Large connections: from 2028, the time of use counts in the network tariff, if the ACM draft goes ahead

On the regional grids, it has so far made no difference to your network tariff when you take electricity from the grid. On TenneT's high-voltage grid, time-based tariffs already apply. If the ACM's draft decision goes ahead, that changes from 2028: using the grid at busy times becomes more expensive and using it at quiet times cheaper. For businesses with a large connection, shifting consumption can therefore save money directly.

What the ACM proposes

On 8 October 2026, the ACM published a draft decision on time-dependent transport tariffs for the regional grids. It applies to connections above 3x80 amperes and is due to take effect on 1 January 2028. A separate draft covers small connections, up to 3x80 amperes, and would take effect on 1 January 2029. For large connections, 50 to 75 percent of the transport tariff becomes time-dependent, and 84 percent in a few specific cases.

The proposal comes from the grid operators jointly, and the ACM largely adopts it. Large users within the same grid area pay the same in total as they do now. The costs are simply divided differently, based on when you use the grid.

Every hour gets a weight

At the heart of the proposal is a weighting factor per hour, from 0.10 in the quietest hours to 1.00 in the busiest. The year is split into three blocks of four months: winter (November to February), summer (May to August) and the transition months. Weekdays and weekends or public holidays each have their own schedule. On winter weekdays, part of the morning and especially the late afternoon and evening count in full; in summer, the middle of the day is the quietest.

The weight works in two ways. For your monthly peak capacity (kWmax), the highest weighted quarter-hour will count, rather than simply the highest quarter-hour. And if you are connected at medium or low voltage, your kWh tariff will also vary by hour and month.

The most expensive and cheapest hours

According to ACM estimates, the highest kWh tariffs on the TS and MS grid levels will be 45 to 75 percent above the current tariff. That only applies in a few hours with the highest weighting factor, in the months November to February. In the hours with the lowest weighting factor, you pay 80 to 85 percent less per kWh than now. According to the same estimates, the tariff for weighted peak capacity on the TS and MS grid levels will be 20 to 40 percent higher than now, but outside the busiest hours your capacity counts for less. Because the weighting factors are lower overall in summer, users with high consumption in the summer months will pay less. For large users on low voltage, the ACM cannot yet make a reliable forecast.

What stays fixed and what happens next

Contracted capacity (kWcontracted) does not become time-dependent. You keep a fixed transport capacity and pay a fixed tariff for it, as you do now. This decision changes nothing for electricity you feed into the grid; the ACM is working on a separate transport tariff for feed-in.

This is still a draft, not a decision. Stakeholders can submit their views until 18 November 2026, in writing, by email or in person. The ACM then aims to take a final decision before the end of this year.

What does this mean for you?

• Find out when your quarter-hour peaks occur. Your quarter-hourly metering data shows how much of your consumption falls in hours with a factor of 1.00.
• Look at which processes you can shift: to the night, to the weekend, or to the early afternoon (hours 13 to 15 as numbered by the ACM, roughly 12.00 to 15.00), which is not in the most expensive categories even in winter.
• Expect higher network costs if you take a lot of electricity on winter weekdays in the late afternoon and evening.
• Want to respond to the draft? You can do so with the ACM until 18 November 2026.
• Follow the final decision at the end of 2026: weighting factors and percentages may still change.

Sources: ACM, draft code decision on time-dependent tariffs for large connections (8 October 2026); ACM, news release on time-dependent network tariffs (8 October 2026).