Comparing Q2 2023 to Q2 2022

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 715 lb CO₂ per MWh in the second quarter of 2023, which was down 7 percent from the same time frame in 2022.

Comparing performance in 2023 to 2005

The Power Sector Carbon Index for Q2 of 2023 was 46% lower than in the annual value in 2005, from 1,321 lb CO₂ per MWh to 715 lb CO₂ per MWh (or 599 to 324 g CO₂ per kWh). As of Q2 of 2023, the rolling annual average carbon intensity was 774 lb CO₂ per MWh (or 351 g CO₂ per kWh), which is 41% lower than the annual value in 2005. Total annual rolling CO₂ emissions were 1,484 million metric tonnes, which was 39% lower than in 2005.

Highlights of the 2023 Q2 results

• Total generation was down 3% in 2023 Q2 (1006 million MWh) when compared to 2022 Q2 (1043 million MWh).
• Coal generation was down 26% in 2023 Q2 (141 million MWh) when compared to 2022 Q2 (191 million MWh). Coal represented 14% of total generation in 2023 Q2
• Natural Gas generation was up 8% in 2023 Q2 (420 million MWh) when compared to 2022 Q2 (389 million MWh). Natural Gas represented 42% of total generation in 2023 Q2
• Hydro generation was down 6% in 2023 Q2 (65 million MWh) when compared to 2022 Q2 (69 million MWh). Hydro represented 7% of total generation in 2023 Q2
• Wind generation was down 15% in 2023 Q2 (102 million MWh) when compared to 2022 Q2 (121 million MWh). Wind represented 10% of total generation in 2023 Q2
• Solar generation was up 16% in 2023 Q2 (72 million MWh) when compared to 2022 Q2 (62 million MWh). Solar represented 7% of total generation in 2023 Q2
• Nuclear generation was down 1% in 2023 Q2 (183 million MWh) when compared to 2022 Q2 (184 million MWh). Nuclear represented 18% of total generation in 2023 Q2
• Other generation was down 22% in 2023 Q2 (7 million MWh) when compared to 2022 Q2 (9 million MWh). Other represented 1% of total generation in 2023 Q2
• Other Renewables generation was down 10% in 2023 Q2 (16 million MWh) when compared to 2022 Q2 (17 million MWh). Other Renewables represented 2% of total generation in 2023 Q2