Solar cell research continues to increase their efficiency and produce more free energy per square inch. However, the fact solar cells aren’t transparent means adding them to our power hungry gadgets is difficult. We can put them on the back of devices, but they are usually facing away from sunlight. Transparency would allow them to become part of displays as well as enabling every window to become an energy generator.
Researchers at UCLA are attempting to solve this problem by creating a new type of visibly transparent solar cell, and they’ve managed to develop one good enough for use on windows.
The new transparent cell works by harvesting solar energy from infrared rather than visible light. It does this by utilizing a silver nanowire-metal oxide composite conducting film that is almost transparent. The end result is a new polymer solar cell you can see through, but does have a slight impact on the visible light passing through it, much like sunglasses or tinted glass does.
As for how good this transparent cell is at harvesting solar energy, it is currently only managing a 4% efficiency, but that’s sure to be improved through further development.
A transparency limited to 66% and low efficiency will stop this cell being considered for integration with a touchscreen, but it certainly makes sense to add to a window or other non-interactive glass surfaces. The cell is also thought to be quite cheap to manufacture due to its use of a composite electrode made from a mixture of silver nanowire and titanium dioxide nanoparticles.
The transparent solar cell still has a way to go before being considered for commercialization, but I hope it isn’t too long before I can purchase some clear sheets to stick to my windows and start generating free energy.