Hulking nuclear plants try to get nimble in volatile power markets

New York

NUCLEAR reactors, the lumbering giants of electricity generation, are trying to become more agile. Power grids have become so swamped with volatile wind and solar that traditional plants are being forced to abruptly adjust their own output to keep systems stable - or pay a penalty.

That's prompting reactor owners including Exelon Corp and Duke Energy Corp to develop ways to tap the brakes on massive plants built to run non-stop. The future of nuclear power may hinge on the effort.

Reactors, which some environmentalists see as key in the fight against global warming, are already struggling to be profitable as cheap natural gas pulls down power prices. And the challenge of ramping up and down to keep pace with wind and solar will only get worse as California and other states push to eliminate fossil fuels.

"We're going to see this problem more and more," said Matt Crozat, senior director of policy development at the Nuclear Energy Institute. "These trends won't abate."

Exelon, the biggest US nuclear operator, is already tinkering to make plants more nimble, including by adjusting control rods inserted into the core of a reactor to absorb neutrons and slow chain reactions.

That and other measures can help reduce power by almost 15 per cent in less than an hour, said Lacey Dean, a spokeswoman.

Exelon regularly adjusts output at its Quad Cities and Byron plants in Illinois when they face negative pricing, which means the grid is so awash in power that generators must either cut output - or pay to keep sending electricity to the system.

There have been 37 hours of negative pricing this year in the market Byron serves, thanks largely to wind power flooding in from Iowa, according to Adam Jordan, director of power analytics at Genscape Inc. That dragged prices per megawatt hour as low as -US$92.81 on Feb 12.

While nuclear plants depend largely on long-term contracts, they are still affected by real-time prices, said William Hogan, a professor at the John F Kennedy School of Government at Harvard University and research director at the Harvard Electricity Policy Group.

When spot prices are lower than their operating costs, it's cheaper for operators to purchase and resell electricity than produce it themselves - if they have flexibility to quickly cut output. "If you're running a plant that's on average profitable and sometimes not, it would be good to be able to adjust the output for the times when it's not," Prof Hogan said.

The challenge posed by wind and solar will only get worse for the nuclear industry. Generators on the grid that are operated by PJM Interconnection LLC will need to more than triple the amount of wind on the system in the next decade to meet states' clean energy goals.

Time is critical for nuclear plants, which supply about 20 per cent of electricity in the US. Reactors are struggling to stay solvent as the fracking boom has made gas cheap and abundant, pushing down wholesale electricity prices. BLOOMBERG