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What is a dynamic energy contract?
A dynamic energy contract is an energy contract in which the price of electricity changes every 15 minutes. Instead of a fixed or monthly price, with a dynamic contract you pay the actual market price at the moment you use electricity. In Flanders, these prices are determined on the day-ahead market (EPEX Spot), where electricity prices are set every 15 minutes for the following day.
The main difference between a fixed-rate contract (where you always pay the same price) and a variable-rate contract (where the supplier adjusts the price monthly or quarterly) is that, with a dynamic contract, the price fluctuates directly with the market. As a result, electricity can sometimes be very cheap (e.g., on a sunny afternoon when there’s plenty of generation), but it can also be more expensive during times of peak demand (e.g., in the evening when many families are coming home from work).
To sign up for a dynamic contract in Flanders, you need a smart meter. It records your usage every 15 minutes, so your supplier can calculate exactly how much you owe.
How are dynamic energy prices determined?
The quarter-hourly prices of a dynamic energy contract are directly linked to the wholesale electricity market. Every day, a quarterly auction determines the price based on supply and demand for the next 24 hours. These market prices can fluctuate significantly due to factors such as the weather (sun and wind) or peak demand periods (for example, in the evening when many families are cooking and watching TV).
In practice, suppliers base their prices on the day-ahead market. As a consumer, however, you don’t pay that spot price directly; instead, you pay a total rate charged by your energy supplier. That total rate consists of several components:
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Spot Price (EPEX)
The market price per quarter-hour, as determined on the EPEX SPOT day-ahead market. -
Energy Supplier Surcharge: The markup or service fee that your supplier adds for services and administration. -
Grid Costs The rates charged by Elia (high-voltage grid operator) and Fluvius (distribution grid operator) for the transmission and distribution of electricity to your home. -
Levies and Contributions Government levies, such as the contribution for green energy certificates, the federal contribution, and other energy levies established by law. -
VAT
Electricity for residential consumers is currently subject to a 6% VAT rate in Belgium.
Dynamic quarter-hourly rates are on the way
New: A major change is planned for the European electricity market starting in October 2025. In October 2025, the European day-ahead market will switch from hourly rates to 15-minute intervals. Specifically, this means that electricity on the wholesale exchange will no longer be traded on an hourly basis, but rather in 15-minute intervals.
This has been established by the EU in the Clean Energy Package to better respond to rapid fluctuations in the supply of solar and wind energy. Once this change takes effect, dynamic contracts will also be subject to rate changes every quarter-hour.
Negative electricity prices: How is that possible?
A unique feature of dynamic energy contracts is what are known as negative prices. This occurs when more electricity is generated on the market than is consumed—for example, on sunny weekends when demand is low.
For families with a dynamic contract, this means that, in theory, you are rewarded for using electricity. Your energy provider will still charge fixed costs and taxes, so in most cases your energy bill won’t immediately show a negative balance.
Getting the Most Out of Your Dynamic Energy Contract
A dynamic energy contract gives you the best chance of keeping your energy bill low. Because the price changes every quarter-hour, you can strategically shift your usage to times when electricity is cheaper. In 2024, the average Flemish family paid 299 euros less on average with a dynamic contract than with a fixed-rate contract.
Comparison: Dynamic vs. Fixed or Variable Contract
When you sign up for a fixed- or variable-rate energy contract, at first glance you’re choosing certainty. But that certainty comes at a price. That’s because energy suppliers always factor in a risk premium. This is how they hedge against price fluctuations in the energy market. For them, the risks are limited, and for you, it means you consistently pay more than the actual market price.
With a dynamic energy contract, things work differently. You don’t pay a risk premium or a hidden markup. That makes the contract more transparent and, in many cases, more cost-effective.
Shift Your Energy Usage Smartly with a Home Battery
The biggest opportunity to save money with a dynamic energy contract lies in shifting your consumption to the hours when electricity prices are lowest. A home battery plays a crucial role in this, because it can store cheap electricity and use it later during expensive peak hours. With smart management (EMS), this can happen completely automatically. So you don’t have to manually turn all your devices on and off to shift your usage or constantly monitor prices.
By using an energy management system (EMS), your solar panels, home battery, and electrical appliances are connected to each other. The system automatically determines when it is more cost-effective to draw power from the grid, charge your battery, or use your own solar energy.
A home battery knows exactly when to charge or discharge. The EMS monitors market prices and compares them to your current consumption and the output from your solar panels. When the price is low, the battery charges automatically. During expensive peak hours or when your consumption rises, it discharges again, so you don’t have to draw expensive electricity from the grid. That way, you take full advantage of price fluctuations and reap significant benefits from your dynamic energy contract.
