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Published on December 23rd, 2010 | by Susan Kraemer


Compared Gram for Gram, Solar is Ten Times More Powerful than Nuclear

December 23rd, 2010 by  

An interestingly novel way of comparing solar power with nuclear power finds that solar easily bests nuclear. Ken Zweibel has an analysis at The Solar Review, that compares the two kinds of electrical energy, in terms of how much power is packed into each gram of its respective material: cadmium telluride, versus uranium.

He provides data showing that CdTe thin film solar power (using cadmium telluride) takes ten times less PV material to make 1 kilowatt hour of electricity, than nuclear uses of uranium, to make an identical 1 kilowatt hour of electricity.

This is even comparing the two as if solar “used up” each gram of cadmium telluride the way that nuclear power uses up its uranium fuel (pretty much – some can be recycled, theoretically). But of course, solar doesn’t burn up fuel. You can get electricity from the same grams of PV material for at least thirty years, and then the material can be recycled and still used again.

By contrast, the equivalent grams of nuclear uranium must be replaced with newly mined uranium once the first has yielded its energy.

Here’s his math. It takes 12 grams of CdTe to make a one square meter solar thin film module.

“In a year in an average US location, we harvest about 11% x 1750 kWh/m2-yr, or 154 kWh/yr (after accounting for another 20% in losses)” he notes.

So we need 0.08 of a gram per kilowatt hour for one year’s supply of electricity. But that assumes we’ve used up the gram by the end of the year.

“But wait!” he cries. “We don’t burn PV modules, and they don’t die after one year – warranties are about 30 years, so this is really one thirtieth of that, or 2.6 milligrams per kWh”.

So, compared with nuclear, solar packs a punch: using one-tenth as much material to make the same power.

But check out the comparison to coal. According to his calculations, even assuming just thirty years use, then tossing the solar, the thin film photovoltaic material uses just five millionths of the weight of coal needed to make the same kilowatt hour of electricity.

“Compared to coal, of course, the numbers are out of this world. These differences in resource needs bear on the ultimate sustainability of the PV in comparison to other more resource-intense energy technologies”.

Indeed. Solar looks to provide us with not just a cleaner, safer and healthier form of electricity, but also, one that is much more sustainably mined. It takes just a fraction of the stuff from the earth that coal or nuclear takes.

Image: Two Crabs
Susan Kraemer@Twitter

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About the Author

writes at CleanTechnica, CSP-Today, PV-Insider , SmartGridUpdate, and GreenProphet. She has also been published at Ecoseed, NRDC OnEarth, MatterNetwork, Celsius, EnergyNow, and Scientific American. As a former serial entrepreneur in product design, Susan brings an innovator's perspective on inventing a carbon-constrained civilization: If necessity is the mother of invention, solving climate change is the mother of all necessities! As a lover of history and sci-fi, she enjoys chronicling the strange future we are creating in these interesting times.    Follow Susan on Twitter @dotcommodity.

  • Bob_Wallace

    Timothy, renewables vs. nuclear comes down to one important number. The cost of electricity produced.

    Wind is now under 4 cents per kWh. Without subsidies.

    Solar is now under 8 cents per kWh. Without subsidies.

    The cost of wind and solar will continue to decline.

    The LCOE for the Vogtle plants is now running over 12 cents per kWh. With subsidies.

    It is unlikely that more reactors can be built as cheaply as the Vogtle reactors. They received extraordinarily low financing rates. Those rates are highly unlikely given that we are now out of recession.

    You can count up the amount of steel, concrete and copper. You can measure the energy density of uranium, thorium, sunshine and breezes. You can fiddle around with land required. But it all comes down to what gives us electricity for the least money.

    If you’ll take a look at what is happening in the world solar installations are accelerating. Wind installations are accelerating. Nuclear is losing ground.

  • Bob_Wallace

    Kewaunee was in good condition with years to go on its license. The owners closed it because they were losing money. Exelon has six reactors that have been losing money for over five years. Oyster Creek is going to be closed as it cost too much to bring up to standards. The two SONGs reactors were judged too expensive to repair, they were making little money.

    MSR – when/if someone builds one and demonstrates that it can produce electricity at a competitive price then we can put nuclear into consideration. Current technology in use is simply too expensive.

  • Bob_Wallace

    There is an ample amount of steel, copper, and other recoverable materials in both wind and solar farms to pay for the cost of their removal and the return of the site to original conditions.

