A sorption-based atmospheric water harvester developed in Saudi Arabia could make photovoltaic devices more efficient in hot climates.
Commercial silicon photovoltaic panels transform a small portion of absorbed sunlight into electricity, while the remainder of the radiation becomes heat. Efforts to cool solar panels with techniques including refrigeration or air conditioning tend to consume more energy than can be gained back through efficiency boosts.
Now, a team led by Peng Wang from KAUST’s Water Desalination and Reuse Center has developed a proof-of-concept device that aims to reverse this situation via the natural properties of the Earth’s climate. The team’s results are published in Nature Sustainability.
The KAUST researchers have already developed a polymer containing calcium chloride, which is a powerful desiccant. When exposed to humid air, this material gradually expands as the calcium salts pull water into the gel, eventually doubling its initial weight. By incorporating heat-absorbing carbon nanotubes into the polymer framework, the team found they could reverse this cycle and trigger the release of water with solar energy.
