Question 1

How much CO₂ does a solar panel system offset?

Accepted Answer

A typical 6 kW residential solar system offsets 4-8 metric tons of CO₂ per year, depending on location and grid emission factor. In the US (386 g CO₂/kWh average), a 6 kW system producing 9,000 kWh/year offsets approximately 3.5 metric tons of CO₂ annually — equivalent to planting about 130 trees each year. Use the PVSize Carbon Offset Calculator for a personalized estimate.

Question 2

How is carbon offset calculated for solar panels?

Accepted Answer

Carbon offset is calculated as: System Size (kW) × Annual Production (kWh/kW) × Grid Emission Factor (kg CO₂/kWh). The grid emission factor varies by region — US average is 386 g/kWh, California is 210 g/kWh, Texas is 590 g/kWh, and the EU average is 230 g/kWh. This represents the CO₂ that would have been emitted by the grid to produce the same electricity your solar system generates.

Question 3

How many trees is my solar system equivalent to?

Accepted Answer

Tree equivalence is an illustrative comparison, not a formal carbon accounting standard. PVSize shows an approximate tree-equivalent figure so users can understand scale, but the exact number depends on the comparison method and the grid emission factor used.

Question 4

Which grid emission factor should I use?

Accepted Answer

Use the emission factor for your local grid region from eGRID (EPA) or your national energy authority. US average: 386 g CO₂/kWh; California: 210 g/kWh (cleaner grid with natural gas and renewables); Texas: 590 g/kWh (coal and gas heavy); EU average: 230 g/kWh; France: 60 g/kWh (nuclear dominant); China average: 430 g/kWh. Higher emission factors mean your solar system offsets more carbon.

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