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Mixing Coal and Solar To Produce Cheaper Energy 198

Al writes "It might not please many environmentalists, but a major energy company is adding solar-thermal power to a coal plant and says this could be the cost-effective way to produce energy while lowering CO2 emissions. Abengoa Solar and Xcel Energy, Colorado's largest electrical utility, have begun modifying the coal plant, which is based near Grand Junction, Colorado. Under the design, parabolic troughs will be used to preheat water that will be fed into the coal plant's boilers, where coal is burned to turn the water into steam. Cost savings comes from using existing turbines and generators and from operating at higher efficiencies, since the turbines and generators in solar-thermal plants are normally optimized to run at the lower temperatures generated by parabolic mirrors."
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Mixing Coal and Solar To Produce Cheaper Energy

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  • as that was my first thought too upon reading the headline =)

  • who would object? (Score:5, Insightful)

    by eighthave ( 319968 ) on Friday September 04, 2009 @04:46PM (#29316927) Homepage

    sounds good to me, donno any environmentalists who would object to burning less coal...

    • by Anonymous Coward on Friday September 04, 2009 @04:53PM (#29317027)

      your answer: its better then coal on its own but might be used as an excuse to avoid making solar/renewable a larger part of an energy plain, such as "we are green, we have coal solar power stations" rather then actually building any wind farms/etc

      • by commodore64_love ( 1445365 ) on Friday September 04, 2009 @05:07PM (#29317223) Journal


        Embracing a technology that is 50% solar-powered is still better than 0% solar power. Also many people forget that coal and oil ARE solar power - it's the sunlight that fell on our planet ~300 million years ago, and now exists in condensed form. Our challenge is not to stop using ancient sunlight completely, but to use today's sunlight. Converting plants to partial-solar is one step towards that goal.

        • Re: (Score:3, Insightful)

          by GameMaster ( 148118 )

          Actually, yes our challenge is to stop using ancient sunlight completely, eventually. Burning fossil fuels as a significant portion of our energy generation produces lots of nasty air pollution (which is bad for human health and the environment, even if you don't believe in global climate change) and almost guarantees a horrible economic crash once the resources finally start to run out (which will be in the not so distant future considering the amount we consume now and the rate at which that consumption

          • by commodore64_love ( 1445365 ) on Friday September 04, 2009 @06:14PM (#29318027) Journal

            WELL AS I SAID (but you apparently didn't bother to read): "this is one step towards that goal". You can not get to the second floor of your house in one leap - you have to take one step at a time. Today 50% solar/50% coal. Next decade 75% solar/25% coal. The decade after that 95% solar/5% coal power plants. Same applies to cars which are 10% electric/90% gasoline hybrids today, but eventually will be 95% electric with maybe a small gasoline generator for long-distance. But I guess shouldn't expect an environmentalist to understand that simple "transitional" principle. They are too busy pushing-over radio towers and then bragging about it - http://www.cnn.com/2009/CRIME/09/04/washington.towers.terrorism/ [cnn.com] I tried to make a reasonable statement, but all I got was a slap across the face. You will not win your cause by pissing-off other environmentalists who are on your side.

            I drive an 80mpg hybrid, light my house with 25 watt or lower bulbs, and turn-off the heat in the winter to help reduce my carbon footprint - and then some shitheads named the "Earth Liberation Front" go do this. These earth-worshiping religious wackos harm the cause; they don't help it. I'd like to set fire to every one of their offices, and see how they enjoy having millions of dollars of personal property destroyed.

            And if they really believe the AM radio waves are interfering with cellphones (impossible) or intercoms (probably but they are second-class devices anyway), then petition the FCC. That's why that organization exists.

