Did you ever lie on a beach on a hot day when you were a kid, and dig your toes into the warm sand? Well if you did, then you were experiencing radiant solar energy first hand, and it felt so good. Sand batteries do something similar. They receive and store solar energy, and release it on demand. Someday we hope to see these sand batteries throughout the world. After all, the sand and the sun are already there.
Sand Batteries for the Developing World
Sand consists of small particles of minerals, that are common in that particular location. The tiny grains are the remains of rocks and stones broken down by wind and water, over countless millennia. They are most likely to be the remains of granite, quartz, or silica.
Large areas of the world have abundant sand and sunshine, but lack electricity in remote rural areas. The tiny communities there are far apart. This makes interconnecting them with an electricity supply grid, impractical. Those poor folk often lack the basic necessities we take for granted.
Perhaps installing maintenance free, scaleable, and inexpensive sand batteries throughout the world, could bring health and education to those who lack them? After all, sand is abundant and the sunlight is free!
How Practical is Storing Energy in Sand?
Perhaps it is best to provide an example. Finland is a Nordic country sandwiched between Russia and Sweden. This peace loving northern nation with a surprisingly moderate climate, experienced an energy crisis after it joined NATO, and Russia cut off its natural gas.
The residents in an isolated Finnish community reached out to their compatriots, who also had a vision of sand batteries throughout the world, and had started building them.
Barely a year later, the municipality of Pornainen has a sand battery full of silica, and capable of storing 100 megawatt hours of thermal energy from solar and wind sources. This gives them a green, reliable source of hot water to warm their homes, while their old wood chip boiler helps out during peak demand hours.
The sand battery heats the sand to a high temperature, by passing solar electricity through it. Cold water pipes pass through the super-heated sand, warming the water through thermal transfer.
More Information
Energy in Sand Beneath Our Feet
A Sand Battery to Keep Your Toes Warm
Preview Image: World’s Largest Sand Battery