Smart Charging for Your Electric Car
An electric car consumes a lot of energy, but at the same time offers a tremendous opportunity to save money with a dynamic energy contract. You can easily schedule EV charging for the cheapest hours of the day without sacrificing any convenience.
With a smart charging station and an EMS, you can fully automate your charging sessions. For example, you can set your car to be charged by 7 a.m. the next morning. The system will then automatically choose the cheapest hours to charge your battery. This way, you avoid charging during the most expensive peak hours (often between 6 p.m. and 9 p.m.).
If you also have solar panels and a home battery, the EMS can charge your car using the solar energy you’ve generated yourself, which further increases your savings.
Key Considerations for a Dynamic Energy Contract
A dynamic energy contract can offer many benefits, but there are also a few things you need to keep in mind:
Flexible consumption is essential
Dynamic rates often offer cheap hours, but they can also be unexpectedly expensive. Families who are unable to adjust their usage therefore run the risk of paying more.
During the evening peak, when most families use a lot of electricity, the price can rise significantly. If you don’t shift your usage, you’ll end up paying the most during the most expensive hours. That’s why it’s important to take advantage of the cheaper times as much as possible—it’s the only way to truly benefit from a dynamic contract. With an energy management system or a smart home battery, this can happen completely automatically. If you don’t do this, there’s a good chance you’ll save less or even end up paying more than you would with a traditional fixed-rate or variable-rate contract.
Uncertainty about the price
A dynamic energy contract does not provide long-term price certainty. While the quarter-hourly prices are known 24 hours in advance, you never know how the market will develop in the coming weeks or months.
During the 2022 energy crisis, we saw how prices could suddenly skyrocket, and that risk applies to both dynamic and variable contracts. With a variable rate, prices are adjusted monthly or quarterly, which also limits predictability. Only a fixed-rate contract offers true certainty, but that often means you pay a higher average price to protect yourself against massive price spikes or an energy crisis. However, such extreme situations are exceptional and occur only rarely.
Solar Panels and a Dynamic Energy Contract
If you only have solar panels and no home battery or energy management system, a dynamic energy contract might not be the best choice. The average dynamic energy price is generally lower than the price of a fixed-rate contract, but this also means the feed-in tariff is lower. That means you might sometimes receive less for the electricity you feed back into the grid from your solar panels than you would with a fixed-rate or variable-rate contract.
Furthermore, dynamic electricity prices are often at their lowest—or even negative—around noon. That’s exactly when your solar panels are producing the most energy. This is because not only your panels, but also those of thousands of other households and businesses, are feeding electricity into the grid en masse at that moment. So you’re mainly feeding electricity into the grid during the hours when electricity prices are low, which limits the return on your solar energy investment.
Fortunately, you can partially solve this with an energy management system. Such a system can intelligently manage your consumption and curtail (limit) your solar panels when prices are low or negative. That way, you avoid having to feed your solar energy into the grid for almost nothing. A home battery makes the situation even better, because you can store the excess solar energy and use it yourself later during expensive peak hours.
Which suppliers offer dynamic energy contracts in Flanders?
The availability of dynamic energy contracts in Flanders has risen sharply in recent years. Whereas just a few years ago only a handful of suppliers offered this type of contract, there are now more than thirty. Both major players such as Engie, Luminus, Eneco, and Octa+, as well as smaller and green suppliers such as Bolt, Frank Energie, and Ecopower, have now included a dynamic rate in their offerings. Large energy suppliers with more than 200,000 customers are even legally required to offer a dynamic contract.
Nevertheless, demand remains low for now: only 0.55% of Flemish customers currently have a dynamic contract. This is mainly because many households still lack sufficient knowledge about dynamic energy rates and how they can benefit from them using smart technology.
Would you like to know which contract is the most cost-effective for your situation? You can easily compare energy contracts yourself using the VREG’s V-test.
If you want to include dynamic contracts in the comparison, you must select “I know my usage” or “I want to upload my usage data” at the start.
Please note: The V-test does not take into account the additional savings you can achieve by combining a home battery with dynamic rates. In practice, your savings are often greater than the simulation indicates.
Conclusion: Is a dynamic energy contract right for you?
A dynamic energy contract can be an excellent choice for families in Flanders who can manage their electricity usage flexibly and are willing to actively adapt to market conditions. They can shift their usage to times when prices are low and thus realize significant savings. So if you have a home battery or an energy management system, you can lower your energy bill even further with a dynamic energy contract.
On the other hand, if you only have solar panels, or if you value predictability and simplicity, you might be better off with a fixed-rate or variable-rate contract. Remember: a dynamic rate isn’t necessarily “better” for everyone—it requires the right profile and behavior.
