A statement about "baseload power" by Energy Secretary Rick Perry in April frames a debate about the future of the U.S. electricity grid under President Trump.
Perry asked his staff to send him a report by the end of this week on the health of the nation’s high-voltage electricity grid. His memo targeted wind and solar power as suspected threats to grid reliability.
Boosted by "extremist political agendas," according to Perry, renewable energy undermines baseload power that includes large coal and gas-fired generators, dams, and nuclear reactors. "Baseload power is necessary to a well-functioning electric grid," Perry declared in the memo.
But studies of power grid reliability suggest the greatest risks aren’t from the gradual loss of coal and nuclear generation, or from too many solar panels. Rather, grid operators and electricity companies struggle with inconsistent federal and state policies developed in a deeply divided political environment. Today, that is what’s buffeting a rapidly evolving 21st-century grid that, in reality, relies on natural gas instead of coal and is integrating increasing volumes of wind, solar and clean technology.
Will Perry’s short-order grid report harness agency policy to support Trump’s goal of reviving a coal-based electric grid? Or will it address trends — that appear irreversible to many in the industry — supporting a multidimensional grid?
"There is a distinction between the political connotation of baseload and the industry’s definitions," said Devin Hartman, senior fellow at the R Street Institute.
Providing "baseload" doesn’t make the grid more secure. "It just refers to a power plant that operates at a steady rate of output over an extended period of time."
"The grid, as it evolves, is a work in progress," said Brattle Group energy economist Judy Chang. "There is no evidence it is less reliable."
A newly issued report by the North American Electric Reliability Corp. (NERC), the bulk power network’s security monitor, found that overall benchmarks of reliability were stronger in 2016, a year when the growth of natural gas and renewable generation soared.
"Even the more challenging days in the year demonstrated better resilience than in prior years," NERC said in its "State of Reliability 2017."
There are plenty of worries ahead, NERC acknowledged, including growing dependence on gas, with the need for more long-haul pipeline capacity.
Progress or regress?
The recommendations that will go to Perry have been closely held by a drafting team directed by DOE political appointee Travis Fisher, with consultant Alison Silverstein as the principal author. Silverstein is a widely experienced energy analyst who was a senior adviser to a Republican chairman of the Federal Energy Regulatory Commission under President George W. Bush, and she currently heads one of the major initiatives coming out of President Obama’s 2009 smart grid funding.
Some industry experts speculate that the report will propose federal support intended to hold coal generation at its current 30 percent share of total U.S. electric power production.
It might also recommend a faster phaseout of federal tax support for wind and solar power in line with Trump’s rejection of Obama’s clean energy goals.
But the headline after DOE releases its report could be: "In which century is Perry’s electric grid operating?"
Lying beneath a politicized argument about coal versus natural gas versus renewables is a real-world issue that will become more troubling as the grid replaces old coal plants and nuclear reactors.
That is the need for a vital, esoteric set of what’s called "essential reliability services." Grid operators need these services to keep voltages and frequencies stable and within precise limits and to ensure rapid responses by generators when power demand suddenly shifts up or down. The NERC report noted "a growing concern that the existing markets do not accurately reflect products necessary to support the new resources being integrated today," the report said.
"We ran the grid for a hundred years and didn’t differentiate between energy and other services" such as frequency support or fast ramp-up of new supply, said Arshad Mansoor, senior vice president of the research and development group for the Electric Power Research Institute. Grid operators no longer have that luxury, he said.
A report by PJM Interconnection, the grid operator in the Mid-Atlantic and eastern Great Lakes region, in March concluded that despite challenges, "PJM could maintain reliability with unprecedented levels of wind and solar resources, assuming a portfolio of other resources that provides a sufficient amount of reliability services" — the same set of voltage, frequency and response supports that NERC cited.
Grid support was taken for granted into the 1990s because operators of big coal-fired plants and nuclear reactors usually provided them as a matter of course, noted Susan Tierney, managing principal of the Analysis Group.
The momentum of a heavy, rotating generator in a coal plant was a ready cushion to dampen the immediate shock of a big power line unexpectedly shorting out. A large, 24/7 coal plant near an urban area was a ready source of "reactive" power, the short-range energy that supports stable voltages and helps prevent cascading blackouts.
"If you get more renewables on the system, you’re going to have a deficit in some of those essential reliability services," Hartman said, unless grid planners, operators and regulators act to provide them.
A new generation of gas-fired plants and wind farms can also provide support services. So can advanced power electronics. But their ready availability when and where they are needed can’t be taken for granted. Regulations or market rules will have to be changed to ensure their presence, grid officials say.
"We are very, very cautiously watching the change in the resource mix," said NERC Vice President James Merlo. "I don’t want to say it’s more difficult. It’s different."
In one example, concentrated pockets of solar power can be a challenge in bringing the grid back up after a widespread outage, said John Moura, NERC’s director of reliability assessment and system analysis.
Restoration requires smaller diesel generators that can restart on their own, then bring capacity up gradually, always keeping the electricity supply in synch with the demand on the system.
The coal plant retirements and the growth of gas and renewable power in the past decade have not compromised the grid’s black-start capacity, Moura said.
Bringing back up a part of a city with a lot of rooftop solar power would be a new headache for operators, he said, since those units will all try to come back on at the same time, he said.
"I’m not blaming solar," he said. "It’s another change in the grid that has to be planned for."