Of the eight Homey automations running at Rose Cottage, only one — a flow called "Battery reset" that schedules an overnight grid-charge window — is written entirely in Sonnen's own vocabulary ("operating mode", "Time-of-Use"). The other seven are built on Octopus (via the Kraken Energy app), myenergi's Zappi and Eddi, and a free solar-forecast service, all of which work identically regardless of inverter brand. Own a GivEnergy, Sigenergy, SolarEdge, Tesla or one of a dozen other systems instead of a Sonnen? You can copy seven-eighths of this system verbatim, and only need to rebuild the logic behind three specific Sonnen card types — a grid-power trigger, a battery-mode condition, and a time-of-use schedule action — using your own inverter's equivalent cards.
Why we automated on Homey, not inside one vendor's app
Every piece of kit at Rose Cottage — the solar arrays, the Sonnen battery, the myenergi Zappi and Eddi, the Octopus tariff — ships with its own perfectly good phone app. None of them talk to each other. Sonnen doesn't know what Octopus is charging this hour; myenergi doesn't know the battery is about to hit its export ceiling. Homey Pro sits underneath all of them as a local hub, pulling every device — physical or not — into one place, and lets you wire genuinely cross-brand logic: "if the battery is exporting hard and the Eddi is already on, start the car; once export drops back below 3 kW, shed the car again." That's the actual first flow described below, and no single manufacturer's app could ever express it.
Every energy device at Rose Cottage lives in one Homey zone — Zappi ("Car Charger"), Eddi ("Hot water"), two solar meters, a forecast service, and the four Sonnen devices (battery, grid, household, solar panel). Only the Sonnen tiles are brand-locked; the rest work the same for anyone.
The three pieces that are already universal
Three of the four apps behind this system don't care what inverter or battery you own:
- Octopus, via the Kraken Energy app — reads live import/export tariffs and Intelligent Octopus Go dispatch windows through an Octopus Home Mini. It drives our heating flow entirely on its own: cheap-rate dispatch starting flips the air-conditioning to heating and drops the gas boiler to standby; dispatch ending reverses it. No Sonnen, no myenergi, and it works for any Octopus customer with a Home Mini.
- myenergi (Zappi + Eddi) — our two simplest, most reliable flows are 100% myenergi: a nightly Zappi on/off schedule with a charge-mode set and a retry check, and an Eddi safety-net that turns the diverter back on if it's ever found off when it shouldn't be. Neither flow references the battery at all.
- Forecast.Solar — a free, inverter-independent forecasting service. Our most elaborate flow, which decides overnight whether to hold hot water and EV charging off so they run on tomorrow's solar surplus instead, is driven almost entirely by this forecast — it has exactly one Sonnen card in it, used only as the "solar surplus has actually arrived" trigger.
The one piece that isn't — and how little of the system it touches
Everywhere the system does need something Sonnen-specific, it falls into one of three jobs: reading live grid export/import power, reading or setting the battery's charge/discharge behaviour, or scheduling an overnight Time-of-Use charge window. We counted exactly how many cards in each of our eight production flows fall into that bucket:
Figure — Sonnen-specific cards per flow, out of eight real automations running at Rose Cottage. Five of the eight flows have zero Sonnen dependency at all. Only "Battery reset" — which exists purely to open and close an overnight Time-of-Use charging window — is 100% Sonnen; every other flow keeps its Octopus, myenergi and Forecast.Solar logic untouched.
"Battery reset" — the one flow with no universal cards at all. Every card here is "sonnenBatterie battery": switch to Time-of-Use mode, set an overnight charge window, then switch back to self-consumption at 06:09. The concept (force a grid-charge window overnight, hand control back in the morning) applies to almost any hybrid inverter; the exact wording is Sonnen's own.
"Energy Flow" — the core load-shedding logic, and a more typical case: two Sonnen trigger cards on the left (grid export, battery power) feed straight into ordinary myenergi actions (Eddi, Zappi, a second charger) on the right. Swap the two triggers for your own inverter's grid-meter and battery-power triggers, and the rest of the flow needs no changes.
The three-row cheat sheet
| Sonnen card | What it reads/does | Where to find the equivalent |
|---|---|---|
| Grid power trigger | "Power becomes less/greater than X W" on the grid meter — negative = exporting. | Almost every inverter app (GivEnergy, Sigenergy, SolarEdge, Growatt…) exposes an equivalent grid-meter device with the same style of trigger. No app at all? A Homey Energy Dongle on a P1 smart meter gives you this reading regardless of brand. |
| Battery mode condition | "Power becomes greater than X W" or "Operating mode is …" on the battery device. | Your own battery app's charge/discharge trigger and mode condition — look for "mode", "charging state" or "eco/backup/manual" in its card picker. |
| Time-of-Use schedule action | "Switch operating mode to Time-of-Use" / "Set Time-Of-Use starting…" / "Reset Time-Of-Use". | Your battery app's own schedule or force-charge action. GivEnergy calls this a charge/discharge schedule; Sigenergy exposes a max charge/discharge power action instead of a time window. The idea is universal; the wording never is. |
No Sonnen? Fourteen brands have a Homey app
SolarEdge, Enphase, GivEnergy, Sigenergy, Tesla, Growatt, Fronius, GoodWe, SMA, Solax, Sungrow, LG and BYD all have inverter or battery apps in the Homey App Store — most community-maintained, a few official. Install yours, confirm its devices show live values, then work through the cheat sheet above one flow at a time.
Attaching an AI assistant to the whole thing
Everything above came straight out of the live Flow editor by way of Homey's own MCP connector — the same integration that lets Claude read device status, run and edit flows, and rename devices on our account. It's an official Homey integration (Settings → Customize → Connectors → add https://mcp.athom.com as a custom connector), not a workaround, and it's how we keep this system documented as it evolves rather than letting the flows quietly drift out of sync with reality.
All eight flows, every screenshot, the complete supported-brand table and the step-by-step card-swap method — the reference doc this article is drawn from.
None of this is a sales pitch for Homey specifically — Home Assistant or any other local hub can express the same cross-brand logic. The point that matters, whatever hub you pick, is the one this whole piece is built to prove: automation logic that lives in a neutral hub rather than inside a single manufacturer's app almost always outlives the hardware it was written for.