How much does an energy storage system cost?

Energy storage system costs stay above $300/kWh for a turnkey four-hour duration system. In 2022, rising raw material and component prices led to the first increase in energy storage system costs since BNEF started its ESS cost survey in 2017. Costs are expected to remain high in 2023 before dropping in 2024.

Why do we use units of $/kWh?

We use the units of $/kWh because that is the most common way that battery system costs have been expressed in published material to date. The $/kWh costs we report can be converted to $/kW costs simply by multiplying by the duration (e.g., a $300/kWh, 4-hour battery would have a power capacity cost of $1200/kW).

Are battery storage costs based on long-term planning models?

Battery storage costs have evolved rapidly over the past several years, necessitating an update to storage cost projections used in long-term planning models and other activities. This work documents the development of these projections, which are based on recent publications of storage costs.

How do you convert kWh costs to kW costs?

The $/kWh costs we report can be converted to $/kW costs simply by multiplying by the duration (e.g., a $300/kWh, 4-hour battery would have a power capacity cost of $1200/kW). To develop cost projections, storage costs were normalized to their 2022 value such that each projection started with a value of 1 in 2022.

What is a good round-trip efficiency for battery storage?

The round-trip efficiency is chosen to be 85%, which is well aligned with published values. Battery storage costs have evolved rapidly over the past several years, necessitating an update to storage cost projections used in long-term planning models and other activities.