Capturing heat wasted in solar panels for use in distilling clean drinking water

Capturing heat wasted in solar panels for use in distilling clean drinking waterThe outlook of future PV farm: not just generating electricity, but also producing fresh water

…Testing of the modified solar panels showed them capable of purifying ordinary saltwater and seawater. In addition to removing dirt and other particles, the distillation process also removes dangerous heavy metals. Testing also showed the modified panels were able to purify up to three times as much as conventional solar stills. The researchers note also that the additions below the solar panels did not reduce their efficiency—they were still approximately 11 percent efficient.

Solar power with a free side of drinking water
Heat from a solar panel (upper surface) drives water vapor from seawater channels (dark blue) across porous membranes (orange) into freshwater receiver channels (light blue). Credit: Wenbin Wang 2019 

The researchers suggest their modified solar panels could be used in places where people have easy access to saltwater, such as the ocean, to provide clean drinking water. They further suggest that if future  included distillation capabilities, it is possible that they could produce up to 10 percent of the water consumed in the world. MORE

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Device could bring both solar power and clean water to millions

Hydrogen from seawater: Using solar power for electrolysis

 The breakthrough opens the door for widespread generation of hydrogen fuel powered by wind and solar energy.

Stanford University researchers have developed a method of generating hydrogen from seawater. The breakthrough harnesses solar power to drive the process of electrolysis to separate hydrogen and oxygen gas from water.

Previously, water splitting methods have relied on highly purified water, an expensive and precious resource.

Hydrogen fuel is a promising option in the fight against climate change because it doesn’t emit carbon dioxide when burned.

hydrogen from seawater such as this is being researched by Stanford University

Seawater could soon become a source of abundant hydrogen fuel after breakthrough research from Stanford scientists.

However, utilising the clean gas as a fuel to power cities and vehicles would be impossible, according to lead researcher, Hongjie Dai.

So the team turned to saltwater from San Francisco Bay. They created a proof-of-concept demo using solar panels, electrodes and ocean water.

A new way to harness hydrogen from saltwater

The Stanford prototype uses electrolysis: put simply, splitting water into hydrogen into oxygen using electricity. A power source (in this case solar panels) connects to two electrodes placed in water. Hydrogen gas bubbles from the negative end, oxygen from the positive.

Unfortunately, negatively charged chloride in seawater corrodes the positive end and shortens the life of the the The Stanford team found that by coating the anode with layers rich in negative charges, they repelled the chloride and halted the decay of the underlying metal. MORE