Electricity prices quarter hour by quarter hour.

The spot price is set the day before, for every quarter hour.

Because since 1 October 2025 the power exchange has set the spot price for every quarter hour instead of every hour. The prices for the next day arrive around 13:00, which gives 96 prices on a normal day, 92 or 100 when the clocks change.

Denmark is split into two price areas: DK1 west of the Great Belt and DK2 east of it. The prices are often the same, but not always. GridZeno gets them from Energinet's official datasets for both areas.

The spot price is rarely the price you pay.

The buying price is the spot price plus your grid company's grid tariff, Energinet's system tariff and transmission tariff, the electricity tax and your electricity supplier's mark-up, with 25% VAT on top of it all.

Spot price

Changes every quarter hour.

Grid tariff

Your grid company's price for transporting the power. Changes with the time of day and the season.

System tariff and transmission grid tariff

Energinet's, the same for everyone in Denmark. 7.2 and 4.3 øre per kWh in 2026.

Electricity tax

Set by law. 0.8 øre per kWh in 2026.

Electricity supplier's fee

What your electricity supplier adds per kWh.

VAT

25% of the total.

The fixed subscription with the electricity supplier isn't part of the kWh price, because it's the same however much power you use. See a worked example.

The grid tariff changes at fixed times of day, and that can move the price more than the spot price does.

Low load

00:00 to 06:00. The same price all year.

High load

06:00 to 17:00 and 21:00 to 24:00.

Peak load

17:00 to 21:00. The most expensive.

Most grid companies have used this division, Tarifmodel 3.0, since 2023. From October to March, high load and peak load are more expensive than in summer, peak load often more than twice as expensive. That's why the quarter hour starting at 17:00 can cost considerably more than the quarter hour at 16:45, even if the spot price is the same.

Not all grid companies follow the model, and some have the same price around the clock. GridZeno gets your grid company's own rates hour by hour from Energinet's DataHub.

The same path, just in reverse, and without VAT on the spot price.

For the power you sell, you get the spot price minus Energinet's feed-in tariff and balancing tariff, your grid company's feed-in tariff and your buyer's trading fee, with VAT on the deductions. Grid tariff, system tariff and electricity tax are only something you pay when you buy.

That's why a kWh you sell is almost always worth far less than a kWh you avoid buying. That's the whole reason why it pays to use your own solar power yourself, and to store it in a battery for the evening.

The difference between two quarter hours has to be bigger than the loss in the battery.

Power that goes into and out of a battery loses some on the way. On our own system, we have measured around 10 to 15% for a round trip in and out. If you buy at DKK 1.00 per kWh and lose 15%, each kWh you get back out costs around DKK 1.18. And the battery wears a little every time it's used.

That's why GridZeno only charges from the grid for the sake of the price when the plan's own calculation shows that it saves at least 25 øre after loss and wear. And it calculates with the buying price and the selling price for every quarter hour, not with the spot price alone. The plan is carried out by the GridZeno Dongle, which sits at your inverter.