Comparing Q4 2021 to Q4 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 772 lb CO₂ per MWh in the fourth quarter of 2021, which was down 5 percent from the same time frame in 2020.

Comparing performance in 2021 to 2005

The Power Sector Carbon Index for Q4 of 2021 was 42% lower than in the annual value in 2005, from 1,321 lb CO₂ per MWh to 772 lb CO₂ per MWh (or 599 to 350 g CO₂ per kWh). As of Q4 of 2021, the rolling annual average carbon intensity was 838 lb CO₂ per MWh (or 380 g CO₂ per kWh), which is 37% lower than the annual value in 2005. Total annual rolling CO₂ emissions were 1,583 million metric tonnes, which was 35% lower than in 2005.

Highlights of the 2021 Q4 results

• Total generation was up 2% in 2021 Q4 (984 million MWh) when compared to 2020 Q4 (967 million MWh).
• Coal generation was down 10% in 2021 Q4 (180 million MWh) when compared to 2020 Q4 (200 million MWh). Coal represented 18% of total generation in 2021 Q4
• Natural Gas generation was up 3% in 2021 Q4 (381 million MWh) when compared to 2020 Q4 (369 million MWh). Natural Gas represented 39% of total generation in 2021 Q4
• Hydro generation was up 5% in 2021 Q4 (64 million MWh) when compared to 2020 Q4 (61 million MWh). Hydro represented 7% of total generation in 2021 Q4
• Wind generation was up 16% in 2021 Q4 (109 million MWh) when compared to 2020 Q4 (94 million MWh). Wind represented 11% of total generation in 2021 Q4
• Solar generation was up 27% in 2021 Q4 (33 million MWh) when compared to 2020 Q4 (26 million MWh). Solar represented 3% of total generation in 2021 Q4
• Nuclear generation was flat in 2021 Q4 (190 million MWh) when compared to 2020 Q4 (191 million MWh). Nuclear represented 19% of total generation in 2021 Q4
• Other generation was down 4% in 2021 Q4 (9 million MWh) when compared to 2020 Q4 (9 million MWh). Other represented 1% of total generation in 2021 Q4
• Other Renewables generation was up 1% in 2021 Q4 (18 million MWh) when compared to 2020 Q4 (18 million MWh). Other Renewables represented 2% of total generation in 2021 Q4