usatoday24
Green hydrogen is the missing piece in the puzzle of decarbonization. In a day like today, in which Spain It has produced 107.3% of the country’s energy demand From renewable sources, a greater storage capacity (batteries or pumping centrals and a more flexible demand is needed. Produce green hydrogen When electricity is very cheap It is the country’s commitment to take advantage of that surplus.
There is a problem. While green hydrogen It occurs with solar or wind energy (That is why it is said that it is an energy vector that stores clean energy), the process to produce itwater electrolysis consumes huge amounts of fresh water, an increasingly scarce resource for billions of people in threatened regions For chronic drought.
The obvious solution is to use seawaterthe most abundant resource on the planet. But of course, salt and impurities run the equipment and reduce the efficiency of the process. External desalination makers are needed, adding costs and energy consumption; or super -resistant electrolyzers, which are still under development.
There is a third way. MIT researchers, Cornell University, Johns Hopkins University and Michigan State University joined forces to find an alternative that nicknamed the “triumph of sustainability.”
The system, detailed in Energy & Environmental Scienceproduces green hydrogen directly from sea water. It does so using solar energy with impressive efficiency, and generating drinking water as a byproduct.
How they have done it. Taking advantage of the entire solar spectrum. The central idea of this new approach, officially called HSD-We (Hybrid Solar Distillion-Water Electrolysis), is to squeeze the maximum solar energy.
We know that photovoltaic panels convert only part of sunlight into electricity (The most efficient are around 25% efficiency). The rest of the energy dissipates as a residual heat. What if that heat, instead of wasted, will be used for something useful? Eureka!
Simpler than it seems. Like many other systems for the production of green hydrogen, the HSD-We integrates solar panels that turn light into electricity and an electroly of protons exchange membrane (PEM) that breaks down the water molecules into hydrogen and oxygen.
The secret is at the rear of the solar panels, they are where the HSD-We has an interfacial thermal distiller coupled that uses the residual heat of photovoltaic cells to evaporate seawater. A simple membrane that absorbs salt water. It is a genius.
The best thing is that it works. The electricity of the solar panels directly feeds the electrolyz. At the same time, the residual heat of the panel heats sea water in the interfacial distiller, evaporating it. This pure water vapor (already without salt) is transported by a small air space to the electrolyz, where it is directly condensed in the anode, adding ultra -patrol water for electrolysis.
The prototype, tested by the MIT both in laboratory conditions, under simulated sunlight, and outdoors, on a partially sunny day, threw impressive figures. They achieved 35.9 liters of dry hydrogen per square meter of solar panel per hour, using real sea water. In terms of efficiency, The system turned 12.6%a comparable rate or even above current green hydrogen production technologies with drinking water.
Cheap hydrogen finally? Beyond technical feat, preliminary economic analysis is also promising. Not depending on external supplies of electricity or purified water, the operating cost is minimal, so the price of hydrogen produced with this system could drastically fall with the scale.
While conventional electrolysis fueled by the electricity grid and using drinking water It costs about 10 per kilothis HSD-We system, in exchange for a slightly larger initial investment, could reach 5 dollars per kilo after 3 years of operation and lower the kilo at 1 dollar in 15 years. A price that would undoubtedly change the rules of the game.
Image | Nickelgreen
In Xataka | Europe waste so much renewable energy that needs green hydrogen. And the country that leads it is Spain
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