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Dynamic Electricity Tariffs

Franzl knows tomorrow's market prices, and shifts charging and heating into the hours when the kilowatt-hour costs the least.

What Franzl does

With a dynamic tariff (aWATTar in Austria and Germany, for example), your electricity price changes hourly with the market. At night, and when there's a lot of wind, it's often just a fraction of the evening price. Franzl fetches the prices for the next 48 hours and plans your flexible loads around them:

• The car charges in the overnight low instead of the evening peak, and is still full on time, because you tell Franzl by when.
• Water heater and heat pump heat ahead of time when power is cheap, and hold back when it's expensive, within the comfort limits you've set.
• The home battery can even run arbitrage when it makes sense: charge cheap, discharge expensive, provided your storage system actively supports it (which ones do is listed in the device database).

A flat rate or a peak/off-peak tariff (HT/NT) works just as well, of course; Franzl then optimizes against your two price tiers, or focuses entirely on the sun.

A deadline, not a timer

The difference from a timer switch: you say what you need, not when something should run. "Car at 80% by 6:00 am": Franzl picks the cheapest hours for that itself, fresh every night, depending on prices and tomorrow's solar forecast. If the morning turns out sunny, it waits for the rest to come from the roof.

Honestly calculated

Franzl reports savings only for measured kilowatt-hours, never for planned ones. And it calculates against your real tariff, including the feed-in tariff, not against some fictional reference price. Whether switching to a dynamic tariff pays off for you depends on how flexible you can be: in the knowledge article, we work through it soberly, including the cases where it doesn't pay off.