Thermal energy storage (TES) systems generally have lower capital costs compared to many other long-duration energy storage technologies, including lithium-ion batteries, compressed air, and flow batteries, especially when considering discharge durations longer than eight hours.
Cost Comparison of Thermal Energy Storage to Other Energy Storage Types
| Technology | Approximate Installed Capital Cost (Capex, $/kWh) | Notes |
|---|---|---|
| Thermal Energy Storage | $232/kWh (global average) | Cheapest among LDES; significantly lower cost in China due to scale and policy support |
| Compressed Air Storage | $293/kWh | More expensive than TES globally; also benefits from large projects in China |
| Lithium-ion Batteries | $304/kWh (for 4-hour duration) | More expensive than TES for long-duration storage; better energy density for short duration |
| Flow Batteries | Higher than TES by about 66% | Early commercialization stages outside China, higher capital cost |
| Gravity Storage | $643/kWh | Highest among compared technologies |
Additional Cost Insights on Thermal Energy Storage
- TES systems are estimated at around 13.5 cents/kWh thermal energy for a 10% internal rate of return with approximately $350/kWh capex in some models, with potential cases below 5 to 10 cents/kWh thermal energy.
- Particle thermal energy storage using inexpensive and abundant materials like silica sand can achieve very low storage costs, estimated between $2 to $4 per kWh thermal energy at operating temperatures around 900°C, making it a promising, scalable, and safe option for large-scale long-duration storage.
Contextual Notes
- Although TES has lower capital costs, its energy density is lower than lithium-ion batteries, which makes batteries more suitable for applications requiring high energy density such as transportation.
- TES and other long-duration energy storage (LDES) technologies like compressed air and flow batteries have seen commercialization progress faster in China due to favorable policies and large-scale projects, leading to cost reductions there.
- Lithium-ion batteries remain cost-competitive for shorter-duration storage (around 4 hours) but become more expensive than TES and other LDES options for discharge durations beyond eight hours.
In summary, thermal energy storage systems are generally cheaper in terms of installed capital cost per kWh compared to lithium-ion batteries and several other long-duration storage technologies, particularly for long-duration energy storage applications. Technologies like particle thermal storage offer very low-cost and scalable solutions suited for grid-scale applications, though with lower energy density than batteries.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-cost-of-thermal-energy-storage-systems-compare-to-other-forms-of-energy-storage/
