Your house keeps a diary: how to download your hourly electricity data in Ontario

Here's something most Ontario electricity customers don't know: your utility records your home's electricity use every hour (sometimes more often), and since November 2023, provincial regulation requires them to hand that data over to you, free, in a standard format. It's called Green Button, and it's the closest thing your house has to a diary.

That diary can answer questions your bill can't. The bill tells you how much. The hourly data tells you when — and "when" is where the answers live.

How to get your data

Every rate-regulated utility in Ontario (Alectra, Hydro One, Toronto Hydro, Hydro Ottawa, and the rest) offers this. The steps vary slightly by utility, but the shape is the same:

1. Log in to your utility's customer portal — the same place you view bills.
2. Look for "Green Button," "Download My Data," or "My Energy Use." It's often under usage history or account tools.
3. Choose your date range — grab as much as they'll give you. A full year is ideal because it captures both heating and cooling seasons.
4. Download the file. You'll usually get a choice of XML (the official Green Button format) or CSV (opens in a spreadsheet). Take both if offered.

That's it. No fee, no approval process — the regulation (O. Reg. 633/21) makes this your right as a customer.

If you have a smart thermostat, its data is a bonus — not a requirement

Green Button is the source Kettle's audit is built on, and it works whatever thermostat you have, including none at all. But if you've got a smart thermostat, it can add a second, more direct signal — because unlike the meter, the thermostat usually knows the difference between your heat pump's compressor and its electric backup. How much you can actually get out of it depends a lot on the brand:

• Ecobee. The best of the three for this. Sign in at ecobee.com, open Home IQ, go to System Monitor, and use Download Data to export a CSV. Each export is capped at 31 days, so covering a full winter means downloading a few months back to back — worth it, because the file breaks runtime out by system mode, compressor heat separate from auxiliary/emergency heat, which is exactly the signal behind the aux-heat finding. If we ask for one thing beyond your utility data, this is it.
• Google Nest. The Google Home app's Energy History shows heating and cooling activity, but only the last 10 days, at daily resolution, with no download button. Handy for a quick gut-check, not for a season's worth of evidence — for Nest homes, Green Button carries the analysis.
• Honeywell / Resideo / Total Connect Comfort. These don't offer a comparable export in the consumer app. If yours does show more under Settings or History, send us a screenshot and we'll take it, but don't go looking for a download button that probably isn't there.

None of this changes what we need from you to start: your Green Button file. Thermostat data, when it's available and detailed enough, just sharpens one specific finding — it never replaces the utility data the rest of the audit runs on.

What the diary can tell you

Open the CSV in a spreadsheet and just look. A few patterns show up again and again in Ontario homes:

• The 3 a.m. floor. Whatever your house draws at 3 a.m. — when everyone's asleep and nothing "should" be running — is your base load. Multiply that number by 720 hours and your rate, and that's what standby power costs you every month. In many homes it's larger than people expect.
• Winter spikes that don't match the weather. If your home has a heat pump and you see sharp jumps of several kilowatts on mildly cold days, the electric backup heat may be running when the heat pump alone could handle it — one of the most expensive silent problems a home can have.
• Evening patterns you don't recognize. A load that switches on every evening at the same time is following a schedule. If you can't name it, it's worth finding.
• Whether your rate plan fits your life. Ontario lets most customers choose between time-of-use, tiered, and ultra-low overnight pricing. Which one is cheapest depends entirely on when you use power — which is exactly what this file shows.

When you'd rather not squint at spreadsheets

Kettle exists for exactly this: we read months of your diary with a diagnostic engine built for Ontario homes, and hand you the findings in plain language — each one with a dollar figure and the specific fix. Here's how it works, and what it costs. Your house is talking. It's worth learning to listen.