Perhaps the one place we would never have thought to place solar panels is the windows in our houses. But silicon solar cells are not the only way to turn sunlight into electricity.
We have written in the past about organic solar modules; organic photovoltaics (OPV) are light and flexible and can therefore be installed in places a traditional panel would never fit. But OPV are not the only alternative to silicon.
At various cutting-edge research centres they are perfecting a completely new technology: luminescent solar concentrators (LSCs).
The challenge is to create surfaces that can produce energy from sunlight but remain transparent.
So, special luminescent dyes have been invented that can capture photons from the sun and re-emit them in a different wavelength (and therefore a different colour). These dyes are placed inside glass panes or, what is better, inside highly transparent plastics like polycarbonate or plexiglass, used for spectacles and visors on motorbike helmets.
This creates transparent panes of glass in different colours, which can absorb sunlight at a certain wavelength and relative colour. The trick is that the light re-emitted by these dyes is mostly trapped in the pane and channelled to its slender edges.
It is the same principle by which fibre-optic waves are guided, but in their case, the direction of the signal is linear. With these panes, on the other hand, the energy of sunlight is channelled to the two parts of the LSC pane.