Could there already be an alternative to the Lithium-Ion battery?
Zinc-based batteries
This includes longer durations as storage, as well as the fact that the aqueous-based systems are non-flammable.
The systems experience very low degradation and can last for 20-plus years — in line with the life cycle of a lot of renewable energy plants, which is typically 20 to 30 years. The technology is flexible in sizing, and zinc is abundant as a raw material. The technology stores energy using zinc deposition. Zinc-based batteries consist of a graphite felt and conductive plastic inside, and the zinc essentially adheres to and then releases itself from the graphite and conductive plastic to charge or discharge.
Iron-air batteries
Form Energy’s iron-air battery systems comprise modules that are roughly the size of a washer and dryer set, with cells that include iron and air electrodes. One of the technology’s benefits is that it is built with active components that are safe, cheap and easily found.There’s also the multi-day duration it provides — roughly 100 hours, which means it can be a great grid reliability resourceThe battery uses a process called “reversible rusting.” It converts iron metal to rust to discharge, and uses an electrical current to convert the rust back to iron to charge.
On paper, Iron-air batteries are much cheaper, and last much longer as well in comparison to lithium-ion.
Hydrogen energy storage
Hydrogen-based energy storage allows the power sector to use renewable energy and electrolyzer systems to create green hydrogen, which can then be stored for as long as needed until being converted back to electricity using fuel cells.
The Pacific Gas & Electric microgrid has a 48-hour duration, with the potential to expand up to 96 hours – but hydrogen allows for the possibility to store energy for much longer periods, even seasonally. This is particularly helpful for regions which experience power shut offs due to weather conditions or other circumstances.
Gravity-based storage
Using gravity as a form of energy storage has been around for a while, in the form of pumped hydropower — but using mobile masses is a relatively new concept, which Energy Vault has also been working on.
The technology essentially uses a mechanical process of lifting and lowering composite blocks made from soil and waste materials to store and dispatch energy, and Energy Vault says that it isn’t dependent on a specific topography, offers a flexible duration that can go from four to 24 hours, and has a 35-year lifespan.
It’s a low environmental footprint, there’s no supply chain issues, and it can scale — you can do it at really small scale, or really large scale.
As with all of these solutions, the main problems tend to lie within the infrastructure, investment & upscaling. Whilst all are promising for the near future, without proper infrastructure it is difficult to pinpoint exactly which of these is the most viable alternative.