Without electricity storage, we stand no chance of maintaining our economy using renewable energy. Unfortunately, we lack any scalable battery technology to meet this challenge. However, the problem might be that we are looking for answers in the wrong places. Rather than a single hi-tech solution, a dispersed combination of very low-tech approaches to energy storage may promise a more sustainable future.
According to David Z. Morris at Fortune, one low-tech approach to energy storage currently being tried in Nevada is an energy train:
“In April, the Nevada Bureau of Land Management granted environmental approval and a land lease to Advanced Rail Energy Storage (ARES), a startup with an energy storage solution that’s both novel and old-school. Apparently taking some inspiration from the myth of Sisyphus, ARES proposes to use excess off-peak energy to push a heavily-loaded train up a grade. Then, when the grid needs that energy back, the cars will be rolled back down the slope—but in a significant improvement on the myth, that return trip will generate energy and put it back on the grid.”
In practice, ARES is simply another way of using kinetic energy. In a sense it is the same as the many hydro-storage schemes that pump water uphill when there is surplus electricity, and then release it when demand spikes. The key questions will be, how much of the energy put in can be released again? – the company behind ARES claim 80 percent (although this is unlikely) – and how much will it cost?
Whether energy storage trains could be deployed in a population-dense country like Britain is a moot point. Certainly parts of Scotland, Wales and the North of England have steep enough hills to provide the kinetic energy. On the other hand, equally efficient kinetic energy schemes may be developed locally.