance while making the installation both energy-efficient and horticulturally helpful.

The solar pergola: A flexible concept with wide applications

The Lewes pergola shows how solar can be introduced where traditional roof mounting is impractical or would not look appropriate. This approach could be adapted for patios, paths, outdoor seating areas or other freestanding structures where space allows.

The initial update from our client was that plant growth under the pergola had been “super successful” and that during a spell of dry weather, the plant beds under the panels fared better than the rest of the garden as they didn’t dry out as much. The client’s garden was also opened to the public in an Eco Home Open Houses & Gardens event.

This project illustrates how creative thinking, thoughtful design and a flexible mindset can make solar possible even in places where a conventional installation simply would not work.