There is only one other gravity storage system that I know of that isn’t hydro, but it isn’t really a storage system. It is the Forterra ropeway used by a quarry in the UK where buckets of minerals are sent down a rope line similar to a ski lift. Since the quarry is uphill from the processing area, the energy from the material traveling along the rope is used to pull up all the empty buckets. Tom Scott did a YouTube video on it: https://www.youtube.com/watch?v=6RiYXI1Tfu4
I don’t know why they didn’t just put the mineral processing area closer to the quarry, maybe the quarry moved over time?
But anyway this is the only example of a viable gravity powered energy system that I know of that is not pumped hydro.
Here’s a dump truck at a mine that charges the battery via regenerative braking when hauling the material down the hill then uses that energy to drive the empty truck back to the top for the next load. Same idea.
Cool, I hadn’t thought of that. Thanks!
That’s pretty neat! But it seems to me it’s not storage because they’re not putting energy in to get out later. It’s more like mining naturally-occurring potential energy from the Earth’s crust. Probably that potential energy formed millions of years ago when tectonic plate activity pushed the rock up to its present elevation. So - it’s geothermal energy with extra steps.
Yep. As for why:
- the material being raised and lowered must be very cheap (to be able to afford much of it)
- the material must be possible to automatically handle in arbitrary amounts
- the friction of raising / lowering the material must be low
- the handling should not require a slope of particular grade or a specific height
Trains fail the cheapness and arbitrary amount check, along with the slope grade check. Sand fails the friction check. Concrete blocks are close to failing the cheapness and arbitrary amount check. Cranes fail the specific height check for certain ranges of height.
Water… it also requires a certain slope grade, but the range is not narrow.