    In the US nothing gets carbon credits. Nuclear has received vastly more in subsidies than have wind and solar. The new nuclear plants being built in Georgia and South Carolina will receive higher subsidies than will wind and solar. In fact, wind and solar installations will soon lose their subsidies, both technologies have progressed where they are our first and second least expensive ways to bring new power online.

    I have no idea what you do in Australia. Seems to me, though that you’re installing solar and watching your government prostitute itself to the coal industry.

  • Bob_Wallace

    No, Michael, I’ve read a lot about MSRs and other nuclear ideas. I’ve read enough to realize that it is almost certain that nuclear is a dying industry.

    Apparently you are not reading. The price of storage is dropping rapidly. 14% per year is the most recent number that I’ve seen. I know very well that wind and solar are reducing the amount of fossil fuels consumed.

    Michael, you would be best served by getting your head out of the nuclear industry misinformation feed and educating yourself.

    Now, please no more misinformation. Best you read the site commenting rules.

    • Michael Pelizzari

      Nobody can predict the future, Bob, but if you’re right, and the world does replace fossil fuels with renewables and storage, with no help from nuclear, then biodiversity of the natural world is certain to take a nosedive. Why do you think the guys who wrote “An Ecomodernist Manifesto” went to the trouble? Many of them were as anti-nuclear as you until they looked at the numbers of people populating the Earth and their future needs, and examined what it would take to sustain them.

      In your estimates of future energy demand, have you counted the energy it will take to bring CO2 levels down enough to reverse sea level rise and ocean acidification? Have you counted the energy needed to synthesize hydrocarbons for transportation and the production of concrete, tasks currently dependent on the burning of fossil fuels? And have you decided which open spaces must be sacrificed to harvest all that energy from the sun?

      What good is a renewables only energy policy it cannot save the biosphere from carbon dioxide poisoning without paving over vast tracts of the natural world? Your nuclear-free future might be livable for humans and their pets, but would leave precious little for thousands of species that need open space NOT overrun with people and their structures.

      • Bob_Wallace

        “Nobody can predict the future, Bob, but if you’re right, and the world does replace fossil fuels with renewables and storage, with no help from nuclear, then biodiversity of the natural world is certain to take a nosedive

        You say that nobody can predict the future, and then you do exactly that. And, IMHO, get things wrong. Let me explain why.

        First, we can move to 100% renewables/storage without doing anything more than minor damage to animal and plant life. Very close to zero chance of lowering biodiversity.

        Wind farms use very small amounts of land and kill far fewer birds per GWh than nuclear but even nuclear wouldn’t eliminate a species of anything. Solar has about zero impact on plant or animal life. About the only significant species damage that could be done by renewables would be badly placed dams.

        Obviously the real threat to biodiversity is fossil fuel produced climate change. And acification of oceans.

        We have to stop the use of fossil fuels. And nuclear isn’t a good choice.

        First, it takes far too long to bring new nuclear plants online. We can install a “reactor’s worth” of wind in less than a year and a get the job done even quicker with solar. That means a decade less of coal burning.

        Second, the cost of nuclear is so high that utilities would delay building new reactors until they had no other option. Coal and natural gas plants would continue to be operated until they could be operated no longer. OTOH, wind and solar are lowering the cost of electricity and some utilities are beginning to install wind and solar as cost cutting measures. Economics will drive the installation of wind and solar faster and slow nuclear builds.

        I would suggest that you consider the fact that the people who wrote “An Ecomodernist Manifesto” are simply wrong.

        The nuclear route to a fossil fuel free future would be a slower, very much more expensive route than a renewable energy route. (And there’s the problem of radioactive waste.)

        • Bob_Wallace

          “In your estimates of future energy demand, have you counted the energy it will take to bring CO2 levels down enough to reverse sea level rise and ocean acidification? ”

          The first job is to get fossil fuel CO2 and other human greenhouse emissions to zero. That will not be enough to reverse sea level rise nor to reduce acidification.

          Renewables will get us to zero CO2 faster and cheaper than would nuclear.

          How we bring down the level of atmospheric CO2 or ‘sweeten’ the oceans past that is a problem for which we do not yet have any good solutions. I doubt we will be able to reverse sea level rise, at best we could slow the rise. (I’m not predicting that no solution might be found decades from now.)

