Comparing Q3 2021 to Q3 2020

The Carnegie Mellon Power Sector Carbon Index provides a comprehensive picture of the carbon intensity of electricity production in the during the previous 12 months and over an extended period to 2001. The CMU index also provides a summary of how much electricity generation is from coal, natural gas, nuclear, and renewables. According to the Carnegie Mellon Power Sector Carbon Index, U.S. power plant emissions averaged 922 lb CO₂ per MWh in the third quarter of 2021, which was up 2 percent from the same time frame in 2020.

Comparing performance in 2021 to 2005

The Power Sector Carbon Index for Q3 of 2021 was 30% lower than in the annual value in 2005, from 1,321 lb CO₂ per MWh to 922 lb CO₂ per MWh (or 599 to 418 g CO₂ per kWh). As of Q3 of 2021, the rolling annual average carbon intensity was 848 lb CO₂ per MWh (or 385 g CO₂ per kWh), which is 36% lower than the annual value in 2005. Total annual rolling CO₂ emissions were 1,596 million metric tonnes, which was 34% lower than in 2005.

Highlights of the 2021 Q3 results

• Total generation was up 2% in 2021 Q3 (1180 million MWh) when compared to 2020 Q3 (1153 million MWh).
• Coal generation was up 13% in 2021 Q3 (282 million MWh) when compared to 2020 Q3 (249 million MWh). Coal represented 24% of total generation in 2021 Q3
• Natural Gas generation was down 3% in 2021 Q3 (480 million MWh) when compared to 2020 Q3 (496 million MWh). Natural Gas represented 41% of total generation in 2021 Q3
• Hydro generation was down 11% in 2021 Q3 (61 million MWh) when compared to 2020 Q3 (69 million MWh). Hydro represented 5% of total generation in 2021 Q3
• Wind generation was up 11% in 2021 Q3 (77 million MWh) when compared to 2020 Q3 (69 million MWh). Wind represented 7% of total generation in 2021 Q3
• Solar generation was up 23% in 2021 Q3 (49 million MWh) when compared to 2020 Q3 (40 million MWh). Solar represented 4% of total generation in 2021 Q3
• Nuclear generation was down 1% in 2021 Q3 (203 million MWh) when compared to 2020 Q3 (204 million MWh). Nuclear represented 17% of total generation in 2021 Q3
• Other generation was up 1% in 2021 Q3 (9 million MWh) when compared to 2020 Q3 (9 million MWh). Other represented 1% of total generation in 2021 Q3
• Other Renewables generation was up 4% in 2021 Q3 (18 million MWh) when compared to 2020 Q3 (18 million MWh). Other Renewables represented 2% of total generation in 2021 Q3