The Flemish Utility Regulator (Vlaamse Nutsregulator, formerly VREG) currently sees no reason to introduce time-dependent network tariffs — i.e., cheaper grid fees when solar energy is abundant. The energy watchdog doesn’t want to make things more complicated for consumers.
Nearly three years after the so-called ‘capacity tariff’ was introduced (in 2023), which makes households’ grid costs depend partly on their peak power usage, the regulator has no plans to adjust the system.
With the capacity tariff, you pay a higher capacity tariff for peak usage – when running multiple high-consumption appliances simultaneously – while you could actually save money by spreading your electricity consumption more evenly.
Relieve pressure on the grid
The goal was to relieve pressure on the distribution network and avoid everyone plugging in their EVs at the same time, for example, in the evening. However, at times it would be desirable for people to use electricity simultaneously, for example, when solar power is abundant.
To encourage that, time-of-use tariffs (ToU) have been proposed: cheaper grid tariffs during the day, when solar production peaks, and higher ones during the morning and evening peaks. Time-differentiated tariffs have the potential to reduce the extreme peaks on the distribution network, thereby increasing the utilization efficiency of existing infrastructure.
‘Off-peak’ rate
A cheaper ‘off-peak’ rate could apply between 1 p.m. and 5 p.m. from March to November, when solar power is abundant. However, anyone who charges their electric car at full capacity at such times now risks being penalized with a higher capacity tariff. And, conversely, a ‘super-peak’rate could apply during winter evenings, e.g., between 5 p.m. and 8 p.m., when demand is highest.
The Flemish distribution system operator Fluvius recently studied the possibilities of fluctuating grid tariffs throughout the day. The company estimated that intelligent tariff differentiation could reduce peak consumption on the Flemish grid by 10-20%.
Complex
But the Flemish utility regulator is not convinced and not inclined to change the arrangement. The benefits are too uncertain and not yet well quantified. Moreover, such a system would make billing and price structures too complex for households and small businesses.
There’s also a risk of unintended effects — for instance, too many people shifting consumption to ‘cheap hours’, creating new peaks. However, it is not clear how, when, or how much customers will shift their consumption in response to price signals.
Therefore, the regulator will not make changes in the current fixed, non-time-dependent tariff period (2024–2028), though it has asked Fluvius to continue studying possible adjustments for the period after 2029. Fluvius, on its part, suggests exploring phased implementation, perhaps starting with optional tariffs or specific customer segments before full adoption.
