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Curious Cat Consulting

Ohm Assistant energy card for Home Assistant

Power and energy use by room, as charts you can read at a glance, including the power nothing is tracking.

For
Open source, for Home Assistant users
When
2025
GitHub
A stacked line chart of one room’s power use by circuit over a day

The situation

Home Assistant has plenty of energy data, but per-room power and daily trends are hard to read from individual sensors.

What I built

A card that discovers power and energy sensors by area and charts them as lines, stacked lines or stacked bars, with watts and kWh together. The bar charts also calculate the power that no sensor accounts for.

What changed

393 tracked downloads as of May 2026, listed in HACS by default.

Built with

  • TypeScript
  • Lit
  • Home Assistant
  • Lovelace
  • HACS
  • GitHub Actions
  • Chart.js

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