OPINION
Solar windows are the very latest in eco-technology. Environmental journalist Robin Whitlock explains all you need to know and why they could be worth waiting for
As the latest in a run of cutting-edge renewable energy products, solar windows could, eventually, be the ideal option for those who love the idea of solar panels but don’t enjoy their look on top of the roof. Their availability in the UK makes them a little way off mainstream use, but if you’re planning to upgrade your home with eco-conscious solar generation, this is a technology to keep your eye on.
WHAT ARE SOLAR WINDOWS?
Solar windows look very much like ordinary glass windows except they also generate solar power from UV and infrared light. They are made of special solar glass that looks like conventional tinted glass — totally clear solar glass isn’t currently available as yet.
The big advantage of solar windows is that they enable a range of buildings, particularly homes and offices, to generate solar power. However, solar glass has only been installed into a select number of projects thus far, most of which are for commercial use, rather than domestic.
HOW DO SOLAR WINDOWS WORK?
Solar glass works very much like solar panels but has the added advantage of allowing light to pass through it into the space beyond. It consists of solar PV (photovoltaic) glazing that contains solar cells and which, like the silicon wafers on conventional solar panels, generates electricity from sunlight. Like solar roof tiles and roof-integrated panels, they are a form of Building Integrated Photovoltaics (BIPV), which is built into the property rather than installed on it.
There are various forms of solar glass:
● APV ink or film can be sprayed onto the glass surface either during the manufacturing process or on to existing windows. A company called NEXT Energy Technologies also produces a transparent PV ink that can be printed directly onto windows, while Solar Window Technologies
produces flexible glass with a PV coating that can be installed on existing office windows.
● Small PV ‘micro panels’ can be placed in the sides or corners of windows so that light can still pass through the glass.
● Double-pane solar windows have solar cells installed between two panes of glass. This also helps to provide insulation so the windows can reduce heating and cooling costs while also generating solar electricity.
● Quantum dots, which are still under development, are nano PV cells implanted directly into the glass. When installed, the power generated by the solar glass is connected to the bui