            • Re: (Score:2, Flamebait)

              by GameMaster ( 148118 )

              This is how the logic of the discussion works out:

              • OP says he doesn't know why any environmentalist would object to this technology.
              • A poster responds with the premise that this technology might be used by the coal industry to justify continued implementatin of new coal plants or to claim we don't need to work so hard on alternative techologies
              • You interject suggesting that his comment doesn't matter ("So?") and add in the ludicrous suggestion that fossil fuels are just another form of solar energy. Were you,
          • The sad news is that we won't be running out of fuel any time soon. The output from fossil fuel sources will slowly decline over time though. However, there is a fairly little known thing called Fischer-Tropsch process [wikipedia.org] which is a way of converting coal into synthetic petroleum. This process works as long as you're willing to pay $50 USD / barrel for producing it. Since using coal releases about 20x more CO2 than fossil fuels and will not run out for hundreds of years even assuming increasing demand, this is
            • by BlueStrat ( 756137 ) on Friday September 04, 2009 @07:34PM (#29318905)

              We have the capacity to keep using fossil fuels for a couple of centuries still, so if we care about the massive self inflicted damage that would cause, we have to stop using dirty fuel sources for that reason, not because it makes economical sense to do so. It doesn't hurt to have cheap available solar cells though.

              I'm as much for a cleaner planet as anyone. However, people still have to live and afford to heat in winter & cool in summer. The higher that energy costs rise, the more poor people that will be freezing to death or dying from heat. People have to be able to afford to commute to work and to travel about for all the other things that living in a modern society requires.

              Farmers have to use tractors and other machinery to keep the food supply cheap enough to feed everyone. They also need energy to irrigate land (heck, right now California farmers are watching their crops die for lack of water and food will become more expensive and harder to get, especially for the poor/minorities/inner-city-dwellers, because environmentalists want to save a bait-fish rather than feed people). Grocery stores have to refrigerate the food. Trucks have to bring the food to the stores.

              That's the disconnect that many environmentalist types suffer. They put a clean environment and animals ahead of the lives of people, refusing compromise so human lives may be preserved and then wonder why they make so little progress.

              When environmentalists are willing to seriously damage the nations' food supply because of some perceived risk to a bait-fish's population numbers as in the current situation in California, it makes all the other perfectly reasonable environmental proposals that much harder to get taken seriously by the general public and the politicians. At least by those politicians that need to worry about getting re-elected, as many are in districts with voters that would re-elect them no matter what they did short of turning into Satan Himself on national TV and clubbing baby seals live in HD.

              I'm sure there will be numerous environmental groups that will come out against this, as they won't be able to see past OMGZ!! COAL!!! and realize it's a step in the right direction.


            • Re: (Score:3, Informative)

              by Jeremy Erwin ( 2054 )

              Since using coal releases about 20x more CO2 than fossil fuels and will not run out for hundreds of years even assuming increasing demand, this is bad news for stopping the use of fossil fuels based on economic reasons.

              Huh? Coal is a fossil fuel.

      • Re: (Score:2, Informative)

        Given how crappy wind farms are as a power source, I don't think that's a very good example.

    • by ciroknight ( 601098 ) on Friday September 04, 2009 @04:56PM (#29317081)
      A rabid unshaven hippie environmentalist might bring notice to the fact that this is just spending more money propping up coal, rather than investing the money directly into pure green energy (such as a pure solar thermal power plant replacing the coal burning one). But the fact is, there's no way this money would have went to pure green energy in the first place, so they should really be pleased that they are even bothering to try to green their coal plants at all.
      • Re: (Score:2, Insightful)

        by SBrach ( 1073190 )
        I agree, 10 years ago no one was going to try and sell a all-electric car, it wasn't commercially viable. So they designed hybrids instead. The hybrid technology is what has allowed us to build electric cars today. Many "environmentalists" would argue that hybrids are evil because they still emit CO2 but without them we probably wouldn't have the battery tech, regenerative braking, and weight reduction techniques required for all-electrics today. This plant is the same deal. If continuing to burn some
        • Re: (Score:3, Informative)

          by moosesocks ( 264553 )

          I agree, 10 years ago no one was going to try and sell a all-electric car.

          False [wikipedia.org].

          • by c6gunner ( 950153 ) on Friday September 04, 2009 @05:35PM (#29317603)

            So you link to an article which confirms his claim, and label it "false"? In what universe does THAT make sense?

            • Re: (Score:2, Informative)

              by moosesocks ( 264553 )

              So you link to an article which confirms his claim, and label it "false"? In what universe does THAT make sense?

