Short definition: A flexible connection (also known as an interruptible connection or CPA connection—Connecting Parties Agreement) is a grid connection under which the grid operator has the contractual right to temporarily reduce the available connection capacity in the event of grid overload. In exchange, the connection becomes available more quickly than a standard fixed connection. With a battery as a buffer, this risk is fully manageable.

How does a flexible connection differ from a fixed connection?

Feature Fixed connection Flexible connection
Guaranteed connected load Always fully available Maximum value, but temporarily reducible
Waiting time during congestion Long (3–7 years) Shorter (6 months – 2 years)
Connection fee Default Sometimes a lower reimbursement as compensation
Operational risk None (warranty) Yes — but manageable on battery power
Suitable for critical processes without a backup Yes No
Suitable for critical processes with battery backup Yes Yes

How often is a flexible connection actually restricted?

The frequency of restrictions varies by region and season. Based on data from Dutch grid operators:

Traffic congestion intensity in the region Estimated annual restriction events Average duration per disability
Light traffic 5–20 times a year 1–3 hours
Moderate congestion 20–60 times a year 2–6 hours
Heavy traffic 60–150 times a year 2–8 hours

In the worst-case scenario, there could be up to 150 load-shedding events per year, each lasting an average of 6 hours. That amounts to 900 hours per year during which connected power capacity may be reduced—less than 10% of the total annual hours.

How large does the battery need to be to serve as a backup for a flexible connection?

The required battery capacity depends on:

  • The maximum power reduction that the grid operator can impose (kW)
  • The maximum duration of a restriction (hours)
  • The critical power consumption of your business processes (kW)

Formula: Battery capacity (kWh) = Min(power reduction, critical consumption) × maximum restriction duration (hours)

Example: The grid operator can reduce your connected load by 300 kW for up to 4 hours. Your critical processes consume 200 kW. The minimum battery capacity for full continuity is 200 × 4 = 800 kWh. In practice, 400–600 kWh is often sufficient if you can temporarily pause non-critical processes.

The business case for a flexible connection + battery

A flexible connection combined with a battery offers two mutually reinforcing advantages:

  1. Faster time to market: instead of waiting five years for a fixed connection, you can be up and running within one to two years. The revenue you generate sooner as a result has enormous economic value.
  2. Battery benefits from day one: the battery you install as a backup for your flexible connection also handles peak shaving, self-consumption, and, if necessary, congestion management. You’re investing in a multifunctional system, not just an expensive backup.

Frequently Asked Questions About the Flexible Connection

What exactly is a flexible connection?

A flexible or interruptible connection is a grid connection that allows the grid operator to temporarily reduce the available power in the event of an overload. In exchange, you’ll be connected more quickly than with a standard fixed connection, which involves a waiting period.

What are the terms and conditions of a flexible connection?

The exact terms and conditions vary by grid operator and project, but typically include: maximum power reduction (kW), maximum duration per restriction (hours), maximum annual restriction hours, advance notice period (hours/minutes), and any compensation payments.

Can I switch from a flexible plan to a fixed-line connection?

In most cases, yes, but that means you’ll have to wait in line again for a regular connection. So the flexible connection gives you a temporary but valuable head start.

How quickly does a battery system respond to a curtailment signal?

The Boltainer EMS responds to a digital activation signal within seconds. If the battery is sufficiently charged, it immediately takes over production without any noticeable interruption to business operations.