Energy storage is how electricity is captured when it is produced so that it can be used later. It can also be stored prior to electricity generation, for example, using pumped hydro or a hydro reservoir.
With energy storage, we can capture electricity during times of low demand and return it to the grid during periods of greater need.
Convenient and economical energy storage can:
- Increase grid flexibility
- Simplify the integration of distributed generation and electric vehicles
- Improve power quality
- Limit periods of asset overload
- Keep the lights on when the power goes out
Energy storage methods
There are many ways to store energy.
For example, Canada’s extensive hydro reservoir system uses the natural landscape to store water until it is needed for electricity production.
Pumped hydro sites achieve the same availability benefits by pumping water into a reservoir when electricity demand is low and then draining it through generators to produce electricity when demand is high.
Other energy storage methods include:
- Flow batteries
- Solid state batteries
- Compressed air
- Pumped hydro
- Thermal storage
- Superconducting magnetic energy storage
- Electrochemical capacitors
- Hydrogen (including power-to-gas)
Economic challenge of energy storage
The challenge so far has been to store energy economically, but costs are coming down. A 2015 Deutsche Bank report predicted that “the cost of storage will decrease from about 14 cents per kilowatt hour today to about 2 cents per kilowatt hour within the next five years.”
Economical energy storage would have a major impact on the cost of electric vehicles, residential storage units like the Tesla Powerwall, and utility-scale battery storage applications.
Emerging energy storage technologies
Energy storage technologies are the key to modernizing the electricity system. Scientists and engineers are creating new technologies and modifying existing ones to meet our current and future needs.
CEA and its member companies are committed to staying at the forefront of this emerging issue.