              Howso? I linked to an article that notes quite clearly that GM marketed and sold all-electric cars from 1996 to 1999. Hybrids have never been of much interest to GM.

              The economics of the EV-1 are hotly contested, given that it was an entirely new platform, and so few were produced. Although I can't confirm the theories that the program was cancelled for political reasons, the allegation is certainly plausible.

              • Re:who would object? (Score:5, Informative)

                by c6gunner ( 950153 ) on Friday September 04, 2009 @07:12PM (#29318685)

                Howso? I linked to an article that notes quite clearly that GM marketed and sold all-electric cars from 1996 to 1999.

                Marketed .... ok, depending on your definition. Sold ... definitely not, as the article you linked to clearly explains:

                On December 5, 1996, GM began delivering the EV1s to its selection of carefully-screened lessees ... Although the car could not be purchased outright, its MSRP was quoted at $34,000.

                The economics of the EV-1 are hotly contested

                In the same way that evolution is hotly contested - ignorant people make straw-men arguments and conspiracy-theories persistently raise their ugly heads, while people who actually know what they're talking about shake their heads in amazement.

                Again, from the article:

                According to Dennis Minano, then-GM Vice President for Energy and Environment, "Is it what our customer wants?"[11] GM was not alone in its denunciation of electric vehicles as a viable alternative to the gasoline car; according to Robert J. Eaton, then-chairman of Chrysler, "The question is whether the market is ready for the product... if the law is there, we'll meet it... at this point of time, nobody can forecast that we can make [an electric car].

                None of the automakers expected to create a viable electric vehicle by the set deadline, but they had no choice other than to try. If the EV1 had not been scrapped, it's possible that it may have found a niche-market, kinda like the Segway. Whether such a low level of sales would have been enough to justify development costs is debatable. Either way, it's clear that EV's weren't ready for mainstream use in the 90's - they didn't have the range, they cost too much, and they took much too long to recharge.

                Hell, Tesla Motors is having problems making pure electric vehicles TODAY for mainstream use, and they have the advantage of better technology in general, and much better battery technology in particular. I like the idea of buying their sedan once it becomes available, but I'm not a big fan of forking over $50,000 for it. And their financial figures reflect the difficulty of the project - if the government hadn't bailed them out with $400 million, it's likely that the company would have folded.

          • by geekoid ( 135745 )

            And people avoided it in droves.

          • Re: (Score:3, Informative)

            by madsenj37 ( 612413 )
            From wikipedia, "While customer reaction to the EV1 was positive, GM viewed the program as evidence that electric cars occupied an unprofitable niche of the automobile market, evidenced by their ability to lease only 800 units in face of production costs of US$1 billion over four years." Granted they tried to lease and not sell, but only 800 units leased over four years is small no matter how you cut it. And with only a 55-75 mile range, they only appeal to some urban and suburban dwellers.
            • by Hadlock ( 143607 )

              The whole program was all kinds of fail. You don't "lease" a subcompact car in 1995 America. The idea of an adult driving a new car like a metro or a caviler was a joke back then. People bought and leased full sized cars based on the cheap cost of gas. People lease a BMW or Mercedes, or at least something that's usually more expensive than joe six pack can buy used on three month's income used. This car looked like a geo metro (face it, it's true), performed about as well (looks like it anyways, this is the

        • Well, sort of. Regenerative braking has been used in electric vehicles since the early days of motorized transportation. Check Wikipedia. In addition to the examples they mentioned I'm pretty sure the GM EV-1 used one, too. As far as battery tech goes, there are plenty of incentives to work on it. Weight reduction has long been important in all types of vehicles. Hybrids cars are pretty complicated in their own right and a lot of the research has been toward making the more complicated powertrain work

      • The trick isn't whether or not money was spent developing this technology. The trick is in deciding where this should be implemented and what it means for the future of coal as a technology. Sure, it makes sense to implement this, and any other feasible clean coal technology, in older plants as those plants aren't going to go away for a long time. However, what we shouldn't be doing is allowing the coal industry to use this, or similar, technology as an excuse to build new plants or lobby for a decrease

      • Exactly it. Bemoaning that they should have spent the money on pure-solar instead woud be ridiculous, given the facts.

