Seawater desalination is an excellent solution to the world’s lack of safe drinking water, but the problem is, desalination systems require huge amounts of power.
Water is at the core of sustainable development and critical for socio-economic development, energy and food production, healthy ecosystems and for human survival itself. There are around 2.1 billion people who lack access to safely managed drinking water, and water scarcity affects four out of every 10 people. These worrying statistics mainly concern those living in low-income and developing countries — particularly in coastal areas.
Many of these communities are off-grid and cannot afford to build, deploy and maintain grid-connected systems to desalinate — the act of removing salt from seawater.
Harnessing the power of ocean waves, Boston-based start-up Resolute Marine Energy has found a solution with Wave2OTM.
Wave2O can be deployed quickly, operates completely off-grid and supplies large quantities of clean fresh water at a low cost, all by making use of the abundant and consistent energy of ocean waves to drive the desalination process.
The group was selected as a finalist for MIT’s Solve Challenge: “How can coastal communities mitigate and adapt to climate change while developing and prospering?”
The Process
How it works is actually quite simple — a paddle on the ocean floor moves back and forth with waves, extracting energy. The system uses this energy to pressurize seawater that’s sent to shore to be desalinated. Because the system uses no electricity, it’s clean, modular and can be adapted for customers in lower-income countries with little to no infrastructure.
The plant, which has been under development for 10 years, includes several Wave Energy Converters (WECs) and 40-foot containers. One of these containers produces freshwater, and the others contain equipment that produces electricity (Wave2E TM), despite there being no electricity used in the manufacturing process.
The systems are readily scalable, which enables “just in time” adjustments to production capacity. This is because the entire Wave2O system is packaged in standard marine containers and can be installed in a matter of days. This allows water resource managers to more precisely match supply with demand without the need for massive infrastructure investments in pipelines, canals, and electrical production and transmission assets.
Diagram from Resolute Marine Energy
The system was tested in North Carolina and was set up on the beach in just two hours. For the launch, though, the company has a country like Cape Verde in mind.
Cape Verde, the Perfect Case
Cape Verde has a relatively small population spread across a nine-island archipelago. According to Resolute Marine Energy, although approximately 84 percent of its 530,000 inhabitants have access to a water distribution network, constant water shortages create stressful living conditions for the entire population.
Cape Verde’s renewable water availability is only 537 m3 per person per year, the second-lowest of any country in sub-Saharan Africa. Water scarcity makes Cape Verde reliant upon desalination to meet 85 percent of its needs.
“Cape Verde is an ideal place for us. It’s one of the driest countries in the world, has no river, no rain, limited aquifer, and because it’s an archipelago they have to import all the oils to drive the desalination system,” said the companies Chief Operating Officer, Oliver Ceberio.
“As a result, the cost of water in Cape Verde is one of the most expensive in the world. We believe that at commercial size, our plant could produce water at a third of the cost.”
Ceberio says that to meet their goal of implementing the system in Cape Verde by 2020-21, they need to raise around USD $9 million from investors in a Series A fundraising round.
He adds that the project will provide the need of water to 270,000 people and would offset carbon emission by an equivalent of 5,000 cars taken off the road.
The project already has support from organisations including the U.S. Department of Energy, the African Development Bank, the European Commission, the United Nations Industrial Development Organization, Ocean Wave Energy Trust and many more.