Renewables can extend desalination viability

Desalination is energy-intensive, so using environmentally friendly energy sources is desirable – and can also be the most economic option. Demand for potable water in the Middle East is 203 billion m3 per year, and islands in the Caribbean and Oceania 80 billion m3, and these regions can be prime targets for green desalination with energy sources like solar and wave power, Lux researchers believe.

“Solar farms are the most appropriate for the Middle East due to the region’s abundance of land and sunlight, while emerging technology to harness power from sea waves is best for small island nations,” said Thomas Ooi, Lux research analyst and lead author of the report, Emerging green desalination: solar and wave technologies.

“Forward osmosis (FO), coupled with thermal solar, is another promising technology that can challenge incumbent photovoltaic solar and reverse osmosis (RO),” he noted.

Lux Research evaluated solar and wave power for desalination and six startups that offer state-of-the-art technologies. Among their findings:

• SunPower leads among solar firms for green desalination. SunPower’s solar panels require the least land – 0.8 km2 for a typical plant that produces 540 000 m3 of freshwater daily. In comparison, eSolar needs 2.4 km2 and Solar Euromed’s system takes up 3.6 km2. SunPower’s PV technology powering RO achieves a cost of $0.78/m3.
• Wavepiston leads in cost. Among wave energy startups, Wavepiston has the lowest levelised cost of water (LCOW) of $1.30/m3 while Resolute Marine Energy (RME) was second with $1.83/m3.
• Seatricity leads in commercial development. In terms of progress towards commercial development, Seatricity is far ahead of most wave energy developers, having weathered field trials in Scotland’s winter storms with waves as high as 15 meters.