If renewable energy is to succeed, we need to find a better way to store it. Liquid air batteries could be the answer

Excess energy from the power station is used to power a giant fridge (Image: Jez Coulson/Highview)

Editorial: “Time to nail the number one problem of green energy“

IT HAS been an unusually cool day in the flatlands of western Texas. As evening rises over the sprawling wind farm, the temperature continues to drop, and with it the wind. Far above, the blade of a towering turbine glides slowly to a halt. A few hours ago, these turbines were churning sufficient electricity into the grid to rival two nuclear power plants, enough to keep the lights on in 5 per cent of Texas. The state’s power managers knew a drop was coming, but the speed has taken everyone by surprise.

The timing could not be worse. All across the state, people are coming home from work, flicking on lights, TVs and kettles. The power authority declares an emergency. Engineers request 30 megawatts of emergency power from Mexico. Supply to large industrial users is cut for more than an hour. It takes three hours before the system is finally stabilised.

This isn’t a good day for renewable energy and it illustrates one reason why even modest targets consistently go unmet all around the world. In 2009, intermittent renewables accounted for a paltry 3.3 per cent of world energy generation. Wind, sun and wave are simply too fickle to be counted on. But that may be about to change – and salvation could literally come out of thin air.

It’s not that we don’t have enough energy sources. Indeed, every minute, enough solar radiation hits Earth to meet global energy needs for a year. Wind could also single-handedly take care of the entire world’s demands, according …