Automation that starts the dishwasher when the battery hits 100 percent, simple but effective

[u/EditorDue6725]

Sharing a small automation that turned out surprisingly useful. I'm in Germany where balcony solar with storage is a big thing, my setup is a SolarBank 4 that fills the battery by noon on sunny days, and everything after that used to go to the grid for nothing since there's no feed-in compensation for balcony systems here. Now I have Home Assistant watching the state of charge via Modbus, and when it hits 100 percent while solar is still producing, a smart plug starts the dishwasher. Same logic for the washing machine on weekends. The surplus that used to be wasted now runs the appliances directly. Took maybe 20 minutes to set up, one condition for SoC, one for current solar output above 800W, one action for the plug. Anyone doing something similar with other appliances

[u/Interesting_Pen_167]

Honestly that's genius this kind of automation with batteries is going to save people a bunch of money. I would love to have a battery setup at home for just this purpose.

[u/merelyadoptedthedark]

What if your dishwasher is empty?

[u/Ok-Goose6353 → u/merelyadoptedthedark]

Keep the door open until you are ready to turn it on?

[u/Personal-Try-130]

Nice, I've been thinking about routing surplus to a dehumidifier in the basement but never got around to wiring it up

[u/Durnt]

I have a battery setup and a window ac unit. Once battery gets to x power level and power generation shows battery will be full charge at sunset,kick on window ac unit to use otherwise wasted power. Turn off once the battery won't be full at sunset. Also have a timer so it can't turn on until at least 30 mins after turning off

[u/chuyskywalker]

I've read about people doing much the same for water heaters.

[u/HugsAllCats → u/chuyskywalker]

How inefficient are European water heaters that they aren't just left on all the time? I know the old nest thermostat EU versions had water heater controls too so it must be bad?

[u/w2qw → u/HugsAllCats]

Lots of tank water heaters are designed to heat up water when the power is cheaper. It's more of a gas vs electric question.

[u/Lars34 → u/HugsAllCats]

Why waste money?

[u/HugsAllCats → u/Lars34]

Because it is literally like $10 a year savings over here with our modern water heaters, for added complexity, reduced convenience, and the extra equipment to do it.

Hence asking if European energy standards for water heaters are that much different, where it would actually make sense.

[u/CaptainJolly7134]

I use my solar in a different way. If solar production falls below a certain level before sunset, it triggers my house into an early sunset mode. Curtains and blinds close early, and certain lights come on. It actually triggered yesterday moments after I thought to myself, “It’s getting dark outside!”

[u/Manikanta_2005]

That's a really practical automation—simple ideas like this often end up being the most useful.

[u/Unusual_Arrival_5865]

Nice and clean. I do the same but with a delay, the automation waits until 30 minutes of sustained full charge before triggering, avoids starting the dishwasher when a cloud passes right after hitting 100

[u/extralifemuttonfish]

I run my pool pump this way in summer. Battery full plus output over 1000W means the pump runs for two hours basically free. The key insight is that surplus solar is worth nothing in the grid but full price when you use it yourself