The main sources of emissions during the operational phase of utility-scale batteries are primarily tied to the electricity losses incurred during their charge and discharge cycles, as well as the carbon intensity of the electricity used to charge them.
- Energy losses and round-trip efficiency: Lithium-ion batteries typically lose 10-15% of electricity between charging and discharging; for long-duration storage, losses can exceed 50%. These losses mean that more electricity must be generated to supply the battery than what is eventually delivered, effectively increasing the net load on the grid.
- Electricity generation emissions: If the electricity used to charge the battery comes from fossil fuel sources, the battery’s operation incurs a carbon footprint corresponding to these emissions. Since batteries consume energy with inherent losses, the carbon emissions depend heavily on the mix of generation sources charging the battery. Batteries must displace higher-emitting power plants to compensate for these losses in order to reduce net emissions, but in many grids, prices and emissions do not correlate strongly, so batteries do not inherently reduce emissions by following market signals alone.
- Grid-level operational dynamics: Battery revenue mostly comes from providing ancillary services (grid support functions) which are system-wide and not necessarily aligned with emissions reduction at a specific location. This disconnect can lead to increased usage patterns that do not prioritize minimizing carbon emissions.
Summarizing, the operational-phase emissions of utility-scale batteries mainly arise from:
- Round-trip energy losses requiring additional grid electricity generation.
- Carbon intensity of the electricity used for charging the batteries.
- Market and grid service incentives that do not necessarily align with emissions reduction goals.
These factors combined mean that many utility-scale battery systems today often increase overall emissions rather than reduce them during their operational phase unless deliberately managed to charge during low-carbon periods and discharge to displace fossil-generated electricity.
This nuanced understanding challenges the common perception that batteries automatically serve as carbon-neutral or emission-reducing devices in grid operation.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-are-the-main-sources-of-emissions-during-the-operational-phase-of-utility-scale-batteries/
