Ameren Missouri's latest report looking 20 years into the future predicts dramatic increases in the amount of electricity produced by wind and solar generation.
The Integrated Resource Plan is filed every three years with the Missouri Public Service Commission.
Ameren Missouri filed its newest report Monday, planning to have added at least 700 megawatts of wind generation by 2020, at an investment of around $1 billion.
That's enough to provide power for 200,000 homes, Environmental Communications Manager Brad Brown said.
Additionally, Ameren Missouri expects to add 100 megawatts of solar generation over the next decade, with 50 megawatts expected to be online by 2025.
"We constantly are monitoring and watching new technologies, and have been doing so for wind and solar energy over the last several years," said Ajay Arora, Ameren's vice president of environmental services and generation resource planning.
"Wind energy has made some pretty significant technological advancement, in terms of efficiency improvements and resulting cost-reductions."
Some wind farms have been developed in northwestern Missouri, with many others in Kansas, Nebraska and Iowa among the Midwestern states.
But the technological advancements make it possible to build more wind farms in Missouri, Arora said, and Ameren Missouri is looking for locations especially in the northern part and the southwestern part.
"We still need a wide space, but we can be more flexible in terms of the actual location," he said.
Some proposals, like the Grain Belt transmission lines across northeastern Missouri, have run into regulatory or citizen opposition. But, Arora said, those lines will be critical to the future of using renewable electricity.
Ameren Missouri already generates electricity from a solar panel "farm" in St. Charles County and is developing a facility at the St. Louis Lambert International Airport that should be done next year.
Arora said more studies are being done to find other solar farm locations in the state.
The report doesn't place a lot of emphasis on nuclear energy.
"We extended the operating license of the Callaway Nuclear Energy Center through 2044," he explained. "So, that's certainly beyond the planning horizon in this report. Callaway is a resource that will be with us for a long time.
"We're really excited about the advancements made in new, renewable energy, and we expect, over the foreseeable future, that will be the form of energy that allows us to maintain stable and predictable rates for our customers."
Missouri voters in 2008 approved an energy plan to increase the use of renewable energy sources.
Ameren Missouri's report said it already has significantly reduced emissions from 2005 levels, "including a 26 percent reduction in carbon emissions in 2016."
By 2030, the plan said Ameren Missouri is targeting a 35 percent carbon emissions reduction from 2005 levels, a 50 percent reduction by 2040 — and an 80 percent reduction by 2050.
Several years ago, the company announced it would stop using the coal-fired Meramec Energy Center in south St. Louis County by the end of 2022.
Meramec began operating in 1953, and is the oldest of the company's four coal-burning power plants.
(The Sioux plant, St. Charles County, began operating in 1967; the Labadie plant in Franklin County, 1970; and the Rush Island plant, Jefferson County, in 1976.)
"This plan announces the retirement of our coal-fired energy centers at the end of their useful life," Arora said. "We are really invested in making (coal-fired power) a lot more flexible such that it can ramp up and ramp down, and cycle lower — and that allows us to integrate a lot more wind and solar energy."