Managing power demand peaks with virtual grid connection expansion

June 9, 2025

When the power requirements of a charging station grow, the limitations of the existing electrical connection often become apparent. Power is needed momentarily in large quantities, but most of the time, a large and expensive electrical connection remains underutilized.

The traditional solution would be to contact the Distribution System Operator, i.e., the grid company, and upgrade to a larger connection. However, this approach presents three significant challenges that affect both the timeline and profitability of electricity-demanding projects:

Availability. A larger electrical connection may not be available for the specific location.

Waiting time. Large-scale connection capacity changes often take months, even years. This delays the construction of charging stations or their full-scale utilization.

Rising costs. Electricity transmission capacity charges typically range from €3 to €5 per kilowatt. Increasing connection capacity by, for example, 600 kilowatts would raise monthly electricity transmission fees by a quite substantial amount.

An easier approach: virtual electrical connection upgrade

Instead of purchasing a larger connection from your distribution system operator, you can also expand your current connection virtually using a battery energy storage system (BESS).

By investing in a BESS from the project's early stages, you avoid unnecessary waiting with the grid company, get more out of your current connection, and pay less in peak-based demand charges.

A BESS complements electricity drawn directly from the grid. During consumption peaks, electricity stored in the BESS and grid power together enable momentarily higher capacity than the electrical connection's nominal size. When less electricity is needed, the BESS charges itself from the grid and is ready for the next consumption peak.

Such a system is particularly beneficial when:

  • Electricity consumption varies significantly
  • Consumption peaks are short-term, typically under an hour
  • Average consumption is clearly lower than peak power

How virtual connection capacity expansion works in practice

Here's an example of a typical situation where a Cactos battery energy storage system enables higher peak power with the current electrical connection:

  1. The charging station experiences a power peak that exceeds the grid connection's nominal capacity.
  2. The battery energy storage system begins supplying additional power with millisecond response time, complementing the maximum power available from the grid with exactly the required amount.
  3. When the consumption peak passes, the system automatically switches to recharging the battery energy storage during low consumption periods, utilizing more cost-effective time slots.
For example, with a 1-megawatt connection and 600-kilowatt battery energy storage system, a total power of 1.6 megawatts can be achieved without upgrading the grid connection.

Virtual electrical connection upgrade is based on intelligent energy management. For instance, Cactos systems are controlled by the Cactos Spine system, which continuously monitors both grid connection load and battery energy storage system charge status, optimizing energy flows in real-time. All of this happens completely automatically, without manual control requirements.

In this example, if all chargers at a station of three chargers are in use and dynamically share 300 kW of grid power, each vehicle would receive 100 kW. By adding 150 kW from a BESS, each vehicle would receive 150 kW.

Higher capacity, and much more

We have helped several companies requiring high-power charging to get more out of their current electrical connections.

Electric vehicle charging chain Faast overcomes connection capacity limitations with Cactos: when the electrical connection cannot provide more power, vehicles are also charged with electricity stored in the battery energy storage system. Additionally, the system participates in ancillary service markets, supporting the national power grid.

High-power charging providers benefit from peak shaving in electricity transmission costs as well. This has been noticed by, among others, service station Oulun Baari. When electricity consumption is more even, electricity transmission demand charges also remain moderate.

Taxi company Menevä shifts their exchange electricity consumption from expensive hours to cheaper ones. Timing taxi charging according to the most affordable price is difficult. When the battery energy storage system is charged during the cheapest time, cars can be charged without worry during more expensive hours as well.

Is your electrical connection blocking your project?

The launch of electric vehicle charging infrastructure or other electricity-intensive operations shouldn't fail due to connection capacity limitations. If expanding the electrical connection through the distribution system operator is too slow, expensive, or otherwise doesn't suit your business, peak power can also be increased with battery energy storage systems.

Cactos combines Finnish engineering expertise with practical problem-solving capabilities. All our products are developed in Finland and manufactured at our Kempele factory. This enables high quality, fast delivery, and reliable operation in all conditions.

The Cactos Spine system is designed to meet real-world challenges:

  • Intelligent energy management optimizes electricity transfer between grid, battery energy storage system, and application
  • The system always prioritizes local needs while also participating in supporting the national grid
  • Remote monitoring and automatic optimization ensure worry-free operation

Because we develop both our physical products and software in-house, we can respond agilely to our customers' needs and create functional solutions for new business models – with experience from over 150 installed battery energy storage system sites.

Interested in boosting your grid connection with a BESS?

We would be happy to help you assess the suitability and profitability of a BESS solution for your site. Contact us to discuss this with our experts.

Contact us

You can find more information about Cactos' solutions here.

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