I kinda skimmed it. So from what I understand, they put a cooling layer behind regular solar panels. Panels get less efficient when they heat up so keeping them cool is where the extra efficiency comes from. The cooling layer is inspired by how plants cool themselves, it seems sort of similar to sweating in a way. Water moves through by capillary action, absorbs heat from the panel, and evaporates. Additionally they discuss:
using salt water as input water, which will result in some clean water output. It seems you need to kinda flush the cooling layer at night to get rid of salt crystal build up, but this could be a nice bonus in less developed areas.
use a condenser down the line to recover heat energy from the evaporated output water. Has the potential to raise total efficiency by a bunch of you can use the warm water for heating and the PV generated electricity for power.
They claim the cooling layer doesn't add much extra cost (6 months extra operation to recoup your investment). I wonder what the lifetime of the cooling layer is compared to the photovoltaics themselves. They use some natural fiber I think so maintenance could be an issue.
That was my immediate thought (maintenance), how does this compare to solar panel maintenance, which I'd assume consists of an occasional clean / check on the wiring?
It's not just a 10% increase in productivity, it produces fresh water as a byproduct:
Furthermore, the photovoltaic leaf is capable of synergistically utilising the recovered heat to co-generate additional thermal energy and freshwater simultaneously within the same component, significantly elevating the overall solar utilisation efficiency from 13.2% to over 74.5%, along with over 1.1 L/h/m2 of clean water.
It doesn’t make sense to think of it in terms of how much of the Sun’s energy it uses because solar energy is essentially free and unlimited, it comes from an outside system, we don’t need to mine it or carry it or anything and we can’t ‘waste’ it in the same way we can other fuels. All it tells us is the maximum theoretical limit.
10% more energy from solar means a rooftop array could generate an extra 300-500W which is a genuinely useful amount of energy.