This article was first published in the April 2016 issue of WIRED magazine. Be the first to read WIRED's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online.

Joanna Slota-Newson wants to turn buildings into power plants – using transparent solar panels. The chief technology officer of Cambridge-based startup Polysolar is developing see-through panels that can be designed into buildings, greenhouses and canopies. "We're just trying to cover as much of the building as possible with photovoltaics," says Slota-Newson, 32.


Traditional solar panels have to point directly at the Sun. Polysolar’s panels, however, can be used on walls, rather than tilted-south facing surfaces, because, says Slota-Newson, they are "good at scavenging low level, non-directional ambient light”.

The first generation of 7mm-thick, 24kg panels were installed in the forecourts of two Sainsbury's petrol stations and a canopy at the Barbican Centre in London. Its latest installations include a transparent solar bus shelter in the centre of London’s Canary Wharf, which gives buildings in the area the option to adopt the panels. "It is made of our photovoltaic glass with photovoltaic powering interactive displays, signage and lighting and before going back into the grid," explains Slota-Newson.

Polysolar’s latest glass has thin film photovoltaic technology embedded in the centre of each panel. Costing £250 a square metre, the grey-tinted panel is capable of producing 12 to 15 per cent power conversion efficiency, a step up from the ten-person company’s earlier orange-tinted effort, which cost £175/square metre but only produced nine per cent efficiency. "It is transparent but it controls glare and it reduces thermal gain," says Slota-Newson. "This is a huge factor in terms of reducing energy use within the building."

Next up for Polysolar: removing the tint from solar panels. In 2014, researchers at Michigan State University created the transparent luminescent solar concentrator, which sits over windows and directs infrared light to photovoltaic solar cells at the edge of the concentrator. The panel is only capable of one per cent efficiency, however, making commercial roll-out unfeasible for now.


Polysolar's R&D group has created "perfectly clear" organic PV glazing at a "small scale", with full production expected to be in place in two years' time. “You can never generate a very large percentage of a building's power requirements from the roof alone,” says Slota-Newson. “We are making use of the rest of the building and really increasing the footprint available for photovoltaic.”

How it works

Thin-film photovoltaic cells (in orange) are deposited as a naturally translucent layer on to the glass (blue) before another glass sheet is laminated on top. Once embedded, they allow the panels to work at a much higher efficiency at varying angles than regular solar panels and can generate solar power at low levels of sunlight.