          What we can do right now is to quit making things worse. Double the amount of wind and solar we are installing per year, then double it again, and then double it once more. Hold rates at that level or better and we can stop fossil fuel CO2 emissions before 2050.

          Right now the world is getting about 12% of its total energy from renewables and about half that from nuclear. That means we need to move about 2.5% of our total energy consumption from fossil fuels to low carbon generation over the next 35 years. Actually, less than 2.5% as much of the energy consumed via fossil fuels is wasted. If we can start switching 2% of the energy we use (rather than waste) to low carbon we should have no problems hitting zero by 2050.

          While we slow and stop emissions our ‘best and brightest’ can continue to look for possible ways to remove and sequester carbon.

          Sea level rise. I think our option is only to choose the rate at which polar land ice and glacier ice melts. I don’t see how we could cool the Earth down enough to start replacing glacier ice within the next 100 years.

          • Bob_Wallace

            “And have you decided which open spaces must be sacrificed to harvest all that energy from the sun?

            What good is a renewables only energy policy it cannot save the biosphere from carbon dioxide poisoning without paving over vast tracts of the natural world?”

            Such a tiny amount of “open space” will be used for solar that it isn’t worth worry. We have far more existing rooftop, parking lot, train track overheads, landfills, brownfields, burned out agricultural land, and “low value” land than we’d ever need for solar. Besides, solar doesn’t take land out of use by plants and animals. Plants grow beneath solar racks and small animals thrive (they’re protected from raptors).

            Let’s look at the US. Assume we end up getting 40% of our energy from wind, 40% from solar and the other 20% from hydro, geothermal, tidal, biomass/gas.

            It would take about 150,000 3 MW turbines to produce 40% of the 4,143 TWh (terawatt hours) of electricity the US used in 2010. Foundations, access roads, transmission and ancillary buildings for those 150k turbines would use 36,040 acres. 0.0015% of US land area.

            To produce 40% of 2010 US electricity with PV solar we’d need to cover ~3,250 square miles with 20% efficient panels. That’s ~ 0.1% of contiguous 48 states. Existing rooftops, parking lots and brownfields would be more than enough.

            We’re moving to larger and more efficient turbines and more efficient solar panels. The 0.0015% and 0.1% areas will shrink.

          • Bob_Wallace

            Let’s put that 0.0015% and 0.1% area into perspective.

            “Some 40% of the world’s land surface is used for the purposes of keeping all 7 billion of us fed — albeit some of us, of course, more than others. And the vast majority of that land — about 30% of the world’s total ice-free surface — is used not to raise grains, fruits and vegetables that are directly fed to human beings, but to support the chickens, pigs and cattle that we eventually eat.”


            “Overall, 83 percent of the total land surface and 98 percent of the areas where it is possible to grow the world’s three main crops—rice, wheat, and maize—is directly influenced by human activities.”


            We’re talking a tiny, tiny, tiny amount of land that would be used for wind and solar. And you seem to still be ignoring the “all in” footprint of nuclear. Don’t look at only the reactor footprint and leave out the large amount of land needed for fuel extraction and refining.

          • Bob_Wallace

            I hadn’t read “An Ecomodernist Manifesto” recently. I remembered agreeing with a lot of what they had to say but disagreeing with them on the nuclear issue. I just reopened my copy and let me quote out some stuff for you…

            “Urbanization, agricultural intensification, nuclear power, aquaculture, and desalination are all
            processes with a demonstrated potential to reduce human demands on the environment, allowing
            more room for non-human species.”

            There is no mention of renewable energy. For a paper written by a large number of people involved in climate change and energy issues do you think that a casual overlooking?

            “Nuclear fission today represents the only present-day zero-carbon technology with the demonstrated
            ability to meet most, if not all, of the energy demands of a modern economy”

            That is clearly incorrect. Jacobson and Delucchi demonstrated the ability to furnish all the world’s energy needs with renewables in 2009. Their findings have been supported by multiple additional studies. This information was widely known well before the Manifesto was written and it wasn’t even mentioned.

            “In the long run, next-generation solar, advanced nuclear fission, and nuclear fusion represent the
            most plausible pathways toward the joint goals of climate stabilization and radical decoupling of humans from nature.”

            Finally they acknowledge solar. But they fail to mention any of the other renewables. This was written two years after China had started generating more electricity from wind than from nuclear.

            “Next generation solar”? This generation solar is all we need. There’s no need to invent something better. (Better would certainly be welcomed, but not necessary.)

