There are several main approaches being developed for storing electric power using gravity. Let’s look briefly at each. The main advantage to all these kinetic gravity storage technologies is that you don’t need batteries. They also provide an alternative to problematic battery technologies. There are many problems with any battery modern technology including limited lifespan, limited capacity, and problems with production and disposal.
All current battery technologies rely on precious rare earth metals for production. They also contain toxic materials which usually end up in landfills. This creates international conflict and widespread human suffering both now and in the future, as toxins seep into groundwater and poison the land and the people.
In terms of sustainability, it is also a huge challenge to maintain batteries over time. When I visited Slab City in 2021, I found countless examples of discarded solar arrays sitting next to gasoline generators. The reason was always the same; it’s too expensive to replace expired batteries and keep using solar. These kinetic gravity storage technologies provide a workable alternative which frees communities from dependence on unsustainable battery technologies.
Pumped Storage Microhydro
One of the most common and widespread techniques for storing large amounts of power is pumped storage. Basically you have two lakes with a power dam in between. Then you use your extra grid power to pump the water from the bottom lake up to the top lake to store that power for later.
This can also work at a much smaller scale.
I wrote a whole post about pumped storage microhydro technology which I personally find most exciting of all these techniques because it can easily scale and be built cheaply or for free. All you need is two water tanks, some pipe to connect them, and a turbine/pump. You will also need some way of elevating one of the tanks, such as a hill.
The idea is basically you use your solar or wind to pump the water from the bottom tank up to the top tank. Then you slowly run the water back down through a turbine to the bottom tank to produce power. This works like a battery only with no toxic, dangerous, conflict-generating components. The side-effect is that it also gives you water pressure for your community.
One of the most popular new designs for kinetic gravity storage is using cranes. This means power is stored by stacking heavy blocks, and then released by unstacking them. These systems can store a great deal of energy over time.
Another common design in development uses abandoned mineshafts. By lifting and lowering a heavy weight, power can be stored or extracted for use.
Everything you would need to do these kinetic gravity storage projects can be found in any junk yard or hardware store. You can even build these components from raw materials. Every engineering student has to build motors from scratch, and you can too!