An electricity emission factor is the figure that converts a company's electricity consumption (in kWh or MWh) into tonnes of CO2 equivalent for scope 2 emissions. Because every country has a different generation mix, with more or less hydro, coal, gas or renewables, each country publishes its own factor, and that factor changes every year. This guide brings together what we could verify against the official sources for Colombia, Mexico, Chile and Peru, with the exact date and resolution where one exists, and says plainly where we could not confirm a specific figure.
What it measures and what it's for
The electricity emission factor expresses, in tonnes of CO2 equivalent per megawatt-hour (tCO2eq/MWh), the average carbon intensity of the electricity flowing through a country's grid. It's used in the location-based method for scope 2: multiplying the electricity consumption read off invoices by this factor gives the associated indirect emission. The difference between the location-based and market-based methods, and when to use each, is covered in our guide on the differences between scope 1, 2 and 3 emissions. What matters for this guide is that the correct factor isn't a universal number: it depends on the country, the grid year being measured, and sometimes the purpose of the calculation, as the Colombian case shows clearly below.
Colombia: UPME's factor, and why there's more than one
Colombia's Unidad de Planeación Minero Energética (UPME) updates the emission factor of the National Interconnected System (SIN) every year. UPME Resolution 000085 of 2026, dated 23 February 2026, updated the factor for the year 2024 and sets, within a single article, different values depending on what the factor will be used for:
| Use | Value (tCO2eq/MWh) |
|---|---|
| GHG inventories (the one that applies to corporate carbon footprints) | 0.220 |
| CDM, first accreditation period, wind and solar plants | 0.660 |
| CDM, first accreditation period, non-wind/non-solar projects | 0.607 |
| CDM, second and third accreditation periods, non-wind/non-solar projects | 0.554 |
The first three values are Clean Development Mechanism (CDM) factors, meant to calculate the emission reduction a renewable generation or energy efficiency project can certify against what the grid would otherwise have emitted; they're calculated under the UNFCCC CDM Executive Board's methodology (UNFCCC/CDM-EB 35). The one that applies to a company reporting its corporate footprint, not a reduction project, is the GHG inventory factor: 0.220 tCO2eq/MWh. Mixing the two up is a real and common mistake: using the CDM factor for a corporate inventory triples or quadruples the reported scope 2 emission.
The obligation to update the factor annually comes from article 3 of MME Resolution 91304 of 2014, which assigned that function to UPME. The resolution takes effect the day after its publication in the Diario Oficial.
Mexico: the National Electric System factor (FE-SEN)
In Mexico, the National Electric System Emission Factor (Factor de Emisión del Sistema Eléctrico Nacional, FE-SEN) is used to calculate the indirect greenhouse gas emissions from electricity consumption reported to the National Emissions Registry (RENE) and in the Annual Operating Report (COA). It's a joint notice: the Energy Regulatory Commission (CRE) calculates it under article 12 of the Regulation to the Energy Transition Law, and the Ministry of Environment and Natural Resources (SEMARNAT) communicates it to reporting establishments. The two most recent published values:
| Factor year | Value | Notice publication date |
|---|---|---|
| 2023 | 0.438 tCO2e/MWh | 28 February 2024 |
| 2024 | 0.444 tCO2e/MWh | 28 February 2025 |
There's an important operational detail here for anyone closing out their 2026 report: a SEMARNAT notice dated 29 May 2026 stated that the 2025 factor was still being estimated and published, and that this task had moved to the Ministry of Energy (previously CRE handled it). Until the 2025 factor is published, that same notice instructs establishments to use the 2024 factor (0.444 tCO2e/MWh) for the 2026 COA reporting period, which runs through 30 June. If your company is calculating scope 2 for that report, that's the value to use until the 2025 one is published.
The legal basis is the General Climate Change Law (article 7, section XXXIV) and the Regulation to the General Climate Change Law on the National Emissions Registry (article 87, sections I to IV), which set the reporting thresholds, calculation methodologies and the monitoring, reporting and verification system.
Chile: the National Electric System factor, published by the Ministry of Energy
In Chile, the body that publishes the GHG emission factor of the National Electric System is the Ministry of Energy, within its climate change environmental indicators section. The factor is calculated from the generation mix reported to the National Electric Coordinator, the system operator. We were not able to verify a current, in-force numeric value against that official document within the sources reachable while writing this guide: Chilean environmental and sustainability regulation requires this figure to be current for any scope 2 inventory, so if your company reports emissions in Chile, the right step is to check the Ministry of Energy's environmental indicators page directly and note the date you consulted it, rather than working from a secondary source or an older year without confirming it's still current.