            I’m sorry. This group of people, well concerned as they are, are simply too biased to be taken seriously. I cannot excuse them based on a lack of knowledge. They are obviously not reporting the full story in order to promote nuclear energy.

  • Bob_Wallace

    You think we don’t know about capacity factor?

    Why did you leave out the land requirements for uranium mining, refining and waste disposal in your nuclear number?

    Can you put nuclear on top of buildings and over parking lots?

    Best to not accuse others of presenting biased arguments by using a biased argument.

    • Michael Pelizzari

      “Bob, calm down. We support on-structure solar. But that doesn’t help the variability problem, so stop confronting nuclear without facts.

      What you do miss is power density, which for nuclear is far higher than any source, as well as far more reliable than any source. When the sun don’t shine, one needs a reliable source.
      ;]” – Alex Cannara

      Alex was blocked from posting this comment. Since it’s one I agree with, I agreed to post it for him. Now I’ll add my own. Given the land requirements of solar, anybody who advocates using open space to harvest solar power who thinks he’s an environmentalist is kidding himself. As Timothy Weaver pointed out, nuclear plants leave about 100 times more room for nature than solar farms with the same average power output.

      • Bob_Wallace

        Density is only one factor in determining the cost of electricity produced by a given technology.

        Uranium is energy-dense, but the capital cost and financing cost of turning that dense energy source into electricity makes it too expensive to be competitive.

        Here’s a map that shows how much of the Earth’s surface would need to be covered with solar panels were we to get all, 100%, our electricity with solar panels. Those very small green rectangles.

        Now since we’ll likely get about 30% from solar you can carve those boxes down to about one third their current size. And take them even smaller as panel efficiencies rise.

        Most of that solar is going to go on rooftops and over low value land. So little land will be taken away from “nature” that it simply won’t matter. Worry more about Walmart parking lots.

        The US would need about 2,500 square miles of panels to produce 30% of its electricity with solar panels. That’s less than 0.1% of the land in the lower 48 states.

        According to the EPA we’ve got 23,400 square miles of brownfields. Almost 10x what we’d need for solar.

        In summary, nuclear is energy dense, it has a smallish lifetime carbon footprint, the plants themselves take only modest amount of land, but the positive aspects do not offset the large problem of cost.

        • Michael Pelizzari

          I think you have ignored the fact that we would need 4x as much land because solar is intermittent, making 10,000 square miles. Humans already crowd nature out of more than their share of real estate, don’t you think? Why gobble up more than we have to? You also ignore the energy requirements of future remediation of the damage we have caused to the global environment. Alex Cannara has calculated the energy cost of reversing ocean acidification before it destroys the marine food chain. The U.S. share of that alone could double our future power requirements for decades.

          You’re also wrong about the cost of nuclear plants. They’re only expensive to build, but operating costs are trivial in comparison. Today it costs Diablo Canyon Power Plant only 4 cents per kWh to produce electricity. Future nuclear plants, such as molten salt reactors, are expected to bring the cost down to 3 cents per kWh, and their so-called “waste heat” could be used to desalinate seawater, make fertilizer, and synthesize hydrocarbon fuels from water and carbon dioxide. I’d like to see solar do THAT.

          • Bob_Wallace

            I’ll give you my numbers. You can check them out.

            100% from solar.

            2013 Total US Demand = 4,045,855 million kWh
            Average Daily Demand = 11,084,534,247 kwh
            Add 20% for Storage and Transmission Loss = 13,301,441,096 kWh

            Total Number 1 kW Panels (64 sq.ft. each) = 2,955,875,799 (Assuming 4.5 avg solar hours per day)
            Total Area for Panels = 189,176,051,142 Sq. Ft.
            Total Area for Panels = 4,342,884.5 Acres
            Total Area for Panels (Square Miles) = 6,786 Sq. Miles

            Add 20% Area between rows of Panels = 8,143 Sq. Miles

            Area needed for 40% solar 3,257 Sq. Miles

            Square Miles in Lower 48 States = 2,959,064

            Percentage of Lower 48 to Gen 40% for all 50 States = 0.1%

            San Bernardino County = 20,105 sq miles
            16% of San Bernardino County

            According to the EPA we’ve got 23,400 square miles of brownfields.

            Check it out….

            Alex talks a lot of crap. That’s why he lost his commenting privileges here.

