Emissions from utility-scale batteries vary significantly by location due to differences in the local electricity grid mix, market design, and operational incentives. Key factors influencing these variations include the carbon intensity of electricity used to charge the batteries and how the batteries participate in electricity markets.
How Location Affects Emissions from Utility-Scale Batteries
- Grid Carbon Intensity and Charging Source
Batteries incur emissions primarily from the electricity used to charge them. If they charge from fossil fuel-heavy grids, the emissions are higher. Conversely, charging from renewable-rich grids lowers emissions. For example, in Texas (ERCOT), despite having extensive wind and solar capacity, most batteries increased emissions because they often charged during times of fossil fuel generation and lost 10-15% of energy in round-trip efficiency. - Market Design and Operational Incentives
Emissions outcomes depend heavily on market rules and price signals at specific locations. Batteries in energy-only markets like ERCOT chase revenue from ancillary services and energy arbitrage without emissions being a direct factor, leading to increased emissions in 92% of cases studied. This is because prices do not perfectly correlate with emissions—batteries charge when prices are low, but those times may still correspond to fossil fuel generation. - Locational Marginal Emissions (LME)
Emissions vary in real-time and by location based on the next power plant that would come online to meet demand. This means the emissions impact of charging and discharging batteries depends on the marginal fuel being displaced or added at that moment and place on the grid. Studies show that in many locations, battery operation increases locational marginal emissions because the next generation is frequently a fossil fuel plant.
Life-Cycle Emissions Considerations
- Beyond just operational emissions, batteries have embedded emissions from manufacturing and construction, which also vary by location depending on the carbon intensity of electricity used in production facilities.
- A life-cycle analysis comparing different utility-scale storage technologies shows batteries have higher emissions than pumped hydro due to energy-intensive manufacturing but do not emit fuel-related emissions during operation.
Summary Table of Key Location-Dependent Emission Factors
| Factor | Impact on Emissions | Location Dependence |
|---|---|---|
| Grid carbon intensity | Higher fossil fuel use increases battery emissions | Varies widely by grid region and time of use |
| Market structure and price signals | Incentives may favor charging at times of high fossil fuel use | Specific to electricity market design and regulations |
| Locational Marginal Emissions (LME) | Determines carbon impact of incremental demand changes | Changes minute-to-minute and location-to-location |
| Manufacturing emissions (embedded) | Carbon footprint from battery production | Depends on factory location and energy sources used |
Conclusion
The emissions from utility-scale batteries depend heavily on their geographic location due to variations in grid electricity carbon intensity, market incentives, and the marginal plants serving the grid at any given time. Batteries often do not reduce overall emissions unless they charge from low-carbon electricity and can displace more carbon-intensive generation, which requires aligned market mechanisms and grid conditions. Life-cycle emissions from production also vary by location based on local manufacturing energy sources.
Thus, utility-scale battery emissions are not uniform but highly location-specific, reflecting the complexity of grid dynamics and market factors in each region.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-the-emissions-from-utility-scale-batteries-vary-by-location/
