An analysis of the DST changes by the American Council for an Energy Efficient Economy (ACEEE) found that by 2020, the amendment would cumulatively save consumers $4.4 billion in energy costs, while helping to avoid the construction of three medium-sized, coal-fired, 330-megawatt electric power plants, according to Markey's office.

The DST changes will also mean that Americans will save an estimated 279 billion cubic feet of natural gas and cut nearly 10.8 million metric tons of carbon emissions that many scientists say contribute to global warming, according to the study. The energy savings occur because people use less electricity at night if it's still light outside, according to Markey's office.