Researchers at Surrey Nanosystems have managed to create a material that absorbs 99.96% of visible light. The material is made of carbon nanotubes grown onto a metallic foil, and absorbs so much light that it appears to be a “hole” or “nothingness” when looked at.
While the researchers are still a long way off from commercial production, some discussion into the application of this material in the form of solar power has been brought up.
It seems pressing to point out that this material simply absorbs the visible light, and does not generate a voltage from it, so it seems ill-suited in its current form to be adapted to the photovoltaic market. However, the absorption rate of this material does make it a “game-changer” in the thermal-solar market.
Thermal solar doesn’t generate electricity, but it is used to heat water for homes. These are the larger, darker panels that are installed on roofs that are simply meant to get hot in the sun, and thereby heat the water in turn. This industry has been struggling to survive in the past few years as solar power became more widely affordable. Nearly 70% of the average household’s energy consumption involves heating and cooling, and that mostly includes the water heater.
Ten years ago, when solar power was incredibly expensive, many people turned to solar water heating as a compromise between reducing their electrical bill and the purchasing their hot water panels. But since then, solar power has been getting more and more commonly affordable, while water heaters at the same time have become more efficient. The result is the market for solar water heating completely evaporating.
So here’s where this new material comes in. By simply coating a single solar thermal module in this new material, the efficiency of these panels becomes much higher, enough to probably even boil the water. This material could change thermal solar from generating only hot water, to actually generating electricity.
There are roughly 1300 Watts of power for every square meter of sunlight on the earth’s surface. At 99.96% efficiency, the roof of a single-family household would be able to generate about 100kW of heat. That’s enough to power an industrial boiler. It would be interesting to see if this new material brings back steam-based technology.