Renewables and distributed resources can help the U.S. significantly reduce greenhouse gas emissions by mid-century. But a big debate remains over the role of nuclear power in that transition, especially without the Clean Power Plan.
Hawaii intends to get to 100% renewables by 2045 without nuclear power. California, New York, and other states have targeted 50% renewables by 2050, with or without it. And a 100% renewables power mix without nuclear is possible for nearly every nation by 2050, according to Stanford professor Mark Jacobson's Solutions Project.
But renowned climatologist James Hansen, billionaire Bill Gates, and a roster of other voices say only an energy mix that includes nuclear power can beat climate change.
A new paper from Rhodium Group adds to the debate. The closure of the most vulnerable nuclear plants in the U.S. fleet will likely drive greenhouse gas emissions (GHGs) up in 2030, analysts found, despite a renewables boom.
“We took the best available information and came up with 24 GW that are identifiably at risk of closure because of economic factors between now and 2030,” Whitney Herndon, a Rhodium research analyst, told Utility Dive. “That is in addition to the recent batch of five plants already retired or scheduled for retirement.”
In the face of higher operating costs and lower electricity prices, the economic viability of the nation's nuclear fleet — supplier of 19% of U.S. electricity — is now increasingly in doubt. Older plants are being scheduled for retirement when operators say they could be authorized to run decades longer.
If that happens, the paper finds, greenhouse gas emissions will rise, particularly if the Trump administration throws out the Clean Power Plan, as expected. Nuclear advocates say keeping the vulnerable plants going is the only practical choice. California, as usual, has a different idea.
The nuclear situation after Trump
According to the U.S. Energy Information Administration, five nuclear facilities have been retired over the past five years: Nebraska’s Fort Calhoun, California’s San Onofre, Florida’s Crystal River, Wisconsin’s Kewaunee, and Vermont’s Yankee.
The plants represent an estimated 4.6 GW of shuttered generation that has been replaced largely with fossil fuel-generated electricity, Herndon said.
“We expect that to be the case for future retirements as well,” wrote the authors of the Rhodium report, “Nukes In The Crosshairs Revisited.”
“The exact impact depends on the fate of the Clean Power Plan (CPP) in court and the design of State Implementation Plans (SIPs) if the CPP is upheld,” it adds.
The Rhodium paper offers three scenarios, two with varying implementations of the CPP and one that assumes no CPP. The paper also assumes that, in any of the three scenarios, over 75% of the generation used to replace the 24 GW of capacity lost would be replaced mostly by power from natural gas combined cycle (NGCC) plants.
The Rhodium paper came ahead of the election of Donald Trump, making the first two scenarios less significant, Herndon said.
“It is likely there will be no Clean Power Plan in the Trump administration,” she said. “That means an increase of 50 million metric tons or more of emissions in 2030 due to nuclear retirements. This paper gives an analytical foundation for trying to keep the at-risk nuclear plants online.”
The Trump position on nuclear is not certain. Sen. Jeff Sessions (R-AL), the recently announced choice for Attorney General, is a long-time nuclear proponent. Many of the names so far bandied for Secretary of Energy, on the other hand, are not known to be supporters.
Some of Trump’s most detailed comments on nuclear energy date back to 2011, when he was interviewed on Fox News after the Tsunami-induced meltdown at Japan’s Fukushima Daiichi nuclear facility. In a rhetorical dance that’s now become familiar, Trump said that he was “very concerned” about the safety of nuclear energy after the disaster, particularly threats from terrorists and earthquakes. But he quickly dismissed those factors, saying he was “very strongly in favor of nuclear.”
“A plane goes down and people keep flying,” Trump said. “You get into an auto crash and people keep driving. There are problems in life. Not everything is so perfect. But you have to have the best people in terms of safeguards for nuclear energy.”
Closures could increase CO2
An at-risk plant is too expensive to run without upgrading and too expensive to upgrade, Herndon said.
Based on patterns established by closures to date, over 75% of the 24 GW of nuclear generation at would be replaced by natural gas if it retired, the report found. Renewables would replace coal generation and supply whatever is needed to meet new demand.
If the CPP were to be upheld but those nukes retired, “power sector emissions are 38 million tons higher in 2020, 22 million tons higher in 2025 and 6 million tons higher in 2030 than in a scenario where all at-risk nukes remain online,” Rhodium found.
In what is now the most likely scenario, the Trump administration would block the CPP by not defending it in court or issuing a new regulation rescinding it. In that case, power sector emissions would rise by 4 million tons relative to 2015 levels by 2020 and 96 million tons by 2030, Rhodium’s modeling shows.
“If at-risk nukes retire, power sector emissions remain at 2015 levels in 2020 and grow more than twice as fast between 2020 and 2030 than they would otherwise,” Herndon’s modeling found.
The future for nuclear plants may be less optimistic if there is not an effort from the Trump administration to make emissions reductions a policy goal, said Matt Crozat, senior director of business policy at the Nuclear Energy Institute. The only alternative would be policy incentives at the regional or state level.
If a state recognizes and values the “non-emitting characteristics of nuclear, he said, “there would be economic forces to keep those at-risk plants in place.”
New York is already moving that direction, approving financial supports for upstate nuclear plants to preserve the carbon-free generation earlier this year. And Illinois lawmakers could pass a bill this week that would save three nuclear plants there.
State actions, alternative strategies and Diablo Canyon
Going forward, policy on emissions will likely be predominantly at the state level, Crozat said. Whether those policy supports keep the at-risk plants online will be “on a case-by-case basis and tied in with other, larger forces,” he said.
