About wattslot

wattslot shows what electricity really costs in each quarter hour — spot price, grid tariff, taxes and VAT — and when it’s cheapest to run the dishwasher or washing machine, or to charge the car.

Why

Most apps show the spot price. But the grid tariff alone can be several times higher in the evening peak than at night, so the spot price on its own often points at the wrong hour. wattslot adds it all up.

Who

wattslot is built by Mateo Kadiu, a software engineer. More at mateokadiu.com.

Open source

The code is public on GitHub: the libraries under Apache-2.0, the apps under AGPL-3.0. Anyone can see how the price is calculated, report a mistake or run their own copy.

Independent

wattslot isn’t affiliated with Energinet, any grid company or any electricity supplier.

Contact

Found a wrong price, or is your grid company missing? Open an issue on GitHub.