Sun Day analysis: Despite its recent peak, nuclear power has been declining for quite some time

Nuclear station

The following commentary was sent our way by the Sun Day campaign.

Tomorrow marks the 40th anniversary of the partial core meltdown of reactor number 2 at the Three Mile Island (TMI) nuclear plant near Harrisburg, Pennsylvania — the worst nuclear accident in U.S. history. [1] The event dramatically slowed what had – until then – been dramatic growth by the nuclear industry — 51 U.S. reactors were canceled between 1980 and 1984 and no new nuclear reactors were authorized to begin construction until 2012. [2]

However, most existing reactors continued to operate and many of those then under construction eventually came on-line, resulting in a slow increase in nuclear’s share of the nation’s electrical generation — until now.

The retirement of aging and costly reactors and their displacement by renewable energy sources – especially wind and solar – as well as natural gas strongly indicate that nuclear power in the U.S. peaked in 2018 and arguably years earlier. Its share of national generating capacity, electrical output, and domestic energy production are now all in decline.

Record-High Generation and Capacity Factor in 2018

As highlighted in a recent article by the U.S. Energy Information Administration (EIA), the one bright spot for the nuclear industry was record-high electrical generation by the nation’s nuclear reactors in 2018. U.S. nuclear power plants generated 807.1 million megawatt-hours (MWh) last year, slightly more than the previous peak of 807.0 million MWh in 2010. [3]

EIA attributes this new production record to a combination of added capacity through uprates and shorter refueling and maintenance cycles which allowed U.S. nuclear power plants to produce more electricity. EIA adds that shorter outage durations and balance-of-plant thermal efficiency improvements also led the U.S. nuclear power fleet in 2018 to experience its highest capacity factor on record: 92.6% — significantly higher than any fossil fuel or renewable energy sources. [4]

Such high levels of electrical output raise questions about whether the safety of aging plants is being compromised. Regardless of the answer, though, the electrical output and capacity factors recorded just before the 40th anniversary of the TMI accident were almost certainly the high-water marks for the nuclear industry. Multiple factors suggest a future of steady and probably accelerating decline for the U.S. nuclear power industry.

The Number of U.S. Reactors Continues to Fall

EIA data show that the number of U.S. nuclear reactors hit its peak in 1990 when 112 reactors held “full-power licenses, or equivalent permission to operate.” That number slowly dwindled in the ensuing decade to 104 by 2000 and continued to drop thereafter.[5]

Seven plants with a combined capacity of 5.3 gigawatts (GW) have retired since 2013. [6]

Only one new reactor has come into service since 2000. The Tennessee Valley Authority’s Watts Bar Unit 2 nuclear power reactor came online in October 2016 – followed by a rocky start-up – providing 1.2 GW of additional power. [7]

Thus, as of the beginning of 2019, EIA reports that the U.S. had 98 nuclear power reactors at 60 plants. [8]

However, two of those plants—Pilgrim, Massachusetts’s only nuclear plant, and Three Mile Island (unit 1) in Pennsylvania—are expected to retire later this year, based on announced retirements. In addition, three more are slated for retirement in 2020, and four more in 2021. In fact, U.S. nuclear capacity could fall by 10.5 GW by 2025 from the closings of twelve reactors [9] unless some are bailed out by billions of dollars in subsidies paid for by American citizens.[10]

On the other hand, the only new reactors under active construction are units 3 and 4 of the Vogtle nuclear plant near Waynesboro, Georgia. Whether they are ever completed is subject to speculation. The Vogtle reactors are more than five years behind schedule, and their construction cost has soared to as much as $28 billion. In fact, the Trump administration recently finalized $3.7 billion in additional loan guarantees to Southern Co. and its partners bringing the federal government’s total in loan guarantees for Vogtle to $12 billion. [11]

Nuclear Power’s Share of Total U.S. Electrical Generation Projected to Fall as Renewables Grow

Notwithstanding the record production in 2018, EIA expects that U.S. nuclear power output will decline in the near future as more nuclear plants close. In fact, in its “Annual Energy Outlook 2019” Reference Case, EIA projects that net electricity generation from U.S. nuclear power reactors could fall by 17% by 2025. [12]

That trend is already apparent.

As a share of domestic electrical production, nuclear power provided 19.18% of the nation’s electrical generation in 2018. A decade earlier (i.e., in 2009), its share was 20.22%. By comparison, over the past ten years, renewable energy sources (i.e., biomass, hydropower, geothermal, solar, wind) nearly doubled their share growing from 9.25% to 17.64% last year. [13]

And as nuclear output drops, renewables are poised to overtake it either this year or next. In its latest “Short-Term Energy Outlook,” for example, EIA projects nuclear power to provide about 19% of the nation’s electricity this year and next — i.e., experiencing no growth … and possibly declining further — but expects renewables to expand to roughly 20% by 2020. [14]

In fact, on a monthly basis, electrical generation by renewables has already outpaced that of nuclear power during four months in the two-year period 2017- 2018. [15]