        The company from TFA owns a coal power plant. It was very expensive to build, and still has a lot of life span left. The odds of them suddenly saying "lets tear down this money-making plant right now and build a solar plant instead" is nil to none.

        Spending money improving the green credentials of the plant is the best anyone should expect of them. If it turns out to be aa good business decis

      • As long as this is only being used to retrofit existing plants frankly I applaud them for thinking outside the box for once. This sounds like an excellent way to boost efficiency and mitigate the harm otherwise done. If this was used to justify new coal plants I think I'd be a bit more concerned...
    • Re: (Score:2, Insightful)

      I don't object to burning less coal, I object to burning coal. It puts Uranium and Thorium into the air. Population radiation exposure is greater form a coal fired plant than a nuclear plant.
      • "Population radiation exposure is greater form a coal fired plant than a nuclear plant."

        No Three Mile Chernobyls! Karen Silkwood died for our sins!

        We must power our civilization with solar, ponies, and solar ponies.

    • You don't? I can't go a month without seeing at least one anti-nuclear power protest where I live.
  • Environmentalists (Score:3, Insightful)

    by treeves ( 963993 ) on Friday September 04, 2009 @04:47PM (#29316941) Homepage Journal

    Why would it not please them...if they are rational?
    But maybe the answer is contained within the question....

  • by dfetter ( 2035 ) <david@fetter.org> on Friday September 04, 2009 @04:47PM (#29316945) Homepage Journal

    It turns out that you can turn CO2 into fuel by exposing it to a titanium oxide catalyst in the presence of sunlight. In a closed cycle, this would be a carbon-neutral way to go. http://dsc.discovery.com/news/2009/03/23/carbon-dioxide-fuel.html [discovery.com]

    • by piemonkey ( 1628149 ) on Friday September 04, 2009 @05:02PM (#29317153)

      It turns out that you can turn CO2 into fuel by exposing it to a titanium oxide catalyst in the presence of sunlight.

      That's just another form of solar power, it's just you're using the sunlight to produce fuel rather than electricity. If it's more efficient than solar electrical generation (very possible) then it's a good idea, it's bound to be more efficient than biofuels, but whether it's more efficient than solar water heating, I don't know.

      You'd probably need a concentrated source of CO2 for that, so it would either reduce efficiency, by using some energy to concentrate CO2, or would use existing power plants outputs, meaning it's not carbon neutral.

      Everyone should read this http://www.withouthotair.com/ [withouthotair.com]

    • Interesting. I'd soulike to know how efficient this is in storing solar energy (any less than the 10-15% now possible via solar cells. Also, what are the production costs and can it be scaled up, or is this destined to remain in the lab?

      Ultimately, nature has a million-year R&D advantage over us - plants are the only true carbon-neutral solar fuel collectors really over a full product life cycle.

  • by Rei ( 128717 ) on Friday September 04, 2009 @04:47PM (#29316953) Homepage

    Why wouldn't environmentalists be happy with this? I consider myself one and think this is great news. Too many people focus on 100% solutions. You don't need to eliminate 100% of coal in the short term. Reducing coal consumption by 80% or so by having solar provide heat during peak hours (daytime) would still be a huge benefit.

    • by Nadaka ( 224565 )

      Well, since the goal is to retrofit existing coal plants to make them more efficient, it sounds good to me.

      Though it is hardly a replacement for building new nuclear or fully solar thermal plants in the long run.

    • by markdavis ( 642305 ) on Friday September 04, 2009 @05:12PM (#29317299)

      >Reducing coal consumption by 80% or so by having solar provide heat

      The article says:

      "At the most, the contribution from solar power at existing plants will probably be no more than 10 to 15 percent of the electricity produced." "For the Colorado project, the share will be more like 3 percent"

      Although I agree with the spirit of what you said, it is not THAT much contribution by solar :)

      • by Rei ( 128717 )

        I see no reason why it couldn't be expanded, however. They're starting small, and that's fine, but it would seem like the upper bound is to have solar provide 100% of the power on sunny days (during peak hours), and coal provide the rest. Sort of like SEGS in California, which provides 90% with solar and the other 10% with natural gas.

