Overcoming the water challenge of green hydrogen production

Desalination station

In the western Sool region of Somaliland, the town of Ainabo/Caynabo has long been home to the Aynaba Well, one of the most famous wells in an arid country where wells are celebrated by poets. But severe drought has been putting heightened pressure on this storied water source, and in May 2021, the government of Somalia declared its drought situation a national emergency. The dependence of the Aynaba Well means that people’s source of drinking water is also the source for agricultural irrigation and local wildlife, and as a result it has become more brackish and less potable.

Enter Italian-headquartered company Genius Watter, a subsidiary of US-Canadian solar module manufacturer Silfab. Genius Watter’s “zero battery” solar water desalination solution won a United Nations Development Program (UNDP)tender last year for a minigrid and drinking water project in Caynabo set for commissioning this month. With the help of its partner, Uganda-based renewable energy company Aptech Africa, Genius Watter’s solution is a 41kWp minigrid and high-efficiency reverse osmosis plant capable of supplying 30,000L of desalinated drinking water each day from brackish wells.

The project needs to deliver fully automatic clean and affordable water to 15,000 people for at least 30 years, requiring only minor maintenance. Thanks to the plant’s 90% harvest rate on available PV net power the solution doesn’t require batteries. Genius Watter CEO Dario Traverso told pv magazine zero battery solutions were preferred because batteries remain expensive in this market and they also have a short lifespan compared to solar.

“Instead of storing energy we store water, either by gravity, as demonstrated in one of our projects in Kenya, in which we pump the water uphill when the sun is high, or in storage tanks,” Traverso said. “If unavoidable, small batteries for pumps can be used, but it’s far less expensive than incorporating a full energy storage system.”

The key to making these types of desalination solutions affordable is trying to get the least salty water possible. “It is much smarter to find ground-water than seawater, much less capex/opex and better ROI,” said Traverso. He noted that if you desalinate 100 liters of seawater, you’ll use more energy and end up with 40 liters of clean water and 60 liters of brine, while 100 liters of brackish water uses much less energy and returns 70 liters of clean water. In both circumstances, the brine can be dumped at sea without environmental damage, or used for applications like fish farming.

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Good timing and just the kind of projects needed.