COLUMBUS — Coal has quickly slipped as Ohio's dominant source of electricity.

In just a dozen years, coal has gone from powering 87 percent of the state's homes, stores, offices and factories to 47 percent last year, according to the Public Utilities Commission of Ohio. The use of coal in fueling electricity fell 11 percentage points from just 2017 to 2018 even as President Donald Trump has vowed to revive the coal industry.

It is a similar story elsewhere around the country, especially in the Midwest and East, where several coal-fired power plants have shut down in the past several years. Coal is falling victim primarily to cheap, abundant supplies of natural gas, some of it sourced in the Utica and Marcellus shales in eastern Ohio, West Virginia and Pennsylvania.

Columbus-based American Electric Power, one of the nation's largest power companies and once heavily dependent on coal, has slashed its carbon dioxide emissions 59 percent since 2000 with a goal of an 80 percent reduction by 2050 as the company moves away from coal to natural gas and renewable sources such as wind and solar.

"Coal was by far the dominant source of the resources in this part of the country," said Nick Akins, the company's chairman, president and CEO.

Now with the revolution of shale along with the regulations on emissions of power plants, it is harder to make the case for coal, he said.

A new coal-fired power plant could take seven years to build and cost $5 billion. Simply upgrading an existing coal plant to meet environmental standards might cost $1 billion, Akins said. By contrast, a natural-gas power plant that produces the same amount of electricity might cost $1 billion to $1.3 billion and take two years to complete, he said.

"It [a coal plant] is a large capital investment, maybe a 60- to 80-year investment. Where technology is moving today, it is a tough bet to make," Akins said.

Natural gas, at one time a little-used source for electricity in Ohio, generated 34 percent of the state's power last year, up 10 percentage points in just a year.

Renewables, while growing, make up just 3 percent. The state's two nuclear plants provide about 15 percent of the state's power.

Nationally, natural gas has surpassed coal as the top source of power, fueling 35.1 percent of the electricity last year. Meanwhile coal has fallen to second place at 27.4 percent and is expected to decline to 22 percent in 2020.

Despite coal's recent slide, it is expected to be a significant source of power in the years to come in Ohio, according to a 2017 forecast by the PUCO.

That forecast shows the production of power in 2036 is expected to look much like it does today: 48.5 percent from coal, 36.9 percent from natural gas and petroleum, and 14.6 percent from nuclear and hydro.

The report provided no forecast for wind or solar, while noting that predicting power generation from those sources is difficult because of historically low usage in Ohio.

That outlook could change significantly in the next several years.

AEP is planning on closing its coal plant in Conesville in eastern Ohio next year. Akron-based FirstEnergy Solutions, the power-plant subsidiary of FirstEnergy, says it will shut down its Sammis coal plant along the Ohio River in 2022. Further complicating forecasts is the announcement by FES that it will close its two Ohio nuclear plants unless the state provides financial support to make them more competitive.

Ohio House Republican leaders have introduced a bill that would shore up the state's nuclear power plants by phasing in a monthly fee on electric bills that would rise to $2.50 a month for residential customers and $20 a month for commercial customers in 2021. The proposal also would eliminate other fees consumers pay for such things as energy efficiency and renewable energy.

The fees eventually would raise $300 million a year that would go to efforts to reduce the state's carbon-dioxide emissions. Because the nuclear plants produce about 90 percent of the state's emission-free electricity, most of the money would go to them.

Meanwhile, though, the number of gas-fired plants continues to grow in the state as do the pipelines from the Marcellus and Utica regions.

Four gas-fired plants have become operational in the past two years and six more have gotten approval or started construction, according to the PUCO.

During this winter's cold snap, however, it was the coal and nuclear plants in the region that turned out to be the most reliable sources for power, said Mike Cope, president of the Ohio Coal Association. While natural gas prices are low now, that hasn't always been the case and that could cost consumers, he said.

When a coal-fired power plant or a nuclear plant is shut down, that power source is likely lost for good, Cope said.

Paul Harden, chief operating officer of FirstEnergy Nuclear Operating Company, the operating subsidiary of the plants, said, "Our nuclear plants contribute to the fuel diversity and fuel security of the regional grid and are able to withstand natural disasters and terrorist attacks."