Negative electricity price
For households with a dynamic energy contract. So you no longer pay to feed in.
How it works
With a dynamic contract your electricity price changes every quarter-hour. When the price for feeding in is negative, you pay to deliver power to the grid. In those quarter-hours we dim your solar panels, and as soon as the price is positive again, we switch them back to full power.
We use the price that applies to you: including your energy supplier’s surcharge, taxes and net metering. Dimming runs through the cloud of your inverter manufacturer, following their guidelines and keeping your warranty intact.
Net metering or not
That depends on net metering: it decides whether you get the tax back on power you feed in. In the app you set which prices apply to you.
In 2026, and the default in the app
below −14 ct
market price per kWh
For every kWh you feed in, you get back the energy tax and VAT you pay on a kWh you use: about 14 cents together. So your compensation only turns negative when the market price drops below about −14 cents. That doesn’t happen often yet.
In the app: prices including tax
From 1 January 2027
below 0 ct
market price per kWh
Net metering ends. You no longer get the tax back on feed-in, but you still pay it on what you use. Every negative market price is then negative for you too, and that’s around 350 hours a year.
In the app: prices excluding tax
Do you feed in more than you use over the year? Then the extra already falls outside net metering today. For that part the bare market price plus your supplier’s surcharge applies, and it was negative for hundreds of hours in 2025.
From 2027
Without net metering, drawing power costs about 14 cents per kWh more than you get for feeding in. When the market price drops below zero, you pay for both.
€ 30–50
saved per year by dimming at negative prices
| Feeding in | you pay 5 ct per kWhthe bare market price |
|---|---|
| Using | you pay 9 ct per kWh−5 ct plus 14 ct tax |
If your panels switch off completely, whatever you use comes from the grid, and that costs money too. With the Zonnedimmer dongle we read your smart meter live and dim exactly as much as you feed in. What you use at home, you simply generate yourself.
About the dongle
Your settings
Choose the price below which we automatically dim your installation. The app uses the prices of your own energy supplier.
Choose how far we dim. Leave part of it on and you generate your own power for what you use at home.
With the dongle you choose the “Minimise feed-in” mode: we then dim no more than you feed in. That works with most brands, not yet with Enphase and Huawei.
Frequently asked questions
You sign up online and connect your inverter, which takes a few minutes. Then you switch on dimming at negative prices in the app settings. How signing up works
No. Zonnedimmer works fully online, through the cloud of your inverter manufacturer. You give permission online, we do the rest.
No. We have agreements with the inverter manufacturers and control your installation according to their guidelines, keeping support and warranty intact. So Zonnedimmer doesn’t affect the warranty or lifespan of your solar panels.
Nothing. The Zonnedimmer app is free and there are no monthly costs.
If your feed-in falls under net metering, your price is only negative for a few hours a year in 2026. You then get the tax back on every kWh you feed in.
Do you feed in more than you use over the year? Then that extra part falls outside net metering. For that part the price was already negative for hundreds of hours in 2025.
From 1 January 2027 net metering ends, and everyone with a dynamic contract pays the bare market price plus the supplier’s surcharge. Dimming at negative prices then quickly saves you € 30 to € 50 a year.
Yes, with the Zonnedimmer dongle. You plug it into the P1 port of your smart meter. That way we see live what you use and feed in, and dim only the power you don’t use yourself. This doesn’t work with Enphase and Huawei yet. About the dongle
Dimming at negative prices is only for dynamic contracts. With a fixed price you don’t pay to feed in when the market price is negative, so there is nothing to save. If you live in one of the areas selected by Enexis, you can join dimming for your grid operator instead. Dimming for your grid operator
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