The Emerald Lakes: large offshore storage basins for renewable energy

Maintaining the present world rate of economic rate progress over the next 50 years will require five times more energy than is available at present. Meanwhile, the use of fossil fuels, which at present supply about 80 per cent of needs, should be reduced to about 10 per cent. The shortfall could theoretically be made up by using just 20 per cent of wind potential and a small amount of solar photovoltaic (these sources could supply more than 50 000 TWh/year, compared with the present total of 15 000 TWh/year) But they are intermittent and would require a vast storage capability. Large offshore basins, based on proven technologies, could store 5000 x 109 m3 of sea water, the same as currently stored in hydro reservoirs. They could be used several times a week, according to the shortfall in wind or solar energy supply. Such valuable ‘green’ offshore structures, which could last for centuries, deserve the name ‘Emerald Lakes’.