Electricity Carbon Footprint Calculator
Calculate CO₂ emissions from electricity use and the savings from solar.
Please note: Estimates for planning only. Actual solar output depends on your latitude, roof orientation, shading, weather and equipment. Get a site-specific assessment and quotes before committing.
What the Electricity Carbon Footprint Calculator does
Electricity emissions are consumption multiplied by the grid carbon intensity where you live. That intensity varies by more than thirty times between a hydro-powered grid and a coal-heavy one, which is why the same appliance has wildly different climate impact in different countries.
Formula
Annual CO₂ = Annual kWh × Grid intensity ÷ 1,000CO₂ avoided = Solar generation × Grid intensity ÷ 1,000Net emissions = Annual CO₂ − CO₂ avoided
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Annual electricity use | kWh | Yes | Accepts more than 0. |
| Grid carbon intensity | one of 7 options | Yes | — |
| Annual solar generation | kWh | Optional | Accepts 0 or more. |
| Years to project | number | Yes | Accepts 1 or more, up to 40. |
How to use it
- Choose Grid carbon intensity.
- Enter Annual electricity use and Years to project.
- Optionally add Annual solar generation.
- Select Calculate.
Worked example
10,800 kWh a year on a 380 g/kWh grid with 7,884 kWh of solar.
- Usage
- 10800 kWh
- Intensity
- 380 g/kWh
- Solar
- 7884 kWh
4,104 kg without solar, 1,108 kg with — 2,996 kg avoided a year, about 143 trees or 24,966 km of driving.
Frequently asked questions
Why does grid intensity vary so much?
It reflects the generation mix. A grid running on hydro and nuclear emits under 50 g/kWh; one running on coal exceeds 800.
Do solar panels have a carbon cost?
Yes, from manufacturing. The energy payback is typically one to three years, after which the panels are effectively carbon-free for their remaining 20-plus years.