Just a decade ago, half of the electricity Americans consumed was produced by burning coal. Natural gas, which burns cleaner than coal and emits about half as many greenhouse gases, was responsible for less than 19 percent of U.S. power generation. Policymakers worried the country was facing a natural gas supply crunch and encouraged the construction of facilities to import liquefied natural gas from abroad.

Then came the revolutionary integration of technologies such as hydraulic fracturing and horizontal drilling. Together, they unlocked abundant new supplies of natural gas from places like the Marcellus Shale. New data show these additional supplies have helped significantly alter the nation’s energy mix in a relatively short time.

According to the U.S. Energy Information Administration, natural gas power generation exceeded power generation from coal in April. More than 92,500 Gigawatt-hours of electricity were produced from natural gas, or 31 percent of the country’s electric-power generation. That surpasses the nearly 89,000 GWh from coal, which accounted for 30 percent of the electricity lighting and powering Americans’ homes and businesses.

The Energy Information Administration cites a number of factors that have contributed to this shift away from coal’s predominance in power generation, including new environmental regulations. But the biggest factor making any shift possible is the abundance and affordability of natural gas coming from the country’s shale fields.

This development is particularly noteworthy because it’s the first month ever that more electricity was generated from natural gas than from coal. In fact, as recently as 2010, natural gas accounted for just 22 percent of U.S. electricity production, compared to 44 percent for coal.

As a result of the growing role played by natural gas in generating electricity, our air is getting cleaner and the country has lowered greenhouse gas emissions to levels not seen in two decades. And our abundant supplies of natural gas are positioning the U.S. to be able to export natural gas – quite a turnaround from recent plans to boost imports.