Solar powered Low cost seawater Desalination (SOLD)
|Coordinator||Stockholm Water Technology AB|
|Funding from Vinnova||SEK 300 000|
|Project duration||May 2018 - March 2019|
Purpose and goal
Solar powered Low cost seawater Desalination (SOLD) addressed the economic, social and environmental challenges that stem from water shortages, by validating a new low cost and low energy intensive water desalination technology called Capacitive Deionization (CDI), for converting sea water into drinking water. SOLD explored the advantages, limitations and nuances of CDI technology by studying the CAPEX and OPEX of the technology at system level, its energy requirements and water recovery parameters. New markets were identified and studied for implementation in the next phases.
Expected results and effects
SOLD results indicate that SWT-CDI technology is viable to be implemented as a clean and low energy alternative for converting Baltic Sea water into drinking water using renewable (Solar) energy. This opens up the possibility of grid independent and remote water desalination opportunities using a clean energy source. The high effectiveness of CDI to remove scaling metal ions like calcium and magnesium also makes it suitable for industrial and ground water applications. Widespread use of the low carbon footprint SWT technology will also indirectly promote the use of renewable energy.
Planned approach and implementation
A pilot unit comprising a single solar powered CDI module developed using the patented technology from SWT was installed near the sea at Torsby Sjöväg in Värmdo, Stockholm. Water was pumped into the SWT system reservoirs directly from the sea through a pre-filtration unit and directed into the CDI unit using a programmable control board. Water conductivity sensors, flow meters and energy meters installed at specific points enabled measurements of power consumption, water recovery and water quality, enabling monitoring and purification of sea water down to drinking water standards.