A New Renewable Energy Source that Could Support Half a Billion People

With ever increasing energy prices, and the knowledge that oil and natural gas will one day run out, scientists and engineers are constantly trying to discover new, renewable sources of energy. A recent article released in the Environmental Science and Technology journal describes a promising study by Ngai Yin Yip and Menachem Elimelech of the Department of Chemical and Environmental Engineering at Yale University.

Via a process known as pressure-retarded osmosis (PRO) they believe that enough electricity could be cleanly produced to support the needs of 520 million people. Their idea makes use of the difference in saltiness between freshwater river-water and salty seawater at the mouths of rivers around the world.

According to the American Chemical Society, “in PRO, freshwater flows naturally by osmosis through a special membrane to dilute seawater on the other side. The pressure from the flow spins a turbine generator and produces electricity.”

A similar study carried out by Stanford researchers last year came to the conclusion that PRO could generate 13% of the world’s energy needs.

Yip and Elimelech calculate that by using the water from just one-tenth of the rivers which flow into the ocean around the world should generate enough zero carbon electricity for more than half a billion people. In comparison, to provide the same amount of electricity from coal powered plants would release over one billion tonnes of greenhouse gases each year.

By. Charles Kennedy of Oilprice.com