            Nuclear is simply too expensive and takes too long to bring on line. I’ve listed nuclear’s strong points. They are outweighed by nuclear’s weak points.

            “You’re also wrong about the cost of nuclear plants. They’re only expensive to build, but operating costs are trivial in comparison.”

            Sorry. That is incorrect. Approximately 25% of paid off US plants are in financial trouble due to high operating costs. Some have already been closed. Kewaunee’s operating costs were around 5 cents per kWh. Higher than the non-subsidized cost of wind. Kewaunee was in good operating conditions and had years to go on its license but it was closed down.

            Others are fighting off bankruptcy, attempting to get some sort of bailout by either governments or consumers. Exelon has five or six reactors that have been losing money for over five years. At some point the company is going to get tired of bleeding money.

            More existing nuclear plants will find themselves in trouble as the price of wind and solar continue to fall. All it will take for most is a single big repair bill to push them over the edge.

            Besides. how would we go back and build more reactors 30 years ago so that they would now be paid off? Got a time machine in your garage?

            ” Future nuclear plants, such as molten salt reactors, are expected to bring the cost down to 3 cents per kWh”

            That’s horse poop. MSR still requires a reactor and a steam plant. You can’t build massive stuff like that and cut overall construction cost – and time – by 75%. If someone is telling you junk like that you should be very wary of anything they claim. It simply cannot happen.

            Michael, the world is moving away from nuclear. Two proposed reactor builds were canceled last week. Russia just announced that they are ‘postponing’ any further builes for at least a year.

            If there was any chance that a reactor could be built and produce electricity for even 5 cents per kWh large corporations such as GE would be building reactors using their own money.

          • Michael Pelizzari

            Okay, the 4 cents per kWh from Diablo Canyon must have just included incremental cost and not life cycle costs. I got it from an article about their cost of energy to desalinate seawater. I agree that the current fleet of Generation II reactors are money losers, but they’re environmental winners for their small footprint.
            There are thousands of ways to produce nuclear power, one being the MSR. MSRs are much safer, simpler, and more efficient, so they should be much less expensive to build, That’s why Alvin Weinberg, co-inventer of the LWR, championed them at Oak Ridge National Lab and was fired by the Nixon Administration for his trouble. Your dismissal of them simply because they require a reactor and steam plant shows you don’t know how they differ from LWRs, so why don’t you read about them? A good place to start would be Wikipedia’s article about ORNL’s “Molten Salt Reactor Experiment”.
            My figure of 3 cents per kWh came from the book “Thorium: Energy Cheaper than Coal”, by Robert Hargraves and did include life cycle costs. But cost per kWh will not be the main reason for going nuclear, the environmental costs of alternatives for base load power (fossil fuels or renewables+storage) will be, as an increasing number of environmentalists are concluding.

          • Bob_Wallace

            Let’s start with land footprint. Anyone who claims that nuclear has a vastly smaller footprint than wind is not including the land needed for fuel extraction and refining, for mine waste, and radioactive waste disposal. Or they are exaggerating the footprint of wind and solar.

            You can get a handle on the land use issue here –


            “There are thousands of ways to produce nuclear power, one being the MSR.”

            There are at least a few different ways. Most of them are old ideas that have been floating around for a long time. As you point out MSRs go back to the days of Tricky Dick.

            Here’s the question you need to ask yourself. If there are superior ideas that would produce electricity for “5 cents” a kWh then why are they not being built?

            Can’t blame China’s, Russia’s, France’s or South Korea’s failure to move on to these more “advanced” designs on Nixon. Or any other US president. Or on the US DOE. Or even on Greenpeace.

            If one of these designs would produce inexpensive electricity then why did the Chinese/French group not purpose one for Hinkley Point, instead bidding to build “16 cent” nuclear? A price that, by the way, seems to be killing the project.

            If someone stated that thorium reactors would produce 3 cent electricity they were simply lying. There is absolutely no way to build a reactor for 3 cents per kWh. Perhaps the statement was only about operating costs. Actually, some of our paid off reactors have operating costs less than 3 cents, so that doesn’t make much of a case for thorium if it would be 3 cents.

            Consider that some/all of the CANDU plants could be run on thorium. I don’t believe any are using thorium. If thorium was considerably cheaper than uranium don’t you think CANDUs would be using thorium?