In Illinois, now-pending Exelon-backed legislation would provide incentives and subsidies to “three reactors we think will close without policy action,” Crozat said. “States across the country are watching to see what the lawmakers there do.”
In New York, the Public Service Commission decided the new zero emissions credit (ZEC) in the state’s 50% renewables by 2030 mandate should go to nuclear facilities. Like renewables, the commission concluded, nuclear power protects against the “social costs” of emissions. Becaue of the value of the ZECs, Crozat said, “the Ginna, Fitzpatrick, and Nine Mile Point plants in upstate New York were going to close, but now they will not.”
“The New York ZEC is keeping those plants online,” Herndon agreed, “but if the program does not hold up against pending court challenges, I fear they will be at risk again.”
Crozat, like Herndon, assumes that emissions rise when nuclear plants are closed because they are replaced by fossil fuels. “That is what we have seen when plants were closed in Vermont and California.”
But planners in California do not think that has to be the case.
Unanticipated mechanical failures forced Southern California Edison (SCE) to cease operations at its 2,200 MW San Onofre Nuclear Generating Station on short notice in 2012 and shutter it in 2013. Though some milestone demand response and energy storage projects made up 261 MW of the needed supply, the 1,800 MW balance was replaced with natural gas generation. This confirmed nuclear advocates expectations.
“The California Air Resources Board said in 2014 that the state’s carbon dioxide emissions had increased by 9 million metric tons in the 12 months following the 2012 closure of two San Onofre reactors,” Revis James, a NEI vice president, recently wrote
In July, Pacific Gas and Electric (PG&E) announced it will shutter the 2,200 MW Diablo Canyon Nuclear Power Plant (DCNPP), California’s last nuclear facility, beginning in 2024. This changeover will, however, be deliberately planned, PG&E Electricity President Geisha Williams told Utility Dive at the time of the announcement.
Over the next nine years, she said, “our approach will be to have a highly integrated portfolio of renewable and other sources so we don't have to increase natural gas usage.”
PG&E’s approach is drawn from research in “Plan B,” a Friends of the Earth report based on a low carbon grid strategy developed by the Center for Energy Efficiency and Renewable Technologies (CEERT).
It replaces Diablo Canyon’s 18,000 GWh of yearly output entirely with energy efficiency, renewable resources and energy storage at a lower cost to customers than if PG&E kept the plant in operation, according to the utility's filing with the California Public Utilities Commission (CPUC).
The utility is now working on the initial 2,000 GWh energy efficiency procurement tranche, Williams said. “The second tranche, due between 2020 and 2025, will procure 2,000 GWh of least-cost, best-fit non-GHG-emitting resources through a competitive offering."
Keeping Diablo Canyon in operation would present three significant challenges, according to the Joint Proposal drafted by the utility and stakeholders and filed with the CPUC.
The first is an uncertainty of electricity demand due to increased customer adoption of distributed generation and energy efficiency and their turn to alternative electricity suppliers.
The second challenge is a decreasing need for Diablo Canyon’s baseload generation. With the advent of more variable generation, the new need, is for more flexible resources like geothermal power and storage from batteries, concentrating solar plants and pumped hydro to allow for better grid balancing.
The third challenge is solar and wind over-generation during off-peak periods, according to the filing. It will be necessary for California to use as much of that output as possible if it is to meet its 50% renewables mandate by 2030, and that means less demand for power from Diablo Canyon, particularly in months of low customer consumption.
Could California’s plan work?
Natural Resources Defense Council Senior Attorney Ralph Cavanagh helped develop the utility's Joint Proposal. What makes it possible, he said, is “a fundamental shift in PG&E’s thinking about its resource needs going forward.”
California climate and energy policies are making baseload generation “less relevant and less economic all the time” and placing “an increasing premium on flexibility,” he added. “A giant resource operating 24/7 is increasingly disconnected from the needs of the system.”
Crozat believes it will be challenging for most U.S. grid operators to integrate California's proposed emissions-free resource mix.
“Part of the challenge is how markets are organized and how large they are,” he said. “Another part is having the technology and infrastructure to integrate them and meet long term reliability and cost effectiveness concerns.”
Developing a highly diversified, emissions-free resource mix will require long term planning which will be especially challenging at this moment of significant policy uncertainty, he added.
“There is room for all these technologies in the portfolio but reliance on intermittent resources to provide power all day, every day, all seasons, takes a lot of intermittent resources,” Crozat said. “It is much easier to reach emissions reductions goals with nuclear and the other resources working together.”
Michael Shellenberger, President of the pro-nuclear Environmental Progress group, was even more adamant. “If they cared about climate change, why would they want to close our single largest source of clean energy?” he asked.
CEERT Executive Director V. John White said the answer is planning. “This will be the first opportunity to apply the principles of integrated resource planning with the low-carbon grid strategy. The key is a deliberate planning process that fits California’s resource options together in a cost-effective, reliable, low-carbon portfolio.”
Those who want to keep the plant open “would be right if the plan was to turn Diablo Canyon off tomorrow because then there would be no way to avoid replacing it with natural gas,” added CEERT Sr. Technical Consultant and Plan B lead author James Caldwell, a former utility executive. Good planning for 2024 can guarantee that doesn’t happen, he said.
Experiences in New York and California, where regulators are planning the orderly retirement of nuclear plants a decade in advance, could help other states seeking to keep plants online. But in the face of federal indifference to the climate problem, it will fall to state governments to recognize the threat and ensure any retirements are not replaced with emitting resources.
“We have to start planning now and we have to rethink how things were done in the past,” Caldwell said.