Composition and price of energy storage system

The cost categories used in the report extend across all energy storage technologies to allow ease of data comparison. Direct costs correspond to equipment capital and installation, while indirect costs include EPC fee and project development, which include permitting, preliminary engineering design, and the owner's engineer and financing costs.

The 2020 Cost and Performance Assessment provided installed costs for six energy storage technologies: lithium-ion (Li-ion) batteries, lead-acid batteries, vanadium redox flow batteries, pumped storage hydro, compressed-air energy storage, and hydrogen energy storage.

Cost metrics are approached from the viewpoint of the final downstream entity in the energy storage project, ultimately representing the final project cost. This framework helps eliminate current inconsistencies associated with specific cost categories (e.g., energy storage racks vs. energy storage modules).

Informing the viable application of electricity storage technologies, including batteries and pumped hydro storage, with the latest data and analysis on costs and performance. Energy storage technologies, store energy either as electricity or heat/cold, so it can be used at a later time.

Looking at 100 MW systems, at a 2-hour duration, gravity-based energy storage is estimated to be over $1,100/kWh but drops to approximately $200/kWh at 100 hours. Li-ion LFP offers the lowest installed cost ($/kWh) for battery systems across many of the power capacity and energy duration combinations.

The capital cost, excluding EPC management fee and project development costs for a 100 MW, 8-hour tower direct33 thermal storage system after stripping off cost for CSP plant mirrors and towers was estimated at $295/kWh, of which $164/kWh (or $1312/kW) corresponds to power block costs operating on a steam cycle (Lundy, 2020).