Green Button in Ontario: How to Download and Use Your Energy Data

Green Button in Ontario lets you download your own electricity and natural gas usage data, usually from a button or link inside your utility's online account. Most electricity customers can get hourly data from their smart meter going back months or years, which is far more useful than the monthly totals printed on a bill.

The editorial team uses this data constantly when helping homeowners decide on price plans, heat pumps, water heaters and other upgrades. This guide explains what Green Button is, how to get your files, and how to read them without special software.

What is Green Button?

Green Button is a North American data standard for energy usage. It defines a common file format so that data from any participating utility can be read by the same tools. There are two versions:

Feature	What it does	Who it suits
Download My Data	You log in to your utility account and download a file of your usage	Anyone who wants to look at their own data in a spreadsheet or tool
Connect My Data	You authorize an app or service to receive your data automatically from the utility	People using an energy-management app, a contractor's analysis tool or a solar or heat pump sizing service

Ontario regulation requires electricity and natural gas distributors to offer Green Button to their customers. Implementation and the level of detail vary, so check your own utility's website or account portal. Programs and rules change; confirm on ontario.ca (opens in a new tab) or with your utility.

How do I download my Green Button data?

The steps are similar for most local distribution companies (LDCs), including Hydro One, Toronto Hydro, Alectra, Hydro Ottawa, Elexicon, Enova and London Hydro, and for Enbridge Gas.

1. Log in to your online account. If you have not created one, you will need your account number and the name on the account.
2. Find the usage section. It may be called "My usage", "Energy use", "Usage history" or similar.
3. Look for the Green Button logo or a "Download my data" link.
4. Choose a date range. Start with the last 12 months to capture a full heating and cooling season.
5. Pick a format. Green Button files are XML. Many utilities also offer CSV, which opens directly in Excel, Google Sheets or Numbers. Choose CSV if available.
6. Save the file and repeat for your gas account if you have one.

Tip: If the export only covers a short range, download several files and combine them. Some portals limit each download to a few months at a time.

What does the data contain?

Utility	Typical interval	What you can learn
Electricity (smart meter)	Hourly, sometimes 15 minutes	Base load, time-of-day patterns, on-peak share, effect of weather
Natural gas	Usually billing period (monthly); some meters provide daily	Heating season use, weather sensitivity, baseline for water heating and cooking

Electricity files typically list each hour's start time and kWh used. Some also include the price period (off-peak, mid-peak, on-peak) and cost. Gas files list m³ per period.

Five practical ways to use your data

1. Find your overnight base load

Sort or chart hourly electricity use and look at the lowest hours, usually between 2 a.m. and 5 a.m. If your home never drops below about 0.4 to 0.5 kWh per hour (400 to 500 W), you likely have significant always-on loads: old fridges or freezers, dehumidifiers, aquarium heaters, network equipment, electronics on standby or a sump pump.

Each 100 W of constant load is about 876 kWh a year, or roughly $130 to $150 at typical all-in Ontario prices (estimate). Our guide to standby power and phantom loads explains how to track them down.

2. Check your on-peak share

Add up the kWh used during on-peak hours. On Time-of-Use, winter weekday on-peak runs 7 to 11 a.m. and 5 to 7 p.m.; summer weekday on-peak runs 11 a.m. to 5 p.m. If more than about 20% of your use falls in on-peak hours, there may be room to shift laundry, dishwashing or EV charging.

3. Test Ultra-Low Overnight before switching

With hourly data you can price your actual year on both TOU and Ultra-Low Overnight (ULO). ULO's overnight rate is 3.7¢/kWh from 11 p.m. to 7 a.m., but its on-peak rate is 37.7¢ on weekdays from 4 to 9 p.m. Our electricity price plan calculator does this comparison using your own usage pattern.

4. Size equipment with real data

Hourly and seasonal data help contractors size heat pumps and evaluate electrical capacity. Winter gas use, combined with heating degree days for your area, gives a reasonable estimate of your home's heating load. Our heat pump sizing calculator gives a rough first estimate. A proper room-by-room load calculation is still the standard for final sizing.

5. Measure the effect of upgrades

Download data before and after a change, such as new attic insulation, an air-sealing job or a heat pump water heater, and compare months with similar weather. This is a simple version of what a Registered Energy Advisor does in a home energy assessment.

Reading your data: a quick example

Here is how one month of hourly data might summarize for a Toronto-area home on TOU in winter. These are illustrative figures.

Measure	Value	What it suggests
Total use	780 kWh	Typical for a home without electric heat
Lowest overnight hour	0.55 kWh	High base load worth investigating
On-peak share	22%	Some room to shift
Highest single hour	6.2 kWh	Likely dryer plus oven plus other loads at once
Weekend share	33%	Weekends are all off-peak on TOU

Privacy and Connect My Data

Connect My Data is convenient, but you are granting a third party ongoing access to detailed information about when you are home and what you use.

• Check who is asking. Only authorize services you have chosen and trust.
• Review the scope. Most authorizations let you choose the accounts, data types and duration.
• Revoke access when finished. Your utility portal should let you see and cancel active authorizations.
• Be wary of unsolicited requests. A door-to-door or phone salesperson asking you to "just connect your account" is a reason to slow down. Our guide to door-to-door energy scams covers common tactics.

Frequently asked questions

Is Green Button free?

Yes. Downloading your own data through your utility's account portal does not cost anything. Some third-party apps that use Connect My Data charge for their own services.

My utility only shows monthly data. Why?

Electricity smart meters record hourly data, but not every portal exposes it in the same way. Look for a separate "hourly" or "interval" option, or call your utility. Gas data is usually monthly because most gas meters are read once per billing period.

Can a renter use Green Button?

If the electricity account is in your name, yes. If utilities are included in your rent or the building is bulk-metered, the data belongs to the account holder.

What if the file opens as a page of code?

That is the XML format. Look for a CSV option in the same portal, or use a free Green Button viewer tool. A spreadsheet can also import XML, though CSV is easier.