• Richard

Rocks in the Head? Can Trains really Supply Renewable Energy?

Undoubtedly, renewable energy is the future. There was a time for fossil fuels, but that time is at an end. Dirty, polluting remains of plants and animals long since departed must stay largely in the ground for our short-term health and for the long-term well-being of the planet. Ultimately, all sources of energy lead back to the sun - an essentially inexhaustible energy source that is yet to reach middle age. (NASA, 2018)

We are like tenant farmers chopping down the fence around our house for fuel when we should be using Natures inexhaustible sources of energy – sun, wind and tide. … I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that. - Thomas Edison, 1931 (Energy Matters, 2010)

There are clearly significant challenges around renewable power systems, however. These apply throughout the consumption chain: generation, distribution, storage and use. The good news is that solutions are getting better all the time. To take one storage related example, a 100MW storage array built by Tesla in South Australia has already saved the state from blackouts and is fortunately acting as a disruptor to established fossil fuel interests (ABC, 2017. Techspot, 2018).

One remarkable idea for storage that may yet gain traction -- pardon the pun -- is so simple and yet very clever indeed: harness the potential of kinetic energy with rock-filled trains (Live Science, 2014. Wired, 2016).

Train cars effectively become generators by using excess power to haul themselves uphill along with a heavy load - such as rocks. This will occur when the sun is shining, for example, or when the wind is blowing to excess in relation to demand. When the stored energy is required, the cars are allowed to run back downhill, converting movement (kinetic) energy into electricity. How brilliant. In such a relatively straightforward system (known as ARES), reliability is expected to be extremely high. Furthermore, the response-time to meet demand could be practically instantaneous. A facility is already planned for Nevada, USA.


On the generation side, the mix of sources is remarkably diverse. From geothermal to tidal, solar-concentrated, solar photovoltaic, wind and methane, there are many sources that together can comfortably satisfy future demand.

It’s beyond time for an Energy Revolution. Let’s go!


ABC, 2017 (Harmsen, N.) "South Australia's Tesla battery called on a day ahead of schedule as hot weather takes hold" [Accessed: 09.02.18] http://www.abc.net.au/news/2017-11-30/sa-tesla-battery-begins-producing-power-a-day-ahead-of-schedule/9212794

Energy Matters, 2010. "Thomas Edison - The Solar Power Visionary". [Accessed: 09.02.18] https://www.energymatters.com.au/renewable-news/em1144/

Live Science, 2014 (Parks, J). "Renewable Energy Rides the Rails to More Efficient Power Storage" [Accessed: 09.02.18] https://www.livescience.com/43211-renewable-energy-rides-the-rails-to-more-efficient-power-storage.html

NASA, 2018. "How Old is the Sun" [Accessed: 09.02.18] https://spaceplace.nasa.gov/sun-age/en/

Techspot, 2018 (Coberly, C.) "Tesla's massive 100MW South Australian battery is putting a big dent in 'gas cartel' profits" [Accessed: 09.02.18] https://www.techspot.com/news/73140-tesla-massive-100mw-south-australian-battery-putting-big.html

Wired, 2016 (Marshall, A.) "Forget Elon's Batteries - Fix the Grid with a Rock-Filled Train on a Hill" [Accessed: 09.02.18] https://www.wired.com/2016/05/forget-elons-batteries-fix-grid-rock-filled-train-hill/