Dive Brief:

• Generators around the country may have had their strongest year ever for generation efficiency, reaching a capacity factor of almost 92%, according to preliminary estimates released by the Nuclear Energy Institute, Smart Grid News reports. 
• NEI said actual nuclear power production was the 5th highest ever, coming in at an estimated 797.9 billion kWh. The industry’s record high electricity generation was 806.9 billion kWh, five years before, though there were more facilities operating in 2010 than there are today.
• The industry's increasing efficiency was highlighted by the closure of Vermont Yankee in 2014. Despite operating with one less nuclear facility last year, 2015 generation exceeded 2014, and observers say that efficiency could be a boon to helping meet federal emission standards.

Dive Insight:

Final data will not be available for another couple of months, but the nuclear industry believes capacity factors around the country may have set a record last year at 91.95% – possibly topping 2007’s efficiency rating by a single tenth of a percent

“The 2015 data confirm yet again what a tremendous asset nuclear energy technology is,” NEI Chief Nuclear Officer Anthony Pietrangelo said in a statement. “U.S. nuclear power plants continue to operate at exceptional levels of safety and reliability, while generating affordable electricity that consumers and our economy rely on."

NEI noted that power generated last year came from 99 plants in 30 states, down by one after the closure of Vermont Yankee in 2014. But despite that, the United States generated more nuclear power in 2015. "This record efficiency is even more important as states strive to meet new carbon-reduction targets for the electric sector," the group said.

Since the 1990s, nuclear generators each year have produced about one-fifth of America’s electricity supplies, even as total electricity demand has increased and nuclear power plants remained at roughly 10% of the nation’s installed electric generating capacity.

Nuclear generation peaked in 2010, when there were 104 reactors operating. In that year, the U.S. industry produced 806.9 billion kWh with an industry average capacity factor of 90.9%.

But the outlook for nuclear remains hazy even as the fleet continues to operate efficiently. Last year, an analysis of three rating companies said 11% of the U.S. nuclear generation fleet is at risk for early retirement, possibly putting emissions goals under the Clean Power Plan at risk.