            According to the World Nuclear Institute the average fuel cost at a nuclear power plant in 2013 was 0.79 cents / kWh. Less than a penny. Switching to a free fuel wouldn’t make nuclear affordable


            ” But cost per kWh will not be the main reason for going nuclear, the environmental costs of alternatives for base load power (fossil fuels or renewables+storage) will be, as an increasing number of environmentalists are concluding.”

            A small number of people who seem to be poorly informed as to the relative costs of nuclear and wind/solar have stated support for nuclear. I think you’ll find in the greater environmental community nuclear is being sidelined. Wind and solar prices are simply too low and still dropping.

            Wind + solar + other renewables + storage offers an economic package against which nuclear energy has no chance for survival.

            And the environmental costs for wind and solar are much less than for nuclear. When a wind turbine fails we don’t have to establish an exclusion zone around it. When a solar panel wears out we don’t have to let it “rot in place” for 60 years so that it’s safe enough to haul away to a hazardous waste facility.

            In the US we have 15,000 abandoned uranium mines which have to be evaluated and cleaned up.

          • Michael Pelizzari

            If you need to ask,
            “Here’s the question you need to ask yourself. If there are superior ideas that would produce electricity for “5 cents” a kWh then why are they not being built?”
            , then you obviously haven’t read anything about MSRs. The reason their development was halted in the 1970’s was as simple as vested interests getting the Nixon administration to strangle the competition in its cradle. Alvin Weinberg’s 8 MW thermal MSR reactor was so successful that the next step, scaling it up to commercial size, would almost certainly have produced a design that would make MSR power much cheaper than LWR power. That would have ruined the existing solid core nuclear and fuel rod fabrication industries, whose sunken costs might never have been recovered without continued LWR sales and operations. And as you are well aware, Richard Nixon was very responsive to the needs of vested business interests.

            But do not despair. A NASA guy named Kirk Sorensen uncovered the Oak Ridge National Labs’ research reports in old filing cabinets, and uploaded them to in 2006. Since then, researchers all over the world have been poring over ORNL’s meticulous documentation. Now it’s just a matter of time before MSRs are developed, maybe not in the US, whose regulatory environment is hostile to any reactor that isn’t solid core, but certainly elsewhere. If Americans don’t get smart about energy very fast, they will probably end up buying MSRs from China.

            You really need to learn about MSRs before you comment on the subject again.

          • Bob_Wallace

            Michael, it’s 2015. 2006 was almost a decade ago. MSRs and other nuclear ideas are simply dropping by the wayside.

            Let it go, son. Start paying attention to what is happening in the energy world. Amazing things are happening as we transform our grids from 20th Century to 21st Century technology. You’re pushing for better typewriters during the dawn of the computer age.

          • Timothy Weaver

            You “green” energy supporters promised solar would power the world in the *1970’s*. It’s laughable that you of all people would complain about a nine year old site.

          • Bob_Wallace

            Are you saying that someone in the 1970s claimed that solar power power the world or that someone claimed that solar would power the world in 1970?

            Most of us who keep up with what is happening in energy are fairly sure that solar will provide a substantial part of the world’s energy. Perhaps 40% or even a bit higher. It will likely take us about three decades to get to that point.

            Of course that prediction assumes there are no unexpected ‘breakthrough’ technologies which prove out to be better.

          • Timothy Weaver

            The Topaz Solar Farm requires 9 million panels, each 8 sq ft, to generate 125 MW of power on average. That’s about 1.74 watts per sq ft. 64 sq ft panels would only average out 111 watts per panel, not 1 kilowatt. Even disregarding the 12-hours without daylight, that’s only 222 watts per panel. And the location of the Topaz Solar Farm has higher than average sunlight compared to the rest of the country. Those panels would produce even less power. IOW: your claims don’t match empirical evidence.

          • Bob_Wallace

            1.74 x 64 = 111.4 watts per panel. The site should average five solar hours per day so about 0.5 kWh on average per day.

            You math is wrong.

            And First Solar thin film panels are lower efficiency than silicon panels.

  • Snake Oil Baron

    Cadmium telluride? Why not do the comparison with silicon PV which is currently dominating the market? Is there enough of these raw materials to supply a good fraction of humanity’s future energy use while still supplying other uses for these substances? Solar might be useful in a lot of instances but I would be surprised if nuclear wasn’t the go-to power for certain contexts given that it can be used in places where vast tracts of land and/or unshaded roof space are not available.

