See what electricity actually costs you, hour by hour — and when to charge. Real US utility tariffs (time-of-use, tiered, seasonal, holidays) as live Home Assistant sensors: a $/kWh price entity for the Energy Dashboard and a cheapest-charge-window sensor for EVs and batteries. 100% local — no cloud, no API key, no account.

EU installs get dynamic day-ahead prices (Nordpool, Octopus…). US rates hide in utility PDF rate sheets — time-of-use windows, seasons, baseline tiers, holiday rules. Ratebook turns those PDFs into data and prices every hour of your day with a deterministic, engine-tested rate engine, so your Energy Dashboard tracks dollars that match your bill.

30 plans across 16 utilities, every one audited against the utility's current rate sheet (July 2026) with sources and a last_verified date in the tariff file. Pick your plan in the config flow — no YAML, no JSON:

TOU plans whose rate sheets define holiday off-peak pricing carry those holiday rules (on PECO's TOU, Labor Day afternoon really is off-peak), and tiered plans price at your tier. How big are the swings? On SDG&E's EV-TOU-5, a peak kWh costs 6.2× the overnight rate ($0.79 vs $0.13) — charging a 40 kWh EV in the wrong window is ~$27. Con Edison's SC-1 Rate III hits $1.18/kWh on summer weekday afternoons vs $0.13 overnight.

Utility not listed? Request it — a rate-sheet link is all that's needed, and new tariffs ship in days, not quarters. Or paste your own tariff JSON into the config flow.

HACS: click the badge above (or HACS → ⋮ → Custom repositories → add https://github.com/cbetz/ratebook-homeassistant, category Integration), install Ratebook, restart. (Submitted to the HACS default store — hacs/default#8837 — after which the custom-repo step goes away.)

Manual: copy custom_components/ratebook into your config/custom_components/, restart.

Then: Settings → Devices & Services → Add Integration → Ratebook, pick your utility plan, and (tiered plans) the tier your bill usually lands in.

1. Settings → Dashboards → Energy.
2. Under Electricity grid → Grid consumption, add your consumption sensor (from your utility meter, Emporia/Sense/Shelly CT clamps, or a smart-meter integration).
3. For "Use an entity with current price", pick sensor.ratebook_electricity_price.

The dashboard now accrues cost per hour at your tariff's real marginal rate — peak hours cost more, off-peak less, exactly as your bill will. (Ratebook supplies the price; the consumption sensor comes from whatever measures your usage.)

• sensor.ratebook_electricity_price — current marginal price (USD/kWh). Attributes:
  • raw_today / raw_tomorrow — hourly [{start, end, value}], the Nordpool-compatible shape existing charging automations, blueprints, and ApexCharts configs consume. tomorrow_valid is always true: unlike day-ahead markets, tomorrow's tariff prices are known all day.
  • forecast — 48h [{start, end, value}] in evcc's custom-tariff shape (recipe); also works for EMHASS (recipe).
  • today / tomorrow — hourly [{start, price}] (legacy shape, kept for compatibility).
  • today_is_holiday / tomorrow_is_holiday — whether the tariff's holiday rule prices the day off-peak.
  • tier — the 1-based tier prices are computed at (tiered plans).
• sensor.ratebook_cheapest_charge_window — start of the cheapest upcoming contiguous charge block, searched from now through the end of tomorrow (timestamp). Attributes: end, avg_rate, hours.

A copy-paste dashboard (gauge, charge-window card, price history, optional ApexCharts hourly curve) ships in examples/dashboard.yaml.

If your utility is in URDB and you're happy with URDB freshness, ha-openei is a fine choice — Ratebook exists for when the numbers have to match the bill.

• Prices are the tariff's energy marginal price — the time-of-use signal. Demand charges aren't modeled; on tiered plans the price is computed at the tier you pick in the config (not tracked against your cumulative monthly usage).
• Some deregulated-state tariffs are delivery + default-supply; if you buy generation from a third-party supplier, your all-in price differs. Every bundled tariff lists its sources and a last_verified date — check one bill against it, and file a correction if anything is off.

This repository is the HACS distribution mirror — a generated copy of cbetz/ratebook (packages/ratebook-homeassistant), where the engine, dataset, tests, and issue tracker live. Please file issues and PRs there.

Apache-2.0. Tariff data: CC0-1.0.