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 enormously on the brand — and the honest summary is that one brand makes it easy and the rest mostly don't:

• Ecobee. The best of the lot for this, by a wide margin. 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. More nuanced than it first appears, so it's worth being precise. Inside the Google Home app, no: Energy History shows heating and cooling activity for the last 10 days only, at daily resolution, with no download button. But Nest data can be exported — through Google Takeout (takeout.google.com, tick Nest), which most people never think to try. The catch is what's actually in the archive. You generally get your indoor temperature, humidity and setpoint history as CSVs, which is real and useful. What you don't reliably get is runtime: the file carrying furnace and heat-pump activity has only ever covered the same trailing 10 days, owners have reported it vanishing from their archives altogether, and there have been long stretches where Nest exports came back empty or simply failed. Google's developer API doesn't rescue it either — Device Access (a one-time US$5 registration) reports what your thermostat is doing right now, not what it did last February. So: try Takeout, and send us whatever comes out — a winter of indoor temperatures tells us more than nothing. But for the aux-versus-compressor question, in a Nest home Green Button carries the analysis.
• Daikin One+ — plenty to see, nothing to download. If your heat pump came with its own thermostat, this is usually where you land, and Daikin actually gives you more than most manufacturers do. It just never gives you a file. There are two places to look. The first is your inbox: the system emails a monthly energy report, and those have been arriving since the day it was commissioned, quietly piling up whether or not you noticed. Search your mail for Daikin and you may find several winters sitting there — we've used exactly these on a real house and they earned their keep. The second is the Skyport app's energy use screen, which is considerably better than its reputation: daily kWh bars across a full month, split out by zone, with each day's peak outdoor temperature plotted on the same chart, a month-over-month comparison, and arrows to page back through earlier months. Daily consumption set against daily outdoor temperature is genuinely the right shape for this work — it's how you see a system that behaves itself in mild weather and falls off a cliff below a certain temperature. The catch is that there's no download button anywhere in it, so the only way out is to screenshot each month as you page back. Tedious, but it works, and we'll gladly take screenshots. One caveat the app states about itself and we'll repeat: those figures are estimated from what your system did, not metered readings. That's no reason to ignore them — but it is a reason to lay them alongside your Green Button data, because where the estimate and the meter disagree, the gap is sometimes the finding. The same shape holds for Carrier Infinity, Lennox iComfort, Trane and Mitsubishi: real detail on screen, no way to export it. If any of them mails you something periodic, keep it.
• 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.

There's a pattern in that list worth naming. A thermostat is sold as a comfort device, not as an instrument, so most manufacturers keep just enough history to draw a nice chart in the app and no more. What history does survive is whatever got mailed to you and whatever you thought to screenshot — which is a ridiculous way to keep records about your own house, and also, for now, the only way. Worth a look before you conclude you have nothing. Your utility, meanwhile, is obliged to hand you years of it on request. That's the whole reason Kettle is built on meter data rather than on thermostats.

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.