TapHome
Planned Feature

Plan devices by tomorrow's electricity price: cheapest hours, negative prices and tariffs

TapHome would know the day-ahead spot prices and your grid tariff, so that smart rules and scripts could run devices in the cheapest hours, prepare for negative prices and avoid expensive ones.

Planned. It will not be part of TapHome 2026.1; expect months rather than weeks. We cannot promise an exact date yet.
Bar chart of hourly day-ahead electricity prices over one day: high in the morning and evening, negative around noon (green bars), with a dashed frame around the cheapest three-hour window.
Bar chart of hourly day-ahead electricity prices over one day: high in the morning and evening, negative around noon (green bars), with a dashed frame around the cheapest three-hour window.

Why and how you would use it

With a spot price contract, electricity costs something different every quarter of an hour, and the prices for the next day are known in the afternoon before. On sunny days they often drop below zero around noon. Installers want TapHome to plan with these prices: run the water heater, the heat pump or the EV charger when electricity is cheapest, charge the battery from the grid when the price is negative, and leave expensive hours alone.

A typical case: a hotel with solar panels, a battery and a generator whose waste heat warms the wellness area. At 7:00 the hotel wants to know whether the price will turn negative later that day, and for how long. If yes, the generator stays off in the morning, the heating elements follow the solar production, and the batteries charge from the grid while the price is below zero. Today TapHome knows the current price and a few statistics of the day, but it cannot look ahead like that.

The chart shows such a day. Green hours have a negative price; the dashed frame is the cheapest three-hour window, the one a smart rule would pick for a device that has to run three hours.

Sketch of a phone screen Spot price: the price now is minus 25 euros per megawatt hour, a chip says Negative now, a bar chart shows today and tomorrow with green negative bars around noon, and rows list the negative price from 11:00 to 15:00, the cheapest 3 hours and the lowest and highest price.
Sketch of a phone screen Grid tariff: time period Workday and weekend, and a list of times with off-peak and on-peak prices in euros per kilowatt hour.

This is how it could look in the app. The price device would show today and tomorrow as bars, mark the time now, and say when the price is negative and which hours are cheapest. The grid tariff would be set by time of day, separately for workdays and the weekend, so that the price in smart rules is the price you really pay. The screens are a sketch of the idea, not the final design.

TodayWith this idea
Price sourceTemplateBuilt in
Plan aheadFixed template devicesScripts and smart rules
Negative price windowNot shownWhen and how long
Grid tariffNot includedIncluded

What will be possible

This idea is planned. It will not be part of TapHome 2026.1, and the details below may still change.

  • Prices without a template. TapHome would download the day-ahead spot prices of your market by itself, for today and, once published, for tomorrow.
  • Your real price. You could add your grid tariff, for example a cheaper night rate, different on workdays and at the weekend, so that decisions follow what you really pay, not only the market price.
  • Look ahead in scripts and smart rules. Find the cheapest window of a given length, the rank of a period by price, or when the price is highest and lowest in the coming hours.
  • Negative price windows. Know in advance whether and when the price turns negative, and for how long, so that you can prepare loads and batteries for it.

What will not be possible

  • Prices further ahead than the market publishes. Day-ahead prices are known for the next day only, usually from the afternoon. Before that, tomorrow is unknown.
  • Every market at once. A first version would cover only some day-ahead markets. Tell us in the comments which market you need.
  • A plan made without you. TapHome would give the prices and the tools; which device runs when stays your decision in smart rules and scripts.
  • A price forecast. TapHome would use the published market prices, not guess future prices of its own.

How to solve it today

  • Spot price templates. The OKTE spot prices, OTE-CR spot prices and Nanogreen spot prices templates give the current price, the rank of the current period, the cheapest period of the day and the lowest, highest and average price, also in a time window of your choice.
  • Will the price turn negative today? A smart rule can compare the lowest price of the day with zero. How long the negative prices last is not one of the template devices.
  • Use the surplus. The Energy Manager switches devices by the power available from solar panels, independent of the price.

Learn more

Do you have a spot price contract? Tell us what you would plan with future prices: vote for this idea, follow it for updates and answer the poll below.

What would you plan with future electricity prices?

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Related

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Status history

  • Nov 4, 2026 Planned Published

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Ideas describe direction, not commitments. We do not publish dates; released features are announced in the release notes.