Wednesday, June 22, 2016

California to Close Diablo Canyon Nuclear Plant

Subtitle: Solar Power to Replace Nuclear

It won't be right away, instead the closures of the two remaining reactors in California will be in 8 and 9 years from now, respectively, in 2024 and 2025.   That news rang across the nuclear camp yesterday, as PG&E, the plant's owner and operator agreed to shut the plant down at those dates and not seek a 20 year extension for the operating license.  Many articles on this are available, one from the Wall Street Journal (see link) does a credible job.   Title: "PG&E to Close California’s Last Nuclear Plant by 2025 - It will be cheaper to shut down Diablo Canyon facility and find replacement power, utility says."
Diablo Canyon Nuclear Plant, image from Google Maps 2016
Arrow indicates twin reactors.   Pacific Ocean to the bottom right.

There are some interesting, biased, pro-nuclear articles too, mostly from those who seemingly cannot believe their beloved nuclear plants are being shut down, instead of being built in greater numbers.   Those articles grind on and on with their favorite themes: jobs lost if nuclear plants close, grid instabilities if nuclear plants are not there to anchor the fragile grid, save-the-planet with carbon dioxide-free power from nuclear plants, and of course the old stand-by, coal and natural gas prices might increase again someday.   What many of the pro-nuclear articles omit is the great capital cost that PG&E would incur to keep the plant running past 2025, and how much money the plant is losing by operating in the present economic conditions. 

Much of the hoopla and angst stems from the pledge by PG&E, one of California's largest utilities, to replace the 2,200 MW of electricity presently provided by Diablo Canyon with a mix of wind, solar, storage, and efficiency improvements - all at no additional cost to the consumers electricity bills.  

Taking the above list of four tentative reasons to keep the nuclear plant online, in order, with jobs first.   The plant employs approximately 1500 people, per PG&E.   Jobs and their loss are also trotted out by other nuclear plant owners across the nation, as those plants are shut down.  The company is to work with various unions to keep some employed to perform the decommissioning (more on that expensive fiasco later), transfer some to other jobs within the company, and perhaps provide severance packages to others. 

Second, the California grid is not at all fragile.  The simple fact is that Diablo Canyon is a drop in the bucket in the California electricity market; only 2,200 MW out of approximately 35,000 MW average production, or approximately 8 percent.   On a high-demand day, when demand reaches 45,000 MW (as it did yesterday), the nuclear contribution is a much smaller portion at only 5 percent approximately.  It is also a fact that another, equal-sized nuclear power plant dropped offline forever in 2012 when the SONGS (San Onofre Nuclear Generating Station) had multiple tube ruptures and spewed radioactive steam into the sunny skies of Southern California.   SONGS' 2,200 MW removal from the grid did not create any blackouts, rolling or otherwise.   The ISO, California's Independent System Operator, simply called for more production from the gas-fired power plants.    Also, in the four years since that time, California has installed at least 7,000 MW of solar power plants.   The grid's frequency stability is assured by the gas-fired power plants, and large hydroelectric plants.  

Third, saving the planet by producing power that is free of carbon dioxide emissions is required only by the false-alarmists who believe that CO2 will overheat the Earth's atmosphere.   CO2 in the atmosphere certainly has not produced any appreciable, nor alarming warming thus far.  

Fourth, the tired ploy of gas shortages that nuclear advocates used in the 60s, 70s, and 80s no longer works.  Natural gas is no longer in short supply with a high price, nor is it likely to ever be in that situation again.  The simple fact is that gas exploration companies know now how to use precision directional drilling (PDD) and hydraulic fracturing to good advantage, producing natural gas in surplus amounts.  The wholesale price is now under $2 per million Btu, due to PDD and hydraulic fracturing.   This is a world-wide practice, not limited to the US.   

So, then, what of the naysayers' claims that substituting wind, solar, and increased efficiency will replace the 2200 MW from Diablo Canyon?    Again, as above, the fact is that California added more than triple in solar MW compared to what was shut down at SONGS.  (7000 vs 2200 at SONGS).   The grid remains stable, blackouts did not occur.    

The wind resources in California are nearly fully exploited, as the state has only three economic locations for wind turbines at Altamont Pass, Tehachapi Pass, and Banning Pass near Palm Springs.   Any future capacity growth would be from retired wind turbine replacements with modern, more efficient turbines.   In addition, state-wide data shows that California's wind power plants have a lower-than-average utilization rate, or annual capacity factor compared to the states in the Great Plains region.  In good years, the wind provides approximately 26 percent capacity factor, and in poor years about 22 percent.   In contrast, the Great Plains states have capacity factors of 35 to 42 percent on an annual basis.  Using rough numbers, 40 for the Great Plains and 25 for California, a wind turbine would produce 60 percent more power in the Great Plains (40/25 = 1.6).   However, the costs to install and operate would be effectively the same.  It makes great sense to build wind turbines in the Great Plains but not in California.  

Increased solar power has some intriguing aspects that will be discussed next.   One major point (allegedly) in the Diablo Canyon shutdown agreement is that PG&E will procure 55 percent of its electricity from renewable sources.   This is 5 percent more than the 50 percent that state law mandates by the year 2030.    As wind power is not likely to increase much, the logical candidate is solar power.  The state has ample sunshine that presently produces approximately 8000 MW at noon (recent data from CAISO).   With a total annual power demand of 300,000 GWh, half by renewables then is 150,000 GWh.  Wind and other non-solar renewables in 2014 produced 34,000 GWh, leaving 116,000 GWh for solar to produce.   With the annual average capacity factor for California utility-scale solar of 26 percent (per EIA and California Energy Commission), the state would then require 51,000 MW of solar installed. 

And there lies the problem.  The solar arrays produce too much power for the grid to absorb on any given sunny day.  51,000 MW of solar output greatly exceeds the typical summer day's peak demand of 35,000 MW.   What, then, to do with all that mandated solar power?    One solution, already proposed and under consideration, is to store at least a portion of the solar energy output as hot oil, or molten salt, to be re-produced as electricity later at night.   Yet another is to increase the pumped storage hydroelectric capacity in the state, and store the energy by pumping water into elevated lakes.   A third solution is to store some of the excess solar energy in grid-scale batteries.   A fourth solution is to store some of the excess solar energy in gravity-based heavy rail storage systems, as the ARES system in Nevada will do when construction is complete.  

Update 1: 6/23/2016 -  More uses for excess electricity include a fifth solution - split water via electrolysis, store the hydrogen for later and produce electricity when needed via fuel cells; and sixth, have a multitude of electric vehicles on smart chargers to charge the batteries with excess power.   --- end update 1

It is an interesting time to live in California.  The last nuclear plant will close in less than a decade.  Solar power plants will be built in great numbers.  The electrical grid will not only survive, it will thrive.   Innovations and economics will, as always, combine to sort out the favored solutions to the various challenges that arise.   

Another article will discuss the expenses of keeping Diablo Canyon online, and why it makes economic sense to shut it down. 

Roger E. Sowell, Esq.
Marina del Rey, California
copyright (c) 2016 by Roger Sowell - all rights reserved

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