Electric Vehicle Charging Stations and BESS: More Power with a Limited Grid
The electrification of fleets, parking lots, and service areas is increasing the power requirements of many facilities. Simultaneous charging of multiple vehicles can generate high peaks and necessitate expanding the connection point. Integrating a BESS into a charging station allows for more flexible management of these needs and better utilization of the existing infrastructure.
The battery is charged when demand is low or when photovoltaic energy is available. When several chargers request power simultaneously, the BESS supplies a portion and limits the energy drawn from the grid. This function, sometimes known as power boosting, does not increase the contracted power, but it does allow for temporarily covering a demand exceeding the available capacity at the supply point.
Dynamic Charging Management
The EMS coordinates the grid, the battery, the chargers, and, where applicable, photovoltaic generation. It can also apply priority rules based on vehicle type, expected departure time, state of charge, or electricity tariff.
Dynamic management prevents the sum of the chargers’ power from exceeding the established limit. If the battery has sufficient charge, it provides the necessary power; if it reaches its limit, the system systematically reduces the charging power to protect the installation.
Main benefits
· Peak demand limitation: reduces the impact of simultaneous charging on the power supply.
· Possible postponement of expansions: can avoid or defer certain investments in service connection, transformation, or internal distribution.
· Greater photovoltaic integration: surplus solar energy can be stored and later used to power vehicles.
· Cost optimization: the battery can charge during off-peak periods and support charging during peak hours.
· Deployment in locations with limited power: facilitates the installation of fast charging where the grid cannot continuously deliver the required power.
· Improved user experience: allows for more charging sessions or maintains higher power levels during periods of high demand.
Power, Energy, and Simultaneity
Sizing must be based on mobility data: number of vehicles, power of each charger, simultaneous charging, session duration, and available time to recharge the BESS. A battery with high energy but low power will not provide sufficient power for a fast charge; a very powerful but small battery will only provide backup power for a short period.
Cycle efficiency, degradation, temperatures, and projected fleet growth must also be considered. In facilities open to the public, the availability and charging strategy of the BESS itself are especially important to prevent it from running out of power before a peak demand.
An Integrated Energy Infrastructure
The combination of charging, photovoltaics, and storage transforms the parking lot or station into a manageable energy system. Furthermore, the BESS can provide other services when not supporting the chargers, such as reducing overall building peak loads or increasing self-consumption.
At Vector Energy, we design BESS solutions coordinated with the charging infrastructure and electrical limits of each site. The result is a more flexible, scalable facility, ready to support the growth of electric mobility.
More information: sunvec.es/storage