Solar Panels Carbon Footprint & Environmental Impact

Carbon Footprint

Square Footprint

Smoke Stack 400
Clouds 400

25.8 kg CO2e / MWh

(United States Average)

5.8 ft2 Land Use Change / MWh

(United States
Average)

Carbon Footprint

Square Footprint

Smoke Stack 800
Clouds 800

25.8 kg CO2e / MWh

(United States Average)

5.8 ft2 Land Use Change / MWh

(United States Average)

If the average US home's annual electricity (10.715 MWh) was powered by US solar power, it would use:

32.5

Gallons of Gasoline Equivalent

276.5

kg CO2e
If the average US home's annual electricity (10.715 MWh) was powered by US solar power, it would use:

32.5

Gallons of Gasoline Equivalent

276.5

kg CO2e

The Carbon Footprint of US solar panels is 25.8 kg CO2e per Megawatt Hour (MWh). The greenhouse gas emissions of solar panels are 18.8 times lower than natural gas.

If the average US home's annual electricity (10.715 MWh) was powered by US solar power for 10 years, it would result in land use change equivalent to:

4.3

Parking Spaces Equivalent

621

ft2
Parking Spaces 800
If the average US home's annual electricity (10.715 MWh) was powered by US solar power for 10 years, it would result in a land use change equivalent to:

4.3

Parking Spaces Equivalent

621

ft2

Over the 25 year lifespan of a ground-mounted solar power plant, the land use change resulting from solar power is 5.8 ft2 Megawatt Hour. If the same land was used for 100 years, the land use change would be 1.5 ft2 Megawatt Hour. The land use change resulting from US solar panels is 1.5 times lower than natural gas.

Data and Assumptions

Carbon Footprint:

  • Lifecycle Carbon Footprint of Solar Power is based on the harmonized value of 25 g CO2e / kWh for monocrystalline solar PV reported by Louwen et al. (2016). Original value is based on Wetzel & Borchers (2015).
    • Solar radiation value of 1,646 kWh m2 / yr is based on the Global Solar Atlas (2022) Global Horizontal Irradiation average for the lower 48 US states. Average raster file value was obtained using QGIS (2022). Note this value is likely an underestimation of installed solar capacity, as solar is more likely to be installed in areas with higher solar radiation.
    • Value adjusted to 25.8 g CO2e / kWh to adjust for 1,700 kWh / m2 / yr solar radiation reference value used in Wetzel & Borchers (2015), which is 1.033 times higher than this estimate.
    • Monocrystalline solar is assumed for the carbon footprint of solar panels, as monocrystalline panels comprised nearly 90% of all PV sales in 2020 (Laser Focus World, 2020).
  • Lifecycle Carbon Footprint of Natural Gas based on NREL (2022A). Median value of 486 g CO2e / kWh is based on a harmonized value from 58 studies with 93 unique values.
 
 

Land Use:

  • Square Footprint of Solar Power is based on Van de Ven et al. (2021). Standard assumptions from Van de Ven et al. (2021) are used for this calculation. The full model is available in a calculator on the Solar Land Use Page
    • Solar radiation value of 1,646 kWh m2 / yr is based on the Global Solar Atlas (2022) Global Horizontal Irradiation average for the lower 48 US states. Average raster file value was obtained using QGIS (2022). Note this value is likely an underestimation of installed solar capacity, as solar is more likely to be installed in areas with higher solar radiation.
    • Land use is based on the geographic center of the Contiguous United States at 39.5 degrees of latitude (GeoHack, 2022).
    • Based on these assumptions, the land use of Solar Power is 145.3 ft2 / MWh (13.5 m2 / MWh) over the estimated 25 year lifespan (NREL, 2022B) of a ground-mounted solar power plant. Note that land use varies substantially by latitude and by solar radiation. The value presented is representative of the United States average solar generation.
    • Land use per MWh for 1 year is divided by the expected 25 year lifespan, which results in 5.8 ft2 / MWh (0.54 m2 / MWh).
    • The value presented is representative only of the lifespan of 1 power plant, which is a conservative assumption, as it would be expected that a solar power plant would be replaced at the end of life and the land would be re-used. If, for example, one assumed a 100 year lifespan, which would result in 4 replacements of the solar power plant on the same parcel of land, the resulting land use change would drop from 5.8 ft2 / MWh (0.54 m2 / MWh) to 1.5 ft2 / MWh (0.14 m2 / MWh).
  • Square Footprint of Natural Gas based on Trainor et al. (2016). The combined land use factor for all natural gas production methods is 0.79 km2 / TWh (0.79 m2 / MWh), which equals 8.5 ft2 / MWh. As natural gas is an extractive resource, land use change occurs every year, and thus power plant lifespan does not affect land use change. Land use change varies by the method of natural gas extraction. See the Natural Gas Power Carbon Footprint & Environmental Impact page for the assumptions made.
  • Square Footprint of a Parking Space is 144 ft2, based on the average dimensions stated by Franklin Street (2019).
 
General Assumptions:
  • Average 2020 US Household annual electricity of 10,715 kWh is based on EIA (2021A).
  • Carbon Footprint of gasoline is 8.50 kg CO2e / gallon, based on EIA (2021B).

References

Colville, F. (November, 2020). Monocrystalline cells dominate solar photovoltaic industry, but technology roadmap is far from certain. LaserFocusWorld. See Link to Source

EIA: US Energy Information Administration. (2021A). How Much Electricity Does an American Home Use?. See Link to Source

EIA: US Energy Information Administration. (November 18, 2021B). Carbon Dioxide Emissions Coefficients by Fuel. See Link to Source

Franklin Street. (May 23, 2019). How Large is a Parking Space? See Link to Source

GeoHack. (2022). Geographic Center of the Contiguous United States. See Link to Source

Global Solar Atlas. (2022). China Global Horizontal Irradiation. See Link to Source

Louwen, A., Van Sark, W. G., Faaij, A. P., & Schropp, R. E. (2016). Re-assessment of net energy production and greenhouse gas emissions avoidance after 40 years of photovoltaics development. Nature Communications, 7(1), 1-9.

NREL: National Renewable Energy Laboratory. (2022A). Life Cycle Assessment Harmonization. See Link to Source

NREL: NREL: National Renewable Energy Laboratory. (2022B). Useful Life. See Link to Source

QGIS.org, 2022. QGIS Geographic Information System. QGIS Association. http://www.qgis.org

Trainor, A. M., McDonald, R. I., & Fargione, J. (2016). Energy sprawl is the largest driver of land use change in United States. PloS one, 11(9), e0162269.
 
Van de Ven, D. J., Capellan-Peréz, I., Arto, I., Cazcarro, I., de Castro, C., Patel, P., & Gonzalez-Eguino, M. (2021). The potential land requirements and related land use change emissions of solar energy. Scientific reports, 11(1), 1-12.
 
Wetzel, T., & Borchers, S. (2015). Update of energy payback time and greenhouse gas emission data for crystalline silicon photovoltaic modules. Progress in Photovoltaics: Research and Applications, 23(10), 1429-1435.