July 1, 2026
Belgium: Fall-Back Flex is temporary. Flexibility is not.
Published by
Olivier Maurissen
Covolt Belgium
Several Flemish companies have received a proposal from Fluvius to sign up for a Fall-Back Flex contract. A handful of companies actually accepted the offer. This blog covers the most important topics related to this.
Why does Fluvius offer Fall-back Flex?
The power grid in Flanders is under pressure. Not because there is a shortage of electricity, but because demand for grid capacity is growing faster than the infrastructure can keep up. Companies are electrifying their processes, installing charging infrastructure, and, above all, requesting larger connections. All of this is happening at the same time, in more and more places.
In areas where Fluvius identifies expected grid congestion, a standard connection is sometimes no longer possible—or at least not in the short term. Fall-Back Flex is the solution Fluvius has developed for this situation: you get the connection or capacity upgrade you want, but you allow Fluvius to temporarily limit your power during exceptional peak periods.
Under normal circumstances, you simply use the full requested power. Only when grid safety is at risk does Fluvius send a modulation signal via the Netflex unit. Your system then has 3 minutes to respond and reduce the power to the agreed-upon setpoint. This control can take place 24/7.
What does the Fall-Back Flex proposal say?
If Fluvius determines that your application falls within a congestion zone, you will receive a quote with Fall-Back Flex terms. That quote consists of three documents.
The zone sheet describes where the grid constraint is located, how much flexible capacity may be required of you, and for what period. It also includes an estimate of the expected annual balancing volumes—which is not binding but is useful for understanding how active your zone is.
The bid form is the document you use to confirm your commitment. In it, you specify your contracted capacity (P_base), the level to which you are willing to reduce output during modulation (P_red), and the price at which you will make that flexible capacity available. Fluvius selects bids based on price and relevance to the grid issue in your zone.
The product sheet describes the rules: technical requirements, performance standards, and what happens in the event of noncompliance.
Once all the documents have been signed and you have given your BRP approval, implementation will begin.
What does the reimbursement structure mean?
There is a fee. Fall-Back Flex operates on a reservation fee basis: you receive a fixed payment for making your flexible capacity available throughout the entire service period. This fee is independent of the number of times Fluvius actually intervenes.
There is no separate activation fee per procedure.
This has an important implication. The compensation is separate from the operational impact of a settlement. If a modulation event coincides with a production peak at your facility, you are responsible for the consequences—including the imbalance created at your energy supplier.
What Is Expected of Your System
This is the point that many companies underestimate. The signal from Fluvius must automatically result in the requested power reduction, without any manual intervention. As the account holder, you are responsible for ensuring that automation is in place on your end.
Fluvius conducts an unannounced reduction test no more than once a year. If you fail, a second unannounced test will follow. If you fail two tests, Fluvius may partially or completely deny you network access.
Can you refuse Fall-back-flex?
Yes. You are not required to accept a Fall-Back Flex proposal. However, that also means that Fluvius will postpone your connection or capacity upgrade until the necessary grid investments in your region have been completed. That timeline is not guaranteed.
For companies with concrete expansion plans, that is rarely a realistic option.
Is this the final proposal?
No. Fall-Back Flex is a temporary solution that Fluvius is implementing while the legal framework for flexible connection agreements (FAO) is still being developed. Once that framework takes effect, your agreement will automatically be converted to a Flexible Connection Agreement. This does not mean the obligation to be flexible will disappear; rather, it will take on a more structural form.
What Covolt Does for You
The Netflex cabinet sends a signal. But your system must respond within 3 minutes—automatically, correctly, and with proper documentation.
Covolt’s energy management system provides that automatic response. Batteries, charging infrastructure, flexible production assets: the EMS coordinates the response to the modulation signal without manual intervention.
But the real benefit of Covolt Horizon lies in the hours when Fluvius does not intervene. Covolt continuously uses your assets to optimize self-consumption, manage peak capacity to lower your capacity rate, and generate revenue on various energy markets.
Fall-Back Flex is temporary. However, the expectation that your system will respond flexibly and automatically to grid signals is not.
Learn more?
Would you like to know what Fall-Back Flex means for your site in practical terms? Contact us or schedule a no-obligation consultation.
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