How does using a storage system affect my carbon footprint?

Using an energy storage system reduces your carbon footprint by storing excess renewable energy (e.g., solar or wind) and discharging it when grid power is dirtier. For UK users, this means fewer fossil fuels burned to meet your demand, especially during peak hours or when renewables are scarce.

Types of storage systems

DC-coupled systems (like solar-battery hybrids) are more efficient, losing less energy during storage and discharge. AC-coupled systems (often retrofitted to existing solar setups) are easier to install but lose more energy through conversions.

Key impacts on carbon emissions

• Reduced grid reliance: A typical UK home battery charged by solar can offset 500–800 kg of CO₂ annually by avoiding peak-time grid usage (often gas-powered).
• Frequency services: Large-scale UK batteries provide grid-balancing services like Dynamic Containment, which prevents fossil fuel plants from increasing output during minor grid disruptions. Since 2021, this has cut GB’s power sector emissions by over 1%.
• Optimised renewable use: Storage ensures surplus solar/wind energy isn’t wasted, addressing the UK’s intermittency issues (e.g., low wind periods in 2023).

UK-specific considerations

• Policy drivers: The UK aims for 970 GW of grid-scale storage by 2030 to support net zero. Homeowners can benefit via Smart Export Guarantee payments for excess stored energy.
• Carbon intensity: In 2023, GB’s grid achieved a record-low carbon intensity of 33 gCO₂/kWh during optimal periods. Storage helps you target these low-carbon windows for high-energy tasks.

Practical advice

Pros

• Immediate savings: Reduce reliance on gas-fired power, which still supplies ~40% of UK electricity.
• Future-proofing: Aligns with rising carbon taxes on high-emission businesses.

Common mistakes

• Oversizing batteries: Adds unnecessary embedded carbon from manufacturing (e.g., lithium-ion).
• Ignoring software: Basic systems discharge randomly; smart ones sync with real-time carbon intensity data (e.g., National Grid ESO’s Carbon Intensity API).

Recommendations

• For new solar installations: Choose DC-coupled systems for maximum efficiency.
• For existing setups: Use AC-coupled batteries like Tesla Powerwall, but prioritise software that avoids charging during high-carbon periods.
• Businesses: Explore hybrid systems with controlled discharge during peak pricing/high-carbon hours.

Future outlook

The UK’s expanding carbon capture infrastructure (targeting 30 million tonnes/year by 2030) will further lower grid emissions, but storage remains critical to handle renewables’ variability. Small-scale storage users contribute indirectly by reducing strain on large-scale CCS projects.