in 2014 researchers verified that 95% of a pro system's theoretical power output can be produced with a membrane that is half (or less) the size needed for achieving 100%. output is proportional to the salinity. desalination yields very salty brine, while treated municipal wastewater has relatively little salt. combining those streams could produce energy to power both facilities. however, powering an existing wastewater treatment plant by mixing treated wastewater with seawater could require a membrane area of 2.5 million square meters.