GHG emissions from utility data: scope 1 and 2

Most greenhouse gas reports do not stall on the math. They stall on the data. The formula for scope 1 and scope 2 emissions is short and public, but it depends on having complete, accurate consumption for every account you operate. Miss a few meters, mix up units, or line the periods up wrong, and every downstream number inherits the error. This guide walks through the basic method, where the real emission factors come from in the US and Canada, and the data quality you need before the arithmetic can be trusted.

The formula is simple: activity data times emission factor

Under the GHG Protocol, an organization's emissions are split into scopes. Scope 1 covers direct emissions from sources you own or control, which for most buildings means burning natural gas on site for heating. Scope 2 covers indirect emissions from the electricity, steam, heating, or cooling you purchase. Both are calculated the same way:

"Emissions = activity data (energy consumed) times an emission factor."

Natural gas (scope 1): multiply gas consumed (in therms, cubic metres, or gigajoules) by a combustion emission factor for natural gas.
Purchased electricity (scope 2): multiply electricity consumed (in kilowatt hours) by a grid emission factor for the region that supplies you.

The activity data in both lines is exactly what appears on your utility bills and meter reads. That is why complete, standardized consumption data is the real foundation of an emissions calculation, not an afterthought.

Scope 2 electricity: location-based versus market-based

Electricity has a wrinkle. The GHG Protocol Scope 2 Guidance asks organizations to report scope 2 using two methods:

Location-based: uses the average emission factor of the grid you physically draw from, over a defined geography and period. In the US, the common source for these factors is the EPA eGRID database.
Market-based: reflects the emissions of the electricity you have specifically contracted for, through instruments such as renewable energy certificates or supplier specific rates, and falls back to a residual mix or location-based factor where no contractual instrument exists.

The Scope 2 Guidance is clear that where the choice exists, both figures should be reported side by side. Either way, the consumption figure (the kilowatt hours) is the same input; what changes is the factor you apply to it.

Getting that consumption input complete for every account is the part teams underestimate. Start a pilot at ezgb.ca and we will assemble standardized electricity and gas consumption across your whole portfolio, so the factor is the only variable you are deciding on.

Where real emission factors come from

United States

For location-based electricity, the US EPA publishes the Emissions and Generation Resource Integrated Database (eGRID), which reports grid emission rates by region across the country. For natural gas and other fuels, the EPA maintains default combustion emission factors in its GHG Emission Factors Hub, which it updates for organizational greenhouse gas reporting. These are the primary references most US calculations point to.

Canada

In Canada, emission factors come from Environment and Climate Change Canada's National Inventory Report and official greenhouse gas inventory, whose annexes publish fuel emission factors and the greenhouse gas intensity of electricity by province and territory. Those provincial differences are large. The Canada Energy Regulator reports that the national grid averaged about 100 grams of CO2 equivalent per kilowatt hour in 2022, down 55 percent from 220 grams in 2005, but the average hides a wide spread. Quebec's mostly hydro grid was around 1.2 grams of CO2 equivalent per kilowatt hour, while provinces that lean on natural gas are far higher. The same kilowatt hour produces very different emissions depending on where it is consumed, which is why account level location data matters.

The Canadian numbers, and the table they come from

If you report in Canada and want a defensible number rather than a rounded guess, Environment and Climate Change Canada publishes Emission factors and reference values, currently version 4.0 dated September 9, 2026. It sets out electricity consumption intensities by province and fuel combustion factors in one place, each in a numbered table you can cite in a methodology note. The Ontario rows look like this:

Fuel or grid	Value	Unit	Published in
Ontario grid electricity, 2023 and 2024	30	g CO2e per kWh	Table 5.1
Ontario grid electricity, 2025	38	g CO2e per kWh	Table 5.2
Ontario grid electricity, 2026	59	g CO2e per kWh	Table 5.3
Ontario grid electricity, 2027	73	g CO2e per kWh	Table 5.4
Marketable natural gas, Ontario	1 921	g CO2 per cubic metre	Table 1.1

Two things to note before you paste those into a spreadsheet. First, these values are published for the federal greenhouse gas offset system and the output-based pricing system, and the later years are set in advance for compliance planning rather than measured after the fact, so they are not a record of what the grid actually did in that year. Second, your own reporting programme may require a different source, such as the National Inventory Report annexes or a factor your jurisdiction specifies. Record the version and table number you used, and keep the consumption data that sits underneath it.

The hard part: data quality prerequisites

Because emissions are consumption times a factor, any weakness in the consumption data flows straight into the result. Before you calculate, the data should clear a few checks:

Complete account coverage: every meter and account in the reporting boundary is included, with none quietly missing.
No gaps or overlaps: the reporting period is fully covered, with no missing months and no double counted bills.
Correct and consistent units: kilowatt hours for electricity, and a single consistent unit for gas, converted carefully where bills differ.
Aligned periods: billing periods mapped to the calendar period you are reporting, since utility cycles rarely match month ends.
Consumption, not just cost: the actual energy used, separated from dollar charges, taxes, and delivery fees.
Stable identifiers: meters that were swapped or renumbered are still tracked to the right site.

Assembling that by hand across dozens of accounts is where most of the effort goes, and where most of the errors creep in. Tell us which accounts you report on at ezgb.ca/pricing and we will handle the collection and standardization so the consumption side is clean before you ever apply a factor.

How EZGB gives you trustworthy activity data

EZGB (Easy Green Button Connector) gathers utility consumption and billing data from authorized utility connections, from Green Button (whose Download My Data and Connect My Data methods are built on the NAESB ESPI standard), and from PDF or scanned bills through BillScan. It standardizes electricity, gas, and water into consistent units and clean fields, with up to two years of history where available, and delivers it by REST API, CSV, or SFTP.

To be clear about the boundary: EZGB provides the clean, standardized consumption and billing data that your emissions math sits on. It does not produce your official inventory, apply your chosen emission factors, or make any determination about compliance or certification. You, or your sustainability advisor, select the factors and methods and run the calculation. What EZGB removes is the data gathering and cleanup that usually blocks that work.

A worked example (illustrative)

Suppose an Ontario portfolio consumed 1,000,000 kilowatt hours of grid electricity in 2024. Applying the Ontario consumption intensity of 30 grams of CO2 equivalent per kilowatt hour from Table 5.1 gives 30 tonnes of CO2 equivalent for scope 2 (1,000,000 kWh times 30 g, divided by 1,000,000 g per tonne). Add 100,000 cubic metres of natural gas at 1 921 grams of CO2 per cubic metre, from Table 1.1 of the same document, and the scope 1 line comes to about 192 tonnes of CO2. In practice you would use the factor for the specific province and year, not the national average, and you would add a separate scope 1 line for natural gas using an EPA or NIR combustion factor. The structure is the same in every case: complete consumption, multiplied by the right published factor.

Book a walkthrough at ezgb.ca, and we will set up a feed that keeps your consumption data current, so each reporting cycle starts with trustworthy activity data instead of a spreadsheet scramble.

Sources

Source: ghgprotocol.org