Home(The Small) Solar and Wind Energy Carbon Footprints
(The Small) Solar and Wind Energy Carbon Footprints
Solar and Wind Energy CO2 Footprints
The carbon footprints of solar and wind are small, and are even tinier when compared to the carbon footprint of fossil fuel energy sources.
Solar and wind DO have carbon footprints. However, that must be quantified and compared to fossil fuel options, which have significantly higher carbon footprints. An important term here is the ‘carbon debt’ period – during which solar and wind produce carbon emissions (in the materials, manufacturing, and transportation stages). The other important term is the ‘carbon payback’ period – during which solar and wind produce carbon emissions-free energy.
Carbon-free Energy
Solar and wind are carbon-free energy sources. Solar and wind energy production produce zero carbon emissions. Solar and wind generate 0 grams of CO2 per kWh during energy generation and are carbon neutral in 1-3 years (less than 1 year for most wind energy operations). Meanwhile, coal produces ~1000 grams CO2 emissions per kWh (less than 1/2 that for gas).
If solar and wind are carbon-free energy sources, what is their carbon footprint? Solar’s carbon footprint is ~50 grams of CO2 emissions per kWh (for solar energy eventually generated by the panel while the ‘carbon debt’ is paid off) produced during the mining, manufacturing, and transportation of solar vs. ~1000 grams of carbon emissions per kWh for burning coal (less than 1/2 that for gas).
Wind’s carbon footprint is lower than solar (so low, as seen in the chart by NREL below, that it is close to zero – but all the steel for the turbines does represent a carbon footprint – less of a CO2 footprint if low-carbon steel is used).
Where do the carbon footprints of solar and wind come from?
The carbon footprints of solar and wind are due to the carbon dioxide emissions generated from:
the mining of the rare earth metals and minerals used in the renewable energy (RE) technologies solar and wind
the production of the steel needed for the RE
the manufacturing of the RE
the transportation of the RE technologies and materials where they are finally assembled
There are ~50 grams CO2 emissions per kWh for solar panels for solar energy eventually generated by the panel while the ‘carbon debt’ is paid off. These emissions, generated during the ‘carbon debt’ period from the mining, manufacturing, and transportation of solar are relatively small.
There’s an even lower carbon footprint for wind (slightly lower – see the carbon footprint charts by Yale Climate and NREL below) vs ~1000 grams emissions per kWh for burning coal (less than 1/2 that for gas).
**Here are common energy sources (fossil fuel energy sources and solar) and the amount of CO2 that’s emitted in order to produce them (in GRAMS for SOLAR and in POUNDS for fossil fuel sources (based on different units of energy):
In the chart below are the estimated POUNDS of CO2 emissions per kWh for fossil fuel combustion – that is compared to the tiny amount of GRAMS of CO2 that are produced during the materials, manufacturing, and transportation phases of solar and wind. Once the energy generation stage begins for solar and wind, GHGs are reduced to virtually zero.
U.S. electricity net generation and resulting CO2 emissions by fuel in 2021
The solar carbon payback period is 1-3 years (with a lifespan of 20-30 years of carbon-free energy production).
The wind carbon payback is less than 1 year (with a lifespan of 20-25 years of carbon-free energy production)
Solar is responsible for about 20 (in the 10-30 range) times less CO2 emission from pre-energy production stages vs. coal at energy generation stage emissions
Wind is responsible for (those small CO2 grams per kWh numbers in the above chart from Yale Climate over the carbon payback period)
