Charging is growing faster than the grid
Europe is accelerating towards an electric future. Every day, more electric vehicles hit the road, businesses are electrifying their fleets and governments are investing in sustainable mobility. This presents tremendous opportunities for Charge Point Operators, fuel retailers, installers, and commercial businesses. However, it also introduces one of the biggest challenges facing the energy transition today: The electricity grid is struggling to keep pace.
Grid congestion is becoming a limiting factor for the rollout of EV charging infrastructure across Europe. New or upgraded grid connections can take months or even years to implement and increasing demand charges and infrastructure investment are putting pressure on project economics. The demand for charging is here today, but the available power is often not.
Different setups, same challenge
DC charging (30–300 kW+)
DC chargers are used for:
- public charging hubs
- petrol stations adding fast charging
- logistics and transport depots
- retail and hospitality locations
DC charging introduces high peak power demand, even when utilisation is intermittent.
AC charging (11–22 kW)
AC chargers are typically used at:
- office buildings
- commercial sites
- employee and visitor parking
- fleet locations with long parking times
These sites often start small but expand quickly as EV adoption increases.
Why Grid Limits Matter for Charging Hubs
When multiple vehicles charge at once, peak loads often exceed the capacity of the electricity connection. This results in:
- slower charging
- throttled power delivery
- inconsistent user experience
- potential penalties for demand peaks
Traditional grid upgrades are expensive, take months or years, and can be delayed by permitting and infrastructure bottlenecks.
Do I have enough power for EV charging?
To understand whether your site can support EV charging, you first need to know how much power is available on your electrical connection.
The basic formula
Current (Ampere) × Voltage (Volt) = Power (Watt)
A common large-user connection in Europe:
- 3 × 80 A
- Available power: ~55 kW
What does that mean in practice?
If there is no other electrical load on site, you have power for:
- 1 × 50 kW DC charger
or - 5 × 11 kW AC chargers
- You don’t have enough power for a 150 kW DC fast charger
In reality, buildings always consume power for lighting, HVAC, machinery, IT, and processes. This reduces the capacity available for charging even further.
Free Quick Scan
Typical Use Cases for Energy Storage Systems in EV Charging
1. Fast Charging Stations & Public Hubs
Large DC chargers demand high power in short bursts. Energy storage supplies these bursts from the battery and reduces reliance on peak grid power.
2. Workplace & Fleet Depots
Companies installing multiple AC or DC chargers can time-shift charging demand to reduce peak demand impact.
3. Logistics & Heavy-Duty Applications
Electric trucks and heavy vehicles require significant energy. A BESS helps supply this without overloading the grid.
4. Mixed Charging Sites
Combined AC + DC charging stations benefit from storage that supports both high and moderate charging simultaneously.
Typical business case with DC fast charging
Lets say a typical public charging hub operates 6 × 150 kW DC fast chargers, creating a theoretical maximum charging demand of 900 kW. However, the site has a 3 × 80 A grid connection, providing approximately 55 kW at 400 V three-phase. With this grid connection alone, the CPO cannot operate even a single 150 kW charger at full power.
To increase the available charging capacity, the site installs 3 Cellpower energy storage systems, each capable of delivering up to 125 kW. Together, the ESS units can provide up to 375 kW of additional power. Combined with the grid connection, this provides approximately 430 kW of maximum power available for EV charging.
Rather than limiting the site to a fixed number of chargers, the available power can be dynamically distributed across all six charging points according to actual vehicle demand. The EMS continuously allocates the available grid and battery power to the chargers that require it, maximizing the utilization of the available ~430 kW.
For example, if two vehicles require 150 kW each, they can receive their full requested power, while the remaining available capacity can be distributed among other vehicles. If several vehicles are charging simultaneously, the EMS can dynamically balance the available power between the charging points based on demand, charging priorities and configured operating strategies.
When overall charging demand is lower, the ESS units can recharge using the available grid capacity, preparing the system for the next peak. This enables the charging hub to serve more vehicles and provide higher charging power without requiring an immediate upgrade to the grid connection, while making maximum use of the limited grid capacity.
