All Commercially Available Long Duration Energy Storage Technologies, in One Chart
Long duration energy storage (LDES) technologies can store electricity for 10+ hours, complementing intermittent renewables, boosting grid resiliency, and reducing fossil fuel dependency.
Created in partnership with the National Public Utilities Council, this chart lists the characteristics of LDES technologies that have commercial or pre-commercial readiness, using data from the LDES Council’s Net-Zero Power report and 2023 deployment update.
The Four Primary Types of Long Duration Energy Storage
Before getting into the details, let’s cover the four primary types of LDES.
- Mechanical: Stores potential or kinetic energy
- Thermal: Stores energy as heat
- Chemical: Stores energy found within chemical bonds
- Electrochemical (batteries): Stores energy of chemical reactions, where electrical energy is converted to chemical energy and vice versa
Currently, mechanical storage systems are the most common around the world. Aboveground pumped hydropower, for instance, currently accounts for 96% of all utility-scale energy storage in the United States.
How Do LDES Technologies Measure Up?
Below, we list the storage capacity, storage duration, and average round-trip efficiency (RTE) of LDES technologies that have commercial or pre-commercial readiness on a global scale.
For context, RTE measures the effectiveness of a storage system by measuring the ratio of energy output to energy input during a full charge-discharge cycle. Or briefly, the higher the RTE, the lower the losses and therefore higher the efficiency.
The table above shows that a mechanical, gravity-based LDES system can provide the highest storage capacity while presenting an impressive 70–90% average RTE.
On the other hand, a chemical power-to-gas-to-power system, which typically converts electricity to hydrogen gas and back to electricity, provides the highest storage duration of up to 1,000 hours.
With that said, there are different storage needs and siting considerations across electrical grids. Given the diverse range of options available, a suitable solution can be identified to complement renewables and aid decarbonization.
Learn more about how electric utilities and the power sector can lead on the path toward decarbonization here.
