For decades, hydroelectric and wood biomass were the largest sources of renewable energy in the United States. In recent years, other sources, such as wind and solar, have increased significantly. Watch this video to see how things have changed. And below, see your public power utility’s timeline of conservation and energy-efficiency efforts and initiatives, which began in the 1970s.




LES has a long history of using innovation to meet our customers’ needs while balancing high standards of reliability and cost effectiveness with sustainability. We started promoting conservation and energy efficiency back in the early 1970s, and we’ve continued to provide programs and partnerships to empower customers to become smart energy consumers. This focus on sustainability is visible throughout LES, from our power resource mix to our wide array of customer programs.


As we look to the future and the pursuit of LES’ decarbonization goal — achieving net-zero CO2 emissions from our generation portfolio by 2040 — that culture of sustainability and a balanced approach will be key to ensuring LES remains a valued partner and a source of support for our customer-owners.


LES timeline


LES green timeline

Portfolio CO2 rate (metric tons/net MWh)


Portfolio CO2 rate graph



As a public power utility, we continually strive to make decisions that align with the values of those we serve while positioning the utility for future success. Learn more about LES’ sustainability efforts at


Source: U.S. Energy Information Administration