The Future is 24/7 Solar
Dyson spheres are a long way off humanity’s theoretical capabilities, but the thermodynamic efficiency limit is one step closer thanks to researchers at the University of Houston. They’ve come up with a new technology that can be incorporated into solar panels, which can boost their performance to new levels.
The new type of solar energy harvesting system has broken the record of all existing technologies and works on the principle that existing solar systems reflect too much heat back to the sun rather than absorbing it.
Thanks to this new system, we are much closer to achieving the Landsberg limit of 93.3% efficiency, which is widely regarded as the absolute limit of solar energy harvesting, otherwise known as the thermodynamic efficiency limit. It’s hoped that this technology, when further improved, will allow for solar panels to be used 24/7.
Traditional solar cells inevitably bounce back radiation from the intermediate layer, which decreases the amount of energy gained from the sun. Some of this is absorbed by neighbouring cells, but the rest is lost. Researchers have now designed a layer that absorbs all the photons from the sun, converting them to thermal energy. The intermediate layer is thought to be able to only get to 85.4% efficiency, but thanks to this new technology, we should be able to reach the Landsberg limit in time.
The new nonreciprocal system is designed to make up for this deficit and is illustrated below. More energy is taken in by the nonreciprocal system as all of the photons are absorbed instead of being reflected.
These systems would be more compact and could be combined with thermal energy storage units to generate electricity 24/7. With some improvement, the nonreciprocal system can potentially reach the Landsberg limit.
Traditional solar panels rely on this intermediate layer to tailor sunlight for better efficiencies, which is what we’ve been relying on so far. However, by its nature, it doesn’t absorb as many photons as it has the potential to do. Traditional PV systems are designed in such a way that a neighbouring cell will capture the light that bounces off it.
It’s thought that this simple adaptation will offer a widespread rollout of highly efficient solar panels that can reshape the way we think of solar power. Factoring in the additional thermal energy storage units, and the potential to generate power 24/7, we could see a completely green electricity system in our lifetime.