Floating solar at a quarry shows what UK rooftops could do

Nova has commissioned a 400kW floating solar array at a silica sand quarry in the UK, the first commercial installation of its kind in the country. The project, as reported by Solar Power Portal, sits on a former extraction lake and will power the quarry’s operations. But for the 15 million UK homes with a south-facing roof or a patch of garden, the question is: does floating solar translate to the domestic scale?

Why floating solar works, and where it falls short at home

Floating solar panels sit on pontoons anchored to the bed of a lake, reservoir, or slow-moving river. The water cools the panels, boosting efficiency by up to 10% compared to rooftop systems, according to the Energy Saving Trust. Nova’s quarry array will generate roughly 400,000 kWh a year, enough to power 130 typical homes. But a domestic version would need a body of water at least 20m², which rules out most suburban gardens. For households with a large pond or a flat roof that could be converted to a water basin, the technology exists. A 2kW floating system, about the size of a small garden shed, would cost around £4,000 installed, versus £3,000 for a ground-mounted equivalent. The extra cost comes from the pontoon structure and anchoring system.

What this means for your EPC and energy bill

If you have the space, floating solar can lift your EPC rating by one band, from D to C, by reducing purchased electricity. A 2kW system would save roughly £400 a year on a typical 3-bed semi’s electricity bill at current price cap levels (24.5p/kWh). But the payback period stretches to 10 years, compared to 7–8 years for rooftop solar, because of higher upfront costs. Ofgem does not currently offer a specific tariff for floating solar, though the Smart Export Guarantee (SEG) pays you for surplus power exported to the grid, typically 5–15p/kWh. The catch is that most SEG providers require a certified installer and a grid connection, which adds complexity for a water-based system.

Planning permission, the hidden barrier

Floating solar on a garden pond is likely to be considered a “development” under the Town and Country Planning Act 1990, meaning you will need planning permission from your local authority. The rules are different for flat roofs: if the panels sit within 10cm of the roof surface and do not project beyond the eaves, they are permitted development. But floating panels on a water feature are not covered by the permitted development rights that apply to ground-mounted solar. The Ministry of Housing, Communities and Local Government has not issued specific guidance on domestic floating arrays, so councils will judge each case on its impact on the landscape, ecology, and neighbours. That uncertainty alone may deter most homeowners.

The bigger picture, why this quarry project matters for policy

But the Nova project is not about homes. It is about industrial land, former quarries, reservoirs, and canals, that could host gigawatts of solar without taking up farmland. The UK has roughly 1,500 abandoned quarries, according to the British Geological Survey. If even a tenth were fitted with floating solar, they could generate 2GW, equivalent to a large gas power station. The government’s Solar Taskforce has called for 70GW of solar by 2035. Floating solar on water bodies could contribute 5–10GW of that, but only if the planning system treats it as a priority. For homeowners, the lesson is indirect: as costs fall through industrial deployment, small-scale floating systems may become cheaper. But for now, a standard rooftop array remains the most cost-effective way to cut your bills and your carbon footprint.

Households interested in floating solar should start by checking their local planning authority’s rules and getting quotes from MCS-certified installers. The Smart Export Guarantee payments are modest but can shave a few years off the payback. If you have a large garden pond and a south-facing bank, the technology works, but you will need patience, deep pockets, and a good relationship with your planning officer.