> The utility-scale PV-plus-battery technology represents a DC-coupled system (defined in the figure below), in which one-axis tracking PV and 4-hour lithium-ion battery storage share a single bidirectional inverter. The PV-plus-battery technology is represented as having a 130-MWDC PV array, a 50-MWAC battery (with 4-hour duration), and a shared 100-MWAC inverter. Therefore, the PV component has a DC-to-AC ratio (or inverter loading ratio [ILR]) of 1.3, which is the same as for utility-scale PV in the 2021 ATB. The assumed relative sizing is consistent with existing (but limited) data for online and proposed utility-scale PV-plus-battery systems—whose inverter characteristics (shared vs. separate) are not well known.
That very closely matches the ratio in the rollout they provide from the Berkley interconnection queue research. You don't just keep adding batteries, you add more renewable generation at the same time to maximize cost effectiveness.
This ratio is sometimes called "near firm" as it provides power when it is needed by the grid.
https://atb.nrel.gov/electricity/2021/utility-scale_pv-plus-...
> The utility-scale PV-plus-battery technology represents a DC-coupled system (defined in the figure below), in which one-axis tracking PV and 4-hour lithium-ion battery storage share a single bidirectional inverter. The PV-plus-battery technology is represented as having a 130-MWDC PV array, a 50-MWAC battery (with 4-hour duration), and a shared 100-MWAC inverter. Therefore, the PV component has a DC-to-AC ratio (or inverter loading ratio [ILR]) of 1.3, which is the same as for utility-scale PV in the 2021 ATB. The assumed relative sizing is consistent with existing (but limited) data for online and proposed utility-scale PV-plus-battery systems—whose inverter characteristics (shared vs. separate) are not well known.
That very closely matches the ratio in the rollout they provide from the Berkley interconnection queue research. You don't just keep adding batteries, you add more renewable generation at the same time to maximize cost effectiveness.
This ratio is sometimes called "near firm" as it provides power when it is needed by the grid.