Sustainable clean water through solar-powered desalination for water-scarce islands and coastal regions (SDG: 2, 3, 6, 8, 11, 12, 14)

When one combines the endless supply of sea water found at the intersection of coast and sea, with the off-grid energy supply realized through use of solar cells and batteries/gravity, the opportunities for scaling up are endless. Combining this with the fact that global desalination rates reach 80 million m3/day, and have been growing by 10-20% annually, an opportunity arises in which the abundance of sea water and solar power can fulfill the existing and future needs of water scarce islands and coastal regions. Particularly urgent is the increasing pressure on fresh water resources on small island developing states (SIDS), which face increasing challenges of pollution, over-exploitation of surface, ground and coastal waters, saline intrusion, drought and water scarcity. This makes the need for Elemental Water Makers’ desalination solutions especially relevant and fit for region-wide adoption. By mitigating the fossil energy associated with reverse osmosis technologies used by conventional desalination systems, and by adopting energy recovery principles, Elemental Water Makers uses three times less energy to desalinate 1 m3 of water in comparison to conventional desalination installations. Continuous water supply without the need for batteries is facilitated by using a water buffer at elevation, which is filled by pumping up using solar energy and waste energy recovered from reverse osmosis. The use of renewable energy, independence from fossil energy, and high-regard for waste water treatment together foster high environmental sustainability while contributing to local social and economic sustainability, which become evident in the case of the Philippine Water Kiosk project. The Philippines Water Kiosk produces 11 m3/day of fresh water, leading to a 43% reduction in CO2 emissions (11 t/year), which are produced to an affordable rate (from 1.3$/m3) that is highly competitive to the tariff for the only alternative water source on which the people are currently dependent: lacking an alternative, the people currently pay 6$/m3 for fresh water of questionable quality in non-continuous supply, which is delivered by truck and forces people to spend the majority of their income on their basic need for water. This water-kiosk solution allows a 75% water cost savings that amounting to $300.000 and a pay back time within two and a half years. Cost-savings on household level greatly contribute to social and economic sustainability as they allow households to spend the money typically associated to high water costs on other basic human needs. Moreover, the fact that a continuous water supply is now guaranteed negates the need for households to spend unforeseen amounts of time and money to suffice their right to clean and affordable water through alternative sources. Further contributing to the social sustainability is the fact that Elemental Water Makers always guarantees operation and maintenance that can be met using local personnel, expertise and materials. This is fostered by partnering with local organizations in the effort to train local staff members, whom are taught to independently operate, maintain, distribute and sell water. Through their training, local personnel become economically empowered and their employment contributes to local economic and social development.