June 24, 2021

I, Science

The science magazine of Imperial College

The Sun has finally got his London hat on.  So to celebrate, here’s a warming story about smart scientists using solar energy to alleviate water poverty.

The Middle East is almost always sunny.  Jordan, for example, gets some of the highest levels of solar energy in the world – seven times as much as London on average.  While Brits might envy that most of the year, it causes serious water supply problems.

Five hundred cubic metres of fresh water per person per year is considered critically low.  Jordanians average just 148 cubic metres per person and climate change is set to make this worse.

Converting sea water – desalination – is a possible solution, and a process called reverse osmosis seems most promising.  But filtering salty water by forcing it through membranes uses large amounts of electricity.  Neither Jordan nor the climate can afford to burn more fossil fuels and areas most in need of fresh water are often too remote for power lines.

Instead, scientists from Qatar and Jordan have built a reverse osmosis plant that’s powered entirely by solar panels – or photovoltaic cells as they’re technically known.  Batteries store excess energy from Jordan’s searing sunlight during the day and keep the water flowing at night.

The plant, described in a paper to be published in Renewable Energy journal, has excelled in testing and now converts water from northern Jordan’s salty springs, supplying the area with up to 1300 litres of fresh water every day.