Scaling Green Hydrogen Means Finding Solutions To The Water Puzzle

While hydrogen from renewable sources currently represents less than 1% of all production, everything points to a boom in the coming decades. Since 2015, green hydrogen production costs have fallen by 40% and are expected to decrease at the same rate by 2025. Some studies even suggest that electrolyzers producing green hydrogen will be cost-competitive with fossil-based alternatives in a decade.

Meanwhile, innovators have been working to develop solutions to overcome another hydrogen hurdle: access to water. With green hydrogen requiring 10 to 15 liters of pure water per kilogram of hydrogen output, production in regions where solar energy would be readily available, such as deserts, are typically arid places.

In Australia and Singapore, two innovations offer a solution:

From thin air to hydrogen

Australian startup Aqua Aerem has developed a technique for converting solar energy into hydrogen by capturing moisture from the air and splitting it. If successful, the innovation could enable hot, arid areas around the world to become energy exporters.

• The system harnesses the sun’s energy through a concentrator photovoltaic system with dual-axis tracking that captures energy twice as efficiently as a standard silicon solar panel.
• In order to convert the energy into transportable hydrogen, Aerem has invented an atmospheric water capture system that sucks moisture out of the air which is then used for electrolysis.
• The company recently signed a testing deal with the government of the Northern Territory for a 12-week trial of the system. Going forward, Aqua Aerem plans on installing a 15-megawatt electrolyzer that will produce an estimated 912 tons of green hydrogen per year.

Water photovoltaics

U.S.-based startup Source Global has developed “hydropanels” which can convert humid air into water. Together with ENGIE Lab Singapore, the company has installed its innovative panels at the REIDS SPORE R&D platform in Semakau Island off the coast of Singapore, where the water will be used to produce completely green hydrogen to fuel a self-sufficient microgrid.

• Modeled on traditional photovoltaic panels, Source Global’s hydro version uses solar energy to absorb the water from moist air. A system of solar-powered fans direct the air into the hydropanel where it is purified and funneled into a tank — producing renewable drinking water.
• At the testing platform in Semakau Island, the water is injected into an electrolyzer and fuel-cell system which converts solar and wind power into hydrogen. This hydrogen can then be incorporated into a fuel cell to power an electric vehicle, or it can be reinjected into the local grid in the form of electricity.
• The multi-fluid microgrid, currently generating 550 kW of electricity and boasting Singapore’s largest wind turbine at 100kW, will be used by ENGIE Group and its collaborators, as well as educational and research institutes to test and develop additional solutions. ENGIE also intends to develop additional similar projects in partnership with the local ecosystem as a way of testing various new carbon-neutral technologies.