Energy storage reduces carbon emissions primarily by optimizing when and how electricity is used, enabling better integration of renewable energy, and reducing reliance on fossil fuel-based power generation.
Key Mechanisms by Which Energy Storage Reduces Carbon Emissions
1. Shifting Energy Use to Low-Carbon Periods
Battery energy storage systems (BESS) can charge during periods of low carbon intensity on the grid—often when renewable energy output is high or overall demand is low, such as overnight—and then discharge during times of high carbon intensity or peak demand. This load shifting reduces the need to draw electricity from fossil fuel plants that typically provide power during peak periods. For example, charging a 1MW BESS overnight can save approximately 10,000 kg of CO2 emissions monthly compared to charging during the day when the grid is dirtier.
2. Enabling Greater Use of Renewable Energy
Renewable sources like wind and solar are intermittent and cannot be turned on at will. Energy storage allows excess renewable energy generated during sunny or windy periods to be stored and used later when generation is low or demand is high. This smoothing effect reduces the need for fossil-fuel backup plants, cutting overall emissions from the power sector. Studies of grids in California and Texas have found that incorporating storage can substantially reduce carbon dioxide emissions beyond just increasing renewable generation capacity.
3. Supporting Grid Stability and Reducing Fossil Fuel Plant Operation
Battery storage can provide ancillary services such as frequency response and dynamic containment, which traditionally require fossil fuel plants (like combined cycle gas turbines) to be running at partial load to maintain grid stability. By providing these services, batteries reduce the need for these plants to run inefficiently, reducing carbon emissions. In Great Britain, battery storage has contributed to over 1% reduction in power sector emissions since 2021, avoiding about 174,000 tonnes of CO2 by enabling the grid to operate with lower inertia and less reliance on fossil fuel generators.
4. Facilitating Smart Microgrids and On-Site Generation
When combined with on-site renewable generation (e.g., rooftop solar), energy storage allows sites to operate as smart microgrids that can reduce or even eliminate reliance on fossil-fuel-powered grid supply, further lowering carbon emissions.
5. Carbon Emission Reduction Depends on Charging Patterns
It is important to note that energy storage only reduces emissions if it charges during times of low marginal emissions—periods when the electricity supply is clean or excess renewables are available. Charging storage during high-carbon periods can diminish or negate emissions benefits.
In summary, energy storage reduces carbon emissions by storing electricity when the grid is clean and providing it when demand peaks or renewable generation dips, thus reducing the use of fossil fuel power plants and improving the efficiency of the overall power system. This enables higher penetration of renewables, decreases energy losses, and helps balance supply and demand in a way that lowers overall CO2 emissions from electricity generation.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-energy-storage-reduce-carbon-emissions/
