Page 40 - AW MayJune 19

TECHNO NEWS

Delivering cheap and clean water with

just solar power

aking ocean water potable is usually an expensive to the grid or using a set of expensive batteries to store
Mand polluting prospect but in a coastal city in power.
Namibia, a Finnish startup company has found a way to In some remote communities, especially ones on
do it with clean energy. small islands, the systems could replace pricey, polluting
The company found a new technology that uses diesel-powered desalination. Because it can eliminate the
solar power to turn ocean water from the Atlantic into operating cost of diesel fuel, the technology can pay for
drinking water. Namibia is in the middle of a prolonged itself within three to four years.
drought. A second state of emergency in three years was The technology is also useful far from the coast; in
declared because the lack of rain is leading to severe Kenya, the company has installed systems in rural villages
food shortages. where groundwater used for drinking is too salty for healthy
But if scaled up, this technology through a simple consumption. The process also filters water through a
desalination device could help supply households and membrane that removes bacteria, viruses, and other
agriculture with fresh water. The basic tech that it uses for contaminants. The devices are modular, and a smaller
desalination, called reverse osmosis, isn’t new but because system can produce 3,500 liters of water an hour.
the system can run on solar power, without the use of The first system is already in place on the campus of
batteries, it avoids the large carbon footprint of a typical the University of Namibia, and the water will be used in
energy-hungry desalination plant. It’s also significantly part to irrigate a new “carbon garden” of trees planted
cheaper over the lifetime of the system. to help remove CO2 from the atmosphere. But similar
Desalination usually uses large amounts of electricity systems could help address the country’s water challenges
because reverse osmosis requires keeping water at a at a larger scale, and could help the country prepare for
constant pressure. The new tech keeps water at the right a future that’s likely to involve more drought as climate
pressure independently, so it can work without connecting change worsens. AW

38 MAY/JUNE 2019 Asian Water