    • Why would they object? The Nirvana fallacy. If you could convert the USA to 99.9% solar, and one single coal plant in the entire country, environmentalists will say "This is an imperfect solution, so it should be scrapped so we can save that money for when we find a 100% green solution"
      • by geekoid ( 135745 )

        No, we will not.
        We would welcomes it; now some group(coughgreenpeacecough) use the Nirvana fallacy,as well as many lies, to keep there agenda going. The agenda being getting more money for Greenpeace.

        In fact, if we had a goor [propgram, we could get to 50% solar in 10 years, and 80% solar in 15.

        • Not to mention the opposite side ::cough::shills::cough:: using the Nirvana fallacy:
          If solar and wind energy can only meet (numbers out of nowhere for the sake of presentation) 80-90% of the electricity grid's needs, all solar and wind projects should be scrapped and we should continue to rely on coal. Right?
          I never understood why otherwise reasonable people preface their posts by saying they "aren't liberals" whenever this topic comes up, but this is Slashdot. I must be new here.

    • by geekoid ( 135745 )

      At beast, it would reduce comsumption by 15%.

      Is that beteer then building a 500MW Industrial Solar Thermal plant?
      Beats me, but it is something to be considered.
      Not that I'm against a 15% reduction in coal use.

    • Personally, I look at this as a good solution to the problem of existing plants that can't be gotten rid of right now because the alternatives aren't ready yet. I would only have issues if the coal companies tried to use this tech as a way to justify the building of new plants or to lobby for a reduction in spending on alternative technologies. I can see why people would be justified in being wary of the coal industry's intentions here.

    • Re: (Score:2, Insightful)

      by Anonymous Coward
      I never understood why traditional power plants need cooling ponds or cooling towers. Couldn't they just use the heat from low pressure steam to pre-heat the water before it goes back into the boiler?
  • Come on people... (Score:2, Insightful)

    by Anonymous Coward

    The solution is nuclear freaking power. Even China realizes this now.

    We've been in the Atomic age for 60 years now and still don't have a majority of our energy from nuclear energy. It's such a disgrace.

    • Re: (Score:3, Insightful)

      by WindBourne ( 631190 )
      And I am THANKFUL that it is NOT the majority. I want it to be a larger part of our matrix, but we need to maintain a matrix of power. The problem with coal is that it is ~50% of America's power. If it was around 33%, then we would not have these issues. In particular, we would not be worried about the idea of losing more of it. We need more nuclear, but not majority.
  • This idea seems so obvious one is left to wonder why it hasn't been in use since the 1973 energy crisis?
  • From TFA...

    What's more, the only coal plants that can be augmented by solar are those in sunny areas with enough nearby land to accommodate the mirror arrays.

    Why couldn't a small array be put on the roof of a landlocked coal plant? Granted, the smokestack would cause relatively small shadows in parts of the array as the sun moves across the sky, but as long as the array is large enough to work with (say) 10% failure, then wouldn't a small array still be useful?

    • by tsotha ( 720379 )
      I'm guessing the roof of a coal plant ends up being covered with a layer of decidedly non-reflective soot.
      • coal plants are not allowed to release "soot" and besides, soot is unburned fuel! The coal plant near me has mechanical and electrostatic scrubbers to remove the particulates; and, chemical scrubbers to remove the sulpher dioxide.
    • by geekoid ( 135745 )

      Becasue there isn't a lot of room on the roof of a coal plant.

  • This does not make any sense to me. A coal plant has scads of waste heat at high enough temperatures to preheat any amount of water. Exactly where does solar heat fit into this picture? It seems like an expensive way to heat water and as a consequence, let more hot coal gas get away.

    • Re: (Score:3, Informative)

      by ThreeGigs ( 239452 )

      A coal plant has scads of waste heat

      Let me fix that for you:

      A coal plant has scads of low quality waste heat

      Don't forget, your waste heat is what's necessary to condense the steam on the other side of the turbines. You *must* have some waste heat, otherwise there's no heat differential, thus no mechanical work can be extracted.

