Do battery costs scale with energy capacity?

However, not all components of the battery system cost scale directly with the energy capacity (i.e., kWh) of the system (Feldman et al. 2021). For example, the inverter costs scale according to the power capacity (i.e., kW) of the system, and some cost components such as the developer costs can scale with both power and energy.

How are battery storage cost projections developed?

The projections are developed from an analysis of recent publications that include utility-scale storage costs. The suite of publications demonstrates wide variation in projected cost reductions for battery storage over time. We use the recent publications to create low, mid, and high cost projections.

When are battery cost projections updated?

In 2019, battery cost projections were updated based on publications that focused on utility-scale battery systems (Cole and Frazier 2019), with a 2020 update published a year later (Cole and Frazier 2020). This report updates those cost projections with data published in 2020 and early 2021.

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).

Why are Li-ion batteries becoming more popular?

In 2017, Li-ion accounted for nearly 90% of large-scale battery storage additions (IEA, 2018). The increasing share of Li-ion batteries in storage capacity additions has been largely driven by declining costs in Li-ion technology, which has in turn been driven by the ramp-up in production to meet growing demand for electric vehicles.