Typical business case with AC chargers
A company installs 15 AC chargers (11 kW each) for employees at its premises. The site has a 3 × 80 A grid connection, providing approximately 55 kW of total available power. During office hours, the building itself consumes around 20 kW for IT, lighting, ventilation, heating and the canteen. This leaves ~35 kW available for EV charging.
When 5 cars charge simultaneously, the load balancing system reduces charging power to about 7 kW per vehicle. When 15 cars charge at the same time, available power drops further to ~2.3 kW per vehicle. In this situation it will take 17 hours to charge a typical electrical vehicle from 20% to 80%. Charging is possible, but slow, unpredictable and highly dependent on building load. The number of chargers is not the limitation. The grid connection is.
What happens if this company adds a Cellpower energy storage system to the equation? With energy storage, charging performance becomes predictable and scalable, decoupling charging capacity from grid limitations. How does this work?
- Available kW increases to ~175 kW
- During office hours 175-20 = 155 kW is available for EV charging
- When 15 cars charge simultaneously the available power per car is 10 kW
- The cars can charge from 20 – 80% in less than 4 hours
Energy storage powering EV charging
An Energy Storage System (ESS) is a battery solution placed on-site to act as a power buffer:
- Charges when grid demand is low
- Discharges during peak charging times
- Reduces the need to draw high power from the grid
- Smooths peak demand and improves reliability
This buffered approach allows charging hubs to deliver high-power outputs consistently, even without grid expansion.
Adding power without upgrading the grid
An Energy Storage System (ESS) acts as a buffer between the grid and the chargers.
How it works:
- The battery charges when grid demand is low
- Stored energy is released during peak charging moments
- Chargers receive consistent power, even when the grid cannot supply it
This allows:
- fast charging on limited connections
- peak shaving
- predictable charging performance
- scalable expansion
From charging idea to viable business case
For many organisations, the key questions are:
- Do we have enough power for our charging plans?
- What happens during peak demand?
- How many chargers can we realistically support?
- Is energy storage more cost-effective than grid expansion?
- What if traffic increases by 50%?
Load profile analysis and scenario simulations make these questions measurable and investment decisions defensible.
Energy storage as part of modern EV infrastructure
EV charging hubs are no longer standalone assets.
They are part of a broader energy system.
Energy storage:
- stabilises power supply
- protects charging performance
- enables future growth
- reduces dependency on grid upgrades
Avoid downtime.
Choose the right BESS.
✓ Fast delivery from stock
✓ European quality and safety
✓ Technical support that makes the difference
We’re happy to help
Fill in the form or give our energy storage department a call: +31(0)88 – 514 99 02
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No larger grid connection and still expand
By applying peak shaving, companies with small grid connections still have enough power, even if they want to expand. This is especially useful when the grid operator cannot provide a larger connection. By smoothing out peaks in energy consumption, companies can make the most of their current connection and still grow. Want to know if this also applies to your business? We are happy to calculate it for you. Fill out the contact form and we’ll get to work for you.
CELLPOWER energy storage systems for peak shaving
The ultimate goal of peak shaving is to reduce peak load and ensure that sufficient energy is available at all times to power devices. This is exactly what a Cellpower peak shaving battery does for you, both on a small and large scale. From an advanced liquid-cooled system from 102 kWh to as much as 3,440 kWh. The systems are modular. So by adding additional systems, you can easily scale up energy storage when you want to expand further.
Each grid congestion situation is different. Sometimes installing an energy storage system is not the best solution at all, or you can do just fine with a smaller system. That’s why we like to make a calculation in advance based on your situation. Based on this, you can then make an informed decision.
How our customers solve grid congestion
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314 kWh – Postillion Hotel Bunnik
Postillion Hotel Bunnik makes sure they always have enough power with their very own Cellpower energy storage system
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261 kWh – TSSN
TSSN chooses Cellpower energy storage for peakshaving and increasing self-consumption of their sustainably generated power
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261 kWh – Dairy Farm Hoeve Boveneind
Dairy farm Hoeve Boveneind gets grip on it’s power consumption with Cellpower Energy Storage