Peru: two agencies, two different purposes
Peru has two sources worth keeping separate. The Ministry of Energy and Mines (MINEM), through its energy efficiency platform, publishes a specific document of national emission factors for electricity consumption, meant for a company to calculate its indirect emissions from using the grid (the National Interconnected Electric System, SEIN). The Ministry of the Environment (MINAM), for its part, runs Infocarbono, the national greenhouse gas inventory system, which also reports electricity generation within the energy sector, but with a methodology geared toward the aggregated national inventory, not the per-MWh consumption factor an individual company needs. As with Chile, we couldn't extract a current numeric value from MINEM's document within the sources we managed to reach; what is clear, and worth noting, is which of the two agencies applies depending on the purpose of the calculation. If your company already takes part in the national carbon footprint programme, our guide to registering with Huella de Carbono Perú covers that process, which is a separate instrument from this electricity consumption factor.
What to do when the agency hasn't published the year's factor yet
Mexico's 2026 case, with the 2025 factor still unpublished in May, isn't an exception: it's common for a given year's figure to be published several months after that year closes, because the actual generation from every plant on the system has to be consolidated first. Across the four jurisdictions in this guide, one consistent practice holds:
- Use the most recent officially published factor, even if it's for a year earlier than the one you're reporting, rather than an estimated or self-interpolated value.
- Document which factor year you used and which notice or resolution it comes from, so whoever reviews the inventory can verify it without having to redo the search.
- Check whether the agency issued explicit guidance, as SEMARNAT did in Mexico by stating which factor to use while the current year's isn't ready; sometimes that guidance exists and removes the ambiguity.
- Don't swap the national factor for a generic figure from an international database unless the national agency itself allows it: national agencies calculate the factor from their system's actual generation mix, which can differ substantially from a regional average.
Argentina and Brazil: a brief note
This guide focuses on the four countries where we could verify figures directly against primary sources. In Argentina, the reference agency for the grid emission factor (the Argentine Interconnection System, SADI) is the Secretaría de Energía, within the wider framework our guide to environmental and sustainability regulation in Argentina describes; if your company already reports there, that same guide usually covers where to declare electricity consumption. In Brazil, the operator of the National Interconnected System (ONS) and the Ministry of Science, Technology and Innovation periodically publish the Brazilian grid's average emission factor. We haven't included figures for either country in this guide because they fall outside the verified scope of this piece.
Comparative summary
| Country | Agency | Corporate inventory factor |
|---|---|---|
| Colombia | UPME | 0.220 tCO2eq/MWh (2024, Resolution 000085 of 2026) |
| Mexico | CRE / SEMARNAT | 0.444 tCO2e/MWh (2024, in force for the 2026 COA report until the 2025 figure is published) |
| Chile | Ministry of Energy | Check the environmental indicators page directly; not verified in this guide |
| Peru | MINEM | Check the national emission factors document directly; not verified in this guide |
Common mistakes
- Using Colombia's CDM factor for a corporate inventory. Only the item B factor in Resolution 000085 of 2026 (0.220 tCO2eq/MWh) applies to GHG inventories.
- Using the wrong year of Mexico's factor. For the 2026 COA report, the current notice says to use the 2024 factor, not a 2025 value that doesn't exist yet.
- Copying a factor from an article or blog with no date or source. Factors change every year; a figure without the resolution or notice behind it can't be verified or defended to an auditor.
- Applying the same factor across every country a regional group operates in. Every grid mix is different; a company with sites across the region needs each country's own factor, not a Latin American average.
- Mixing the consumption factor with the project factor. Colombia makes this explicit with two separate categories, but the same distinction, electricity consumption versus a project's certified reduction, applies conceptually in the other countries too, even where it isn't as clearly documented.
Frequently asked questions
What's the current electricity emission factor for corporate inventories in Colombia?
0.220 tonnes of CO2 equivalent per MWh, for the year 2024, set by UPME Resolution 000085 of 2026, dated 23 February 2026.
Which factor should a Mexican company use for the 2026 COA report?
The 2024 factor (0.444 tCO2e/MWh), per SEMARNAT's notice of 29 May 2026, while the 2025 factor remains in process at the Ministry of Energy.
Why does Colombia have four different factors instead of one?
Because they measure different things: one is for greenhouse gas inventories (0.220 tCO2eq/MWh) and the other three are for calculating certified reductions from Clean Development Mechanism projects, depending on the project type and accreditation period.
Where is Chile's electricity emission factor published?
The Ministry of Energy publishes it in its climate change environmental indicators section; we recommend checking that page directly, since this guide couldn't verify a current numeric value at the time of writing.
Which agency publishes Peru's electricity emission factor?
The Ministry of Energy and Mines (MINEM), in a specific document of national emission factors for electricity consumption, distinct from the Infocarbono system the Ministry of the Environment runs for the national inventory.
Can I use a generic international electricity emission factor if my country hasn't published its own?
Only if the national agency explicitly allows it. The most defensible approach under audit is to use the most recent officially published national factor, documenting which year and source it comes from.
Tracking down the right factor for each country, each year and each purpose is exactly the kind of scattered data point that complicates a multi-country scope 2 inventory. Our carbon footprint solution centralises these factors and keeps them current alongside the rest of the inventory.