A Slow Decline in Nuclear Power’s Share of Total U.S. Generating Capacity as Renewables Balloon

As a share of the nation’ total available installed generating capacity, nuclear power has been stagnant over the past half-decade with 107.98 GW of installed capacity at the end of 2018 compared to 107.32 GW at the end of 2013. Moreover, its share of total generating has actually dropped from 9.25% in 2013 to 9.02% today. [16]

Meanwhile, renewable energy’s share has been increasing rapidly — expanding from 15.97% in 2013 to 20.98% in 2018. The total generating capacity of biomass, hydropower, geothermal, solar, and wind combined is now 250.99 GW compared to 185.16 GW five years earlier. [17]

Thus, the installed generating capacity of renewables today is actually more than double that of nuclear power … and expanding rapidly. The installed generating capacity of wind alone may surpass that of nuclear power either next year or in 2021.

The retreat of nuclear power is even more dramatic when viewed as its contribution to total U.S. energy production and use (i.e., including energy for heating, transportation, industrial feedstocks and not just electricity).

In 2008, nuclear power accounted for 11.51% of total domestic energy production. By the end of 2018, that share had dropped to 8.84%. On the other hand, renewable sources were only 9.82% of total U.S. energy output in 2008 but had expanded to 12.26% a decade later. [18]

In fact, in terms of total U.S. energy production, renewables overtook nuclear power in 2011 and have been expanding their lead ever since. [19]

“The anniversary of the TMI accident, coupled with the subsequent Chernobyl and Fukushima disasters, marks forty years of failure by the nuclear power industry,” said Ken Bossong, Executive Director of the SUN DAY Campaign. “Fortunately, as the nuclear industry slowly fades into history, cleaner, safer, and less expensive renewable energy options are rapidly coming to the fore.”

“On the 40th anniversary of the Three Mile Island disaster, it’s clear that the sun is setting on nuclear power amid a rising tide of renewable energy—and that bodes well for our energy future,” said Tim Judson, Executive Director of Nuclear Information and Resource Service. “When it comes to the choices we make on energy and climate policy, that is one lesson we should take away from Three Mile Island. People called for the cancellation of Three Mile Island because of cost overruns, construction delays, and known technical problems. The utility proceeded anyway, and the reactor melted down after generating electricity for less than 90 days. The only thing that has ever successfully mitigated the environmental impacts of nuclear power is its lack of success as a technology. Pound for pound, nuclear has been the most heavily subsidized energy source in the country for over 60 years, yet it has never provided more than 12% of our energy. With much lower levels of public investment, wind and solar have achieved the most rapid improvements in technology and dramatic reductions in cost, and are sustaining growth rates that nuclear could never hope to achieve.”

Sources & Notes

[1] “Three Mile Island Accident,” Wikipedia, see:
[2] Id.
[3] “Despite closures, U.S. nuclear electricity generation in 2018 surpassed its previous peak,” U.S. Energy Information Administration, March 21, 2019; see:
[4] Id.
[5] “Annual Energy Review,” U.S. Energy Information Administration, September 27, 2012; see:
[6] “Despite closures, U.S. nuclear electricity generation in 2018 surpassed its previous peak,” U.S. Energy Information Administration, March 21, 2019; see:
[7] Id.
[8] Id.
[9] Id.
[10] Of the 12 reactors currently slated for closure by 2025, at least 7 of them stand little to no chance of receiving those kinds of subsidies or interventions: 2019: Pilgrim (688 MW); 2020: Indian Point 2 (1029 MW) and Duane Arnold (615 MW); 2021: Indian Point 3 (1040 MW); 2022: Palisades (811 MW); 2024: Diablo Canyon 1 (1118 MW); 2025: Diablo Canyon 2 (1122 MW). So a total of 6,423 MW of capacity will retire whether or not proposed bailouts go forward, with 4,183 MW of that retired by 2022.
[11] “Trump to Finalize $3.7 Billion in Aid for Troubled Nuclear Plant,” by Ari Natter, Bloomberg, March 19, 2019; see: ; and
[12] “Despite closures, U.S. nuclear electricity generation in 2018 surpassed its previous peak,” U.S. Energy Information Administration, March 21, 2019; see:
[13] “Electric Power Monthly,” U.S. Energy Information Administration, March 26, 2019; see:
[14] “Short-Term Energy Outlook,” U.S. Energy Information Administration, March 12, 2019; see:
[15] Renewables outperformed nuclear power in March, April and May 2017 as well as April 2018; see: “Electric Power Monthly,” U.S. Energy Information Administration, March 26, 2019:
[16] “Energy Infrastructure Update,” Federal Energy Regulatory Commission, (see table “Total Installed Generating Capacity); for December 2018, see: ; for December 2013, see:
[17] Id.
[18] “Monthly Energy Review,” U.S. Energy Information Administration, March 26, 2019; see:
[19] Id.

— Solar Builder magazine

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