Behind-the-meter storage is a battery energy storage system (BESS) installed on the customer side of the utility meter, meaning it operates as part of a building or site’s internal electrical system rather than as a grid asset. In EV charging, behind-the-meter storage is used to manage site import limits, reduce costs, and improve reliability by supplying energy to chargers without increasing measured grid demand at peak times.
What Is Behind-the-Meter Storage?
“Behind the meter” means the battery is connected to the site’s electrical infrastructure after the utility meter, so it:
– Charges using the site’s grid supply (and/or on-site generation like solar PV)
– Discharges to serve on-site loads such as EV chargers, HVAC, lighting, or production equipment
– Helps control the site’s metered demand and energy costs
This differs from “front-of-the-meter” storage, which connects directly to the grid and is operated as a utility-scale or grid services asset.
Why Behind-the-Meter Storage Matters in EV Charging
EV charging can create large, short-duration peaks that exceed available import capacity or trigger high demand charges. Behind-the-meter storage helps site owners and CPOs:
– Add more chargers without immediate grid connection upgrades
– Reduce peak demand and avoid expensive demand charges
– Improve charger uptime by preventing overload trips
– Support battery load shifting under time-of-use tariffs
– Increase self-consumption of solar PV and reduce CO₂ footprint
– Enable limited backup power operation for critical charging when designed for it
It is especially useful for workplaces, fleet depots, retail sites, and public hubs where grid upgrades are slow or costly.
How Behind-the-Meter Storage Works
A behind-the-meter BESS is typically controlled by an Energy Management System (EMS):
– The EMS monitors building load, charger demand, tariffs, and site import limits
– The battery charges during low-demand or low-price periods, or when solar is available
– During peak EV charging demand, the battery discharges to supply part of the load
– The EMS caps the site’s grid import so the meter sees a lower peak
– Chargers may be coordinated through load management and power setpoints
Common operating modes include:
– Peak shaving (cap maximum demand)
– Load shifting (move energy use to cheaper times)
– Power boosting (short-term extra charging power)
– Renewable shifting (store PV generation for later charging)
– Load smoothing (reduce rapid demand swings)
Typical Use Cases
– Fleet depots charging many vehicles overnight within a limited import contract
– Commercial buildings adding workplace charging without upgrading the main connection
– Retail sites using batteries to reduce demand peaks during busy hours
– Public charging hubs where multiple sessions overlap and create high peaks
– Sites with solar PV aiming to maximize self-consumption and reduce energy bills
Key Benefits of Behind-the-Meter Storage
– Higher effective charging capacity without immediate utility upgrades
– Lower electricity bills by reducing peak demand and shifting load
– Faster site deployment and easier scalability
– Improved operational stability and fewer overload-related shutdowns
– Better renewable utilization and sustainability reporting
– Optional resilience capability when integrated with backup architecture
Limitations to Consider
– Requires accurate sizing and control strategy to deliver financial benefit
– Battery cycling causes degradation and must be included in the business case
– Added CAPEX, permitting, and safety requirements (fire protection, ventilation)
– Round-trip efficiency losses reduce net delivered energy
– Savings depend on local tariff structures and demand charge rules
– Not a substitute for grid upgrades if sustained high power is needed continuously
Related Glossary Terms
Battery Energy Storage System (BESS)
Battery Buffer Storage
Available Import Capacity
Energy Management System (EMS)
Peak Shaving
Battery Load Shifting
Power Boosting
Smart Charging
Microgrid
Backup Power Operation