      • Re: (Score:3, Informative)

        by smoker2 ( 750216 )
        The waste heat is currently lost to the atmosphere in the cooling towers. There is no reason not to be running the cold input water through a heat exchanger to recapture some of that waste heat. This is how efficiency works.

        The mechanical work comes from superheating the water and letting the steam turn turbines. In other words, you ADD heat - it makes no difference what the exhaust is used for as the work has already been done. There is no useful work being done by having the steam condense back to water
    • I seem to recall that the exhaust temperature was cool enough that the liquid cooling water was returned to the river.
    • Err, use less coal to heat a given volume of water?

      Can't help with waste heat, clearly.

  • by Doc Ruby ( 173196 ) on Friday September 04, 2009 @05:32PM (#29317563) Homepage Journal

    If it displeases environmentalists, it will be because it's still really bad for the environment. Using solar to preheat the water instead of more coal to preheat it just admits that solar is a more effective tech for generating energy than coal is. Any coal still burned is still polluting the Greenhouse, creating huge and unmanageable costs just a little down the road (and downwind, the typical "coal is clean" illusion).

    They should just convert the entire plant to solar. But coal is too subsidized for them to abandon it, and its lobbyists have too tight a chokehold on the government for solar to have an equal shot at economic efficiency.

    • by geekoid ( 135745 )

      no, coal is a more effective tech for getting energy. It does show that it is a cleaner tech.
      The energy density from coal is higher.

      The area for get equal power from a Industrial Solar reactor(it's 24/7 as opposed to panels) is pretty high. We should be building the like gang busters, but there may be a space issue where the coal plant it. Ultimately, the long term plan needs to be a on getting rid of them.

    • Re: (Score:3, Insightful)

      No, if it displeases environmentalists, it will be because it displeases environmentalists. The correlation between things that are clean and good for the environment (such as nuclear power), and the things that please environmentalists is not very strong.

    • Uhmmm. No. (Score:3, Insightful)

      by WindBourne ( 631190 )
      I was the post above that said I have been trying for nearly 4 years to get Colorado to do this approach. Lets talk economics of this. Many cities have 1-4 SMALL coal plants (typically about 100 MW) that are located in there. Because they were built in the 50-70, they are much older and not as efficient. Many companies want to get rid of them and bring in GW size plants. These monster would be located on the outer fringe and would then have to transport lots of electricity for a long haul. That is wasteful,
  • still not clean (Score:5, Insightful)

    by beckett ( 27524 ) on Friday September 04, 2009 @05:34PM (#29317593) Homepage Journal

    There have been many attempts of late to greenwash coal, this solar project and the "clean coal" concepts being the most recent incarnation. Even if 100% of coal plants can be made 100% carbon neutral, where do they get the coal from?

    in December 2008, a 40 acre ash pond in tennessee [nytimes.com] broke through its walls and flooded millions of gallons of coal ash, potentially far worse than the Exxon Valdez. This is one of the largest environmental disasters that has happened in the US, and there has been little to no national coverage about this accident.

    There are a lot of heavy hitters in the coal industry that want to put the best possible face on coal (e.g. Montana), and it is alarming that 'mountaintop removal', the laziest way to get coal, is frequently not discussed when considering how green a coal plant can be.

  • by roc97007 ( 608802 ) on Friday September 04, 2009 @06:07PM (#29317945) Journal

    When I make a cup of tea in the microwave, I can put in a cup of cold water and set the timer for 3 minutes, or I can fill from the "hot" tap, put in a cup of warm water, and set the timer for 2 minutes. Using solar to preheat the water means less coal burned for unit power. Even if you weren't trying to reduce your "carbon footprint", this is still an excellent thing to do.

  • Running some water through reflected sunlight before said water is heated by burning coal isn't solar energy, either.

  • When the water cools I imagine it's a lot of water, so would it be practical to have the steamed water hit a ceiling after it turns a turbine and then run down back onto another, maybe smaller, turbine? Is this already done?

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