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Earth Power Science

Tech That Will Save Our Species - Solar Thermal Power 648

NoMoreCoal writes "Salon has up a story by Joe Romm, former undersecretary of energy during the Clinton administration, discussing a lesser-known alternative energy solution. It's a technology that (he claims) is ready to provide zero-carbon electric power big, fast, cheap and (most importantly) right now: solar thermal power. 'Improvements in manufacturing and design, along with the possibility of higher temperature operation, could easily bring the price down to 6 to 8 cents per kilowatt hour. CSP makes use of the most abundant and free fuel there is, sunlight, and key countries have a vast resource. Solar thermal plants covering the equivalent of a 92-by-92-mile square grid in the Southwest could generate electricity for the entire United States. Mexico has an equally enormous solar resource. China, India, southern Europe, North Africa, the Middle East and Australia also have huge resources.'" Interesting stuff, even if he does mention the Archimedes Death Ray.
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Tech That Will Save Our Species - Solar Thermal Power

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  • Re:pie in the sky (Score:2, Informative)

    by morgan_greywolf ( 835522 ) * on Tuesday April 15, 2008 @09:57AM (#23076786) Homepage Journal

    1) How much toxic materials will be required to create and maintain a 92-by-92-mile square grid. 92 *MILES*, people. like parent said, the size of New Jersey.
    And the vast majority of the American Southwest is completely unoccupied by people or farms or really much of anything.

    For you environmentalist types who can't tolerate the thought of drilling for oil off the coast, what do you think a 92 square mile solar blanket will do to the native wildlife?
    That would have to be studied, of course, but we're talking about a relatively small area of the American Southwest, which is mostly high desert.

    3) How will this power be transmitted to consumers? Voltage loss is a real issue for long-distance transmission.
    Actually, a study was done recently (with a summary published in Discover magazine about 2-3 months ago) that confirms that only a 10-15% or so increase in efficiency is required for the long-distance transmission and that the study's authors, all experts in the field, felt that this was possible by 2020.

  • Re:Hmmm.. (Score:3, Informative)

    by Lemmy Caution ( 8378 ) on Tuesday April 15, 2008 @09:58AM (#23076790) Homepage

    Of course, it begs the question:
    Sigh.

    No, it doesn't.
  • by arashi sohaku ( 228013 ) <thunderwizard@gmail . c om> on Tuesday April 15, 2008 @10:05AM (#23076902)
    Check the summary again. It says "equivalent", not one big 92x92 plot of technology. If the solar fields could be made smaller, but many more spread out over the region, you could get the same effect as if it were one large setup.

    I heard about this on NPR last week, and this same concern was brought up. No one is saying that they are going to make such a huge array (can you imagine the need for maintenance workers?). However, if there are enough arrays created, it can be the functional equivalent of the 92x92 field spoken about.

    Thunder
  • by xaxa ( 988988 ) on Tuesday April 15, 2008 @10:14AM (#23077024)
    Has anyone even read the summary? It says plants. That means more than one.

    Solar thermal plants covering the equivalent of a 92-by-92-mile square grid

    There are some pictures of the German plant here [google.co.uk].
  • by tinkerghost ( 944862 ) on Tuesday April 15, 2008 @10:23AM (#23077166) Homepage
    And improvements in magnetic confinement could easily bring fusion power down to 6 to 8 cents per kilowatt hour...and advances in the production of antimatter could yield power too cheap to meter

    The big difference of course, is that there are commercially operating solar/thermal power plants running - with a cost of ~15cents/KWh. Nobody has an operating fusion plant dumping electricity into the grid - dito with antimatter.

    Given that the existing plants are experimental, it is entirely possible that future plants can improve efficiency - through improved design/scale - to drop the price to between 6 & 8 cents.

  • by llZENll ( 545605 ) on Tuesday April 15, 2008 @10:29AM (#23077238)
    Well if you would actually read the article rather than spouting off empty criticisms you would know that heat is MUCH easier to store than electricity, and you would only need a plant big enough for average load as you can store extra heat during off peak usage and use it during peak load.
  • Re:pie in the sky (Score:4, Informative)

    by Smidge204 ( 605297 ) on Tuesday April 15, 2008 @10:46AM (#23077482) Journal
    1) Not a hell of a lot. This is solar thermal, not solar photovoltaic, so there are basically no nasty chemical processes. Some vapor deposition for making mirrors but that's about it.

    2) No doubt it would change the local environment, but considering it's currently desert the change would probably improve conditions for local wildlife. Add shade, decrease ground temperatures, maybe even help retain moisture in the soil.

    3) High voltage DC transmission can send electricity thousands of miles while maintaining acceptable losses. About 5% per 1000 miles. You can't do it with AC because such long cables have huge capacitance that makes reversing the voltage 60 times per second rather difficult. Also, there's less issues with synching the AC waveform with whoever it's connected to - local inverters do that.

    Why not simply build a nuclear powerplant closer to the consumers?
    1) NIMBY - everybody wants it but yet nobody wants it.

    2) Waste is still an issue, since the USA is scared shitless to reprocess nuclear waste (it's actually illegal in this country thanks to anti-proliferation legislation).

    =Smidge=
  • by OeLeWaPpErKe ( 412765 ) on Tuesday April 15, 2008 @10:47AM (#23077504) Homepage
    This estimate for solar power does not include transmission losses, and assumes you can losslessly transmit power from mexico to alaska (which is a location where you couldn't place this power station).

    So in practice, even today, we'd need at least 120% of the stated figure. If all in one plant we'd need 300%.

    So you need 12200 square miles for to even start.

    Note that this is already bigger than some states. Let's perhaps put this in a better perspective : this would take 0.3% (low estimate) of the surface area of the united states, 1% for the bad estimate.

    How long could one do this ? Well in 235 years the entire surface area of the United States would be necessary to generate energy (again : low estimate).

    Half of the surface area would be used in 200 years. A small table :

    Year - Area Used (low estimate) - (high estimate)
    2008 - 0.3 - 1
    2055 - 1 - 5
    2084 - 2 - 15
    2120 - 5 - 50
    2141 - 10 - 100 ... (high estimate includes a demand growth of 3.5% per year, which is the expected value if energy prices remain constant at higher demand, which is presumably what you want to do, especially since the alternative is letting people freeze)

    By contrast, energy generation by new generation nuclear power plants will last, with the large growth, over 600 years, with current technology, with thorium reactors, with negligeable surface area used. In that time, they will generate only 500 tons of problematic waste, ie. nothing we can't handle. And if we still don't have fusion power by then, well, then nobody can say we didn't give the scientists as much time as possible to study it.

    And obviously, nuclear power works in Alaska too. Alaska receives only 16% of solar energy, so to power alaska you'd need an 8x bigger solar station.
  • Re:Hmmm.. (Score:3, Informative)

    by Firethorn ( 177587 ) on Tuesday April 15, 2008 @10:51AM (#23077580) Homepage Journal
    Of course, it begs the question: How much of our current resources will it take to create/maintain these plants?

    When they say '6 to 8 cents per KWh', it generally covers construction, O&M costs. Resources generally abstract out to dollar costs.

    Basically, they generally assume you get a loan with a payoff duration of the expected lifespan of the plant. Say 20 years. They figure O&M will cost so much per year, and so many KWh will be produced. Simple division gives you O&M cost per KWