In the pursuit of green energy, storage is needed for 2 reasons:
- To smooth out the intermittency of solar and wind power.
- To store energy in electric vehicles.
Note: This page does not include thermal energy storage.
|Lithium-ion batteries||Needs too much cobalt|
|Lithium-sulfur batteries||Can't handle enough charge cycles|
|Sodium-ion batteries||Tech not ready yet|
|Sodium-sulfur batteries||Tech not ready yet|
|Lead-acid batteries||Toxic / hazardous|
|Iron redox flow batteries||Not suited for vehicles|
|Hydrogen gas||Energy losses, rare metal catalysts|
|Pumped hydro||Only viable in rare geographical locations|
|Gravity blocks||Outrageously high environmental footprint of construction|
For more details, read the wikipage of each energy storage type. Links are in the table.
So far, sodium-based batteries seem to have the most hope of being a widespread solution - along with iron-based batteries for stationary energy storage.
How much energy storage might be needed?
Some quick estimates:
^ This could be reduced by walkability and public transit (specifically trains).
We subtract transport because it was already dealt with above. We subtract industrial because - in principle, most factories/industry could just run during peak sunlight/wind, needing negligable energy storage.
^ This could be reduced by alternative heating/cooling systems for homes/buildings.
There are more options for this type of energy storage, because it's stationary (not moving in a vehicle).
These numbers might be reused on other wikipages to assess the large-scale viability of various types of energy storage. Don't worry if you're not familiar with
terajoules as an energy unit.