    Uranium and coal mines look nasty at close range but are tiny areas of land compared to the whole. They can be reclaimed though it takes a while so enviros can always show early days of reclamation and claim it proves that reclamation is inadequate.

    As for nuclear waste, two types of radioactive elements are produced: short half-life ones which are economically and medically valuable and long half-life ones that are less dangerous and can be easilly stored until uses are found for them.

    • Susan Kraemer

      (Re Cadmium telluride?) As I remember, the author worked in the thinfilm biz, so he had the numbers at hand.

  • Pingback: Solar Compared (Gram for Gram) to Nuclear and Coal – climate change and environmental news()

  • Thomas Cheney

    I am wondering about the total amount of material like concrete and steel. Some fiqures show solar and nuclear similar in terms of life cycle GHG emissions. Also, what about storage for photovoltaics?

  • zafar

    good info about both solar and nuclear energy.

  • Bill Woods

    Of course this an apples-vs.-oranges comparison. For grins, I looked up how much fuel solar power actually takes: 6.2 e11 kilograms of hydrogen per second. That illuminates the Earth with 1.74 e17 W = 48 TW-h per second. Converted to electricity at 20%, that would be 10 TW-h/s. So solar power’s fuel consumption is about 60 kg/kW-h (60 million mg/kW-h).
    This could be improved enormously by building a Dyson sphere to capture the sunlight which doesn’t illuminate anything of consequence.

    On the other hand, fissioning uranium or thorium produces about 940 GW-days/tonne of heat. That works out to a fuel consumption of about 0.15 mg/kW-h of electricity. Current technology only uses about 1% of the energy in natural uranium; the flip side of that is that the ‘spent’ nuclear fuel and depleted uranium which have already been mined still hold a fantastic amount of energy.

  • Akhilesh Magal

    I don’t think this is a fair comparison. Remember in nuclear energy, the fuel is Uranium. In Solar the fuel is not CdTe, it is the conversion technology. So when we do such a comparison we need to compare fuel v/s fuel and conversion technology v/s conversion technology. Here we do a mix-match. Although it gives us numbers that we can admire, they convey a wrong picture (i.e Solar is much more efficient in material consumption than Nuclear).

    • Susan Kraemer

      Or you are restating the author’s point: uranium gets used up (fuel), while solar does not have to be fed a fuel that gets used up.

      • Akhilesh

        Exactly! That is why such a comparison is not very useful. It can lead an uninformed observer to the wrong conclusions.

    • Emily Wilson

      You’re right, Akhilesh, that this ‘comparison’ of Zweibel’s is more of a thought exercise than a fully-worked technical evaluation.

      A true comparison of current fuel efficiency between solar and nuclear systems would not use the parameters of the older, less-efficient thermal reactors.

      I would Zweibel’s post as a jumping off point for your own thinking. Do not use it as the basis for an honest technical argument with anyone qualified to argue the subject.

      When considered in that light, one hardly needs to go to the depth of calculating the comparative efficiency of power generative systems to know that solar has an obvious advantage in that its raw material is guaranteed to our planet for billions of years, while nuclear has an obvious advantage of continuous availability.

      These advantages cannot be directly compared. And any attempt to do so will raise honest questions such as yours.

    • WV Treehugger

      Uranium mining is just another way to destroy our Earth,blowing Mtn’s to heck. Just like good ole Mtr. Coal mining does. Solar energy leaves the Earth,Mtn’s and vital water sources untouched. Which in return leaves us with clean air,water and Mtn’s. The Sun will never get used up,to me there are no comparisons.

    • EL

      Uranium also has to be developed on the front end to be used as a fuel source: refining from naturally occurring ore into yellowcake, conversion (into uranium hexafluoride), enrichment, and fuel fabrication. These are very intensive energy processes at the front end, and sometimes result in high carbon emissions and pollution (which author includes via StormSmith). The crucial variable for solar is not conversion of materials, but variability of light source (latitude, cloud cover, etc.). Not sure of the author’s assumptions on this basis.

  • Chaitanya Patankar

    This is such an awesome thing to know

    Solar is very much preferred as compared to nuclear..
    Go Solar Goo!!

  • Jack Enright

    This is fantastic news. I would like to add that if you couple a passive solar design with active solar panels for a residential home or commercial office you could add to the efficiency of Solar energy with a similar lifetime of at least thirty years.

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