5 strange ways to store energy

 By Jim McClelland

We are all becoming familiar with stories about advances in battery technology, from storage on the wall of your home, to wearables on your wrist, but what other weird and wonderful alternatives are available? This piece looks briefly at 5 of the more strange-sounding ways to store energy: in a football, in a cave, in a railway, in a salt, in a lemon. Yes, in a lemon…

(Cover photo by

It may be hard to believe, but energy storage is rapidly becoming big business, and surprisingly glamorous by association. Described as “set to explode,” the grid-connected energy storage market is forecast to see annual installations reaching in excess of 6GW in 2017, then accelerating up to over 40GW by 2022.
Energy storage is making headlines and even becoming associated with celebrity entrepreneurs. The glamour of the Elon Musk premium electric car brand Tesla has boosted the profile of its Powerwall home battery product in consumer media worldwide. In addition, storage is one of the primary investment and innovation priorities of the new Breakthrough Energy Coalition. Spearheaded by Bill Gates, the “billionaires coalition” boasts a who’s who of high-profile backers including Mark Zuckerberg of Facebook, Jeff Bezos of Amazon and Virgin’s Sir Richard Branson.

The football that generates electricity in developing countries...

Storage stories seem everywhere – from sleek units on the wall of your home to wearables on your wrist. However, a whole other world exists beyond interiors and fashion, where storage gets even more interesting.
As the spelling suggests, Soccket combines soccer with kinetic game-energy stored in an actual football. Invented by Harvard students and developed by Uncharted Play, the ball utilizes a gyroscope to harness and store sufficient energy in a battery to light a plug-in LED lamp for three hours, off just 30 minutes of play. Marketed for rural communities in Africa, Soccket provides a clean and green off-grid alternative to kerosene and diesel, which can carry significant air pollution and health impacts. It is an idea that has been kicked about by President Obama, literally.
On a different scale altogether comes energy storage in caves. On the Antrim coast in Northern Ireland, Gaelectric has won €6.5M ($7.3 million) in European Union funding to take the excess energy generated by solar and wind at peak times and convert it into compressed air to store in salt caverns almost a mile underground. The Compressed Air Energy Storage (CAES) at Larne will be able to provide 330MW of power for periods of up to 6 hours and help optimize the use of renewables.

The process of advanced rail energy storage 

Also involving salt, researchers at the University of South Australia have developed a low-cost phase-change energy storage solution which won the 2015 ANSTO Eureka Prize for Innovative Use of Technology. In this case, excess power from renewables is used to freeze salt and store energy for later melting and release. At a tenth of the cost of traditional battery storage, the molten-salt technology is now being developed for commercial applications in conjunction with Glaciem Cooling Technologies.
Another alternative storage route for surplus wind or solar energy from the grid effectively involves putting it on a train. The process of Advanced Rail Energy Storage (ARES) moves millions of pounds of mass uphill against gravity on railroad shuttles, storing thousands of megawatt-hours (MWh) of potential energy – enough to power a medium-sized city for several hours, on release. In other words: the train goes up, energy gets stored; the train comes down, energy gets recovered. Following a successful pilot in Tehachapi, California, ARES now has plans for a $55M 50MW facility in the Nevada desert.

Convert chemical energy from the acid in a lemon into electrical energy

Finally, having stored energy in a football, a cave, salt and a train, why not a lemon? An experiment conducted by educational specialists Steve Spangler Science demonstrates how to convert chemical energy from the acid in a lemon into electrical energy. Employing a little know-how around zinc-copper electrodes means this Fruit-Power Battery can then run an LED lamp.
So now, thanks to the strange world of energy storage, when life gives you lemons, as they say… you can make light!

READ MORE: Powering the energy storage revolution by Mike Scott


about the author
Jim McClelland
Editor + journalist for supplements to The Times + Sunday Times, also quoted in Guardian, Sunday Telegraph. I blog for such as GE + Gap. Active on social media. Specialisms include Sustainability.