As the economies of ASEAN countries have grown, making energy has become one of their biggest concerns. This research examines CO2 emissions from electricity production sources in ASEAN countries. The paper examined data from 1971 to 2020 using methodologies such as ordinary least squares (OLS), fixed-effects (FE), random effects (RE), generalized methods of moments (GMM), and quantile regression ... [Show full abstract] (QR). Here, the Housman test reveals that FE is better than RE. The Hansen and Sargan tests show that all instruments are valid. According to the FE, RE, and GMM approaches, electricity generated from coal and oil deteriorates the environment. The use of coal and natural gas results in higher CO2 emissions, according to the OLS and QR methods. All available evidence suggests that coal-fired power generation has a higher impact on emissions than any other source. There is a strong correlation between CO2 and coal at 0.514. While CO2 and hydro have the strongest negative correlation, this is − 0.530. All regression methods assure that hydroelectricity generation can reduce CO2 emissions more than any other energy source. A 1% rise in hydro power reduces CO2 emissions by 0.576% in FE and by 0.05% in differenced GMM estimation. On the other hand, a 1% rise in coal-generated electricity increases CO2 emissions by 0.158% in FE and 0.017% in the differenced GMM estimation. The study suggests that CO2 emissions can be reduced without significantly affecting electricity generation if fossil fuel consumption is reduced. The government should launch public and private initiatives to promote renewable energy sources such as wind, hydropower, and solar to counteract climate change.