Carbon Offset Calculator
See how much CO2 your solar panels avoid every year — and what that means in trees, car miles, and gallons of gas.
Understanding Carbon Offsets from Solar
Emission Factors by Region
Every kWh of electricity you generate with solar displaces a kWh that would otherwise come from the grid, which is a mix of fossil fuels and renewables. The grid emission factor (kg CO2/kWh) reflects that mix. Coal-heavy grids like parts of Australia and Texas have higher factors, while California's cleaner grid has a lower factor — meaning each kWh of solar there avoids less CO2 in absolute terms.
Trees Planted Equivalent
A mature tree absorbs approximately 21 kg (48 lbs) of CO2 per year. This equivalency gives a tangible sense of scale but is an approximation — actual absorption rates vary by tree species, age, and climate.
Car Miles Offset
The average US passenger vehicle emits approximately 404 grams (0.404 kg) of CO2 per mile driven, based on an average fuel economy of about 28 MPG. Dividing your total CO2 offset by this factor gives the equivalent miles of driving avoided.
Gasoline Equivalent
Burning one gallon of gasoline releases approximately 8.89 kg of CO2 into the atmosphere. The gallons-saved figure represents the amount of gasoline that would have emitted the same CO2 as your solar offset.
Lifetime Impact
Solar panels are typically warrantied for 25 years and continue producing well beyond that. The 25-year figure shows your cumulative environmental contribution assuming consistent production — a significant legacy impact for a single household installation.