Nuke vs. Solar: The Carbon Calculus
NEWS: How life-cycle emissions stack up for various fuels—plus, the nuclear breakdown
April 28, 2008
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A given energy source doesn't simply pollute—or not—as it's converted into electricity. There's also mining, plant construction, transportation, and other factors to consider. Looking at the big picture is the point of life-cycle numbers like these, expressed in grams of carbon dioxide equivalent per kilowatt-hour of electricity created.
Lifetime carbon emissions by source (g/kwh)
Coal: 1,006
Oil: 742
Natural gas: 466
Solar: 17 to 39
Nuclear: 16 to 55
Hydro: 18
Geothermal: 15
Wind: 14
The U.S. Nuclear Breakdown
Mining and milling: 1.7 (g/kwh)
Includes unearthing and transportation of uranium to refining and enrichment facilities
Enrichment: 13
By far the most carbon-intensive part of the fuel cycle, enrichment is needed to concentrate uranium isotope U-235 from its natural level of 0.7 percent to the 4 percent required for reactor fuel. The United States uses a gaseous-diffusion enrichment method that gobbles 40 times more energy than the gas-centrifuge process used in Europe, but a planned switch to centrifuge enrichment will shrink nuclear's domestic carbon footprint significantly. Once enriched, the uranium is shaped into small pellets and inserted into fuel rods.
Construction: 1.5
Building a nuclear power plant takes time, hundreds of thousands of metric tons of steel and concrete, and billions of dollars. It also requires lots of diesel trucks and industrial machinery, which translates into greenhouse gas emissions. Fortunately, a nuclear plant should last 40 years or more, which helps reduce its overall emissions per kilowatt-hour.
Plant operation: 3.9
Fission doesn't produce CO2, but replacement of spent fuel rods, plant heating, and other routine procedures do put a small load on the environment.
Temporary storage: ~1
Nuclear plants must store their own waste on-site or at an approved temporary site until Yucca Mountain is allowed to receive it. Transporting and storing the waste creates its own minor carbon footprint.
Nuclear total: ~21 g/kwh
If the industry switches entirely to centrifuge enrichment, the total will fall to around 12 g/kwh.



http://www.energynews.co.za/web_mai n/article.php?story=20080311120936953
I appreciate you asking for a source... that is always my first question, too.
Here is a source I found. The IAEA is a United Nations sponsored group that deals with all matters nuclear. Their researchers came up with the following which mirrors the info above somewhat. I have over many years reviewed IAEA's work and found it to be fairly objective.
http://www.iaea.org/Publications/Ma gazines/Bulletin/Bull422/article4.pdf
Dave: You posted this reference in another MJ forum. The link does not work and I asked that you look at this and re-post.
For others, energynews.com is South African "environmental" website that posts energy related articles/opinions.
Thanks much,
Bruce
SolarEnurgy.net
I posted the IAEA reference. Ike asked the same question you are from the opinion piece...where did the author get the numbers.
The major reason for nuclear coming out so well is the tremendous amount of electricity generated for the amount of GHGs created throughout the cycle. Likewise, solar and other options do poorly in this comparison due to the limited amount of electricity generated.
Thanks for the reply. So who is the author of this piece and where is the source for the "Nuclear Breakdown"?
It would be helpful to know. Thanks.
Just announced: Shell pulling out of large UK wind project. For the details, see:
http://www.renewableenergyworld.com /rea/news/story?id=52368&src=rss
Here is what interests me...
The UK wind project will provide 1000 megawatts of electricity and cost around $4.75 Billion. If those costs are accurate (certainly they will inflate with the increased demand for wind turbines and labor costs), that comes to $4750 per kilowatt-hour. That is at least equal to if not more to a new nuclear power plant of the same size.
Here is the other subtle point people miss:
Wind power may generate electricity 30% of the time compared to a nuclear power plant that generates 100% of the time 24/7, except for a 30 day refueling outage every 18 months. So do the math:
Assume both wind and nuclear can be built for $4750 kw-hour.
Assume 95% capacity factor for nuclear (18 months/19 months) and 30% capacity factor for wind.
Now the cost per kw-hour is $5000 per kw-hour for nuclear and $15,833 per kw-hour for wind.
The 70% of the time the wind does not blow must be made up how? Build more NG or coal plants. That not only increases GHG emissions, but adds to the overall cost per kw-hr.
How long are we going to misuse capitol and facts? How long before we establish a rational national energy policy?
Now that I have your attention... apply the same thought process to Solar power.
Arizona Public Service is looking at a 280 megawatt solar project that they say will cost $1 Billion.
http://www.aps.com/main/green/Solana/FAQ.html
This project will cost $3571 per kw-hour...if it were making electricity 24/7.
Assume APS gets 12 hours per day of full power...which is very much an overestimation even with the molten salt bed backup they plan to employ.
Now the real cost is $7142 per kw-hr. And this is IF they build it. See the fine print in their FAQs...
"Like all renewable projects currently under development, successful completion is contingent upon a number of factors, including the extension of the federal renewable energy tax credit..."
The only way APS (and other companies)can make a solar or wind project even close to profitable is if they get a huge federal and state tax credit to offset the exhorbitant construction costs.
In fairness, this is the same credit given to other "green" generators, including nuclear.
Barry, I'd say look at the full picture and consider a mix of what you say is more costly (though ONLY if we can manage to avoid accidents at nuclear facilties...or major hits by terrorists.) Consider the thousands of years areas like those surrounding Chernobyl will continue to cause negative effects on living creatures.
Why not go with low heat Geothermal (heat pumps), solar PV, wind, hydrogen from hydrocarbon fuels or other efficient extraction methods, tidal, wave, thermal gradient, and more. Decommissioning nuclear plants always costs far more than estimated. As long as no private firm insures the Nuclear establishment against accidents, leaving the US Govt. (us) to fill this void...this is what's telling.
What happens though when you have an unusually calm day and the stifling heat causes an increased load on the grid?
http://blogs.wsj.com/environme ntalcapital/2008/02/28/no-bree ze-the-day-the-wind-died-in-texas/
Our sources of hydroelectric are currently for the most part tapped out. There are no more locations, unless you want to continue to divert water supplies with the current problems of droughts and floods.
I'll avoid going into big oil's attempt to fatten their pocketbooks with the ethanol movement driving up food prices, not to mention the wonderful efficiency associated with it.
Nuclear power has had a few problems in the past. One is Chernobyl, another TMI, and there has been only 3 fatalities in the U.S. (SL-1 incident 1961, not radiation related). Those fatalities like Chernobyl were largely due to safety systems turned off and standard operating procedures ignored. My large problem is the immediate write off of people to nuclear power when they don't understand the technology. The overall safety of the nuclear industry is so pristine compared to the oil welling and refining industry, the paper industry, any chemical manufacturing industry, etc. I am beginning to get disheartened that few people can still analyze and process all sides of an issue as opposed to latching on to whatever they currently read in a headline or saw on a blog. I do not want to sound preachy but it takes more than reading a brochure from Greenpeace to understand the full situation. Let's stop looking only at trees and worry about the forest.
Thanks for your measured response and thought-based questions.
I support a blend of electrical generation sources... but for baseload, 24/7 power, nuclear is the best option.
Current government data at www.eia.doe.gov, shows that in 2007 installed wind generators provided power to their customers by state anywhere from 3% to a max of 38% of the time...for a national average of 25%. So which six hour period of the day do you want your power? btw... solar is even less available.
You and many others talk about the taxpayer support of nuclear power. That is a misperception. The customers that enjoy nuclear power, which is produced at a cost per kilowatt-hour equal to or less than coal-fired plants, pay for decomissioning costs and high level waste disposal in their electric rates. Currently $7B sits in a government trust fund to pay for high level waste storage. The Price-Waterhouse Act provides an insurance cushion, not full coverage... and it only pays out IF there was an accident. So it really costs us nothing. Even the NRC, our regulator, is paid for by the nuclear owners through annual fees and hourly rates of over $240/hr, which again, is passed on to the rate payers, who are indeed tax payers, but not as a tax but more as a user fee.
Regarding construction costs... look again to the eia website for their objective analysis of contruction costs on a per kilowatt-hour basis. Then consider the sources availability and operating costs. Based upon wind's 25% availability, you have to build 4 times the number of windmills to equal one 24/7 available nuke. In addition, those wind mills and other alternative energy sources would not be built if not for a direct state and federal tax credit...that's right... a huge tax credit that if not there... construction would cease. I can provide you a host of sources on this... including many Mother Jones wind advocates who are crying about the expiration of the current tax credit legislation that expires at the end of this year.
Also...the long lasting effects around Chernobyl... ask the people living in two very large rebuilt Japanese cities about the long lasting effects of radiation. Sure...it's above normal levels but so is taking a high altitude cross-country airline trip at 40K feet.
Either nuclear wastes and dangerous, either they're not.
If they are not, there is no need to bury them: why to pay so much for nothing?
If they are, to bury them would be the worst solution. We can hope that Science would one day discover a way to neutralize them, it would be so silly to have sent them underground definitively...
Does anyone has a more recent publication?
The facts for nuclear is completely non-sense. Moreover, taking into account only CO2 emissions for evaluating nuclear industry is also non-sense.
What is infinite is human capabilities to invent and adapt. Nuclear is definitively to banish, just as Austrian Constitution says it.
If you believe the research done by an international scientific agency is inaccurate, provide a better source of peer evaluated and validated research for us to review. Otherwise, your opinions are just that...yours.
Regarding constitutions, several European nations (and states in the US) are now re-visiting their rash reaction to left wing wingnuts in the 70s and 80s, including revising their constitutions to promote nuclear power.
Nuclear waste is deadly if not handled properly. At this point, there are no documented deaths from nuclear waste. Can you say the same be said for the thousands of deaths/year attributed to fossil plant emissions?
Nuclear waste disposal is a political issue, not a technical one.
Keep opposing nuclear power and you delay the replacement of green house generators. You are contributing to the very boogey man you fear most... global warming.
Dave: Dave
I believe your 20M number of "scared New Yorkers" might be overstated. However, remember that no on has ever died as the result of commercial nuclear power in this or any other Western country....ever. Perhaps New Yorkers should spend their "scared" efforts on real threats such as terrorists, chlorine gas tank ruptures, glass falling from high rises, cranes falling on high rises, muggers, and oh...and riding in cars with politicians. These have in fact caused great harm to New Yorkers.
As far as living near one... I live nine miles from one of the largest and I feel very safe. My biggest threat is driving home tonight and hitting one of the many white tail deer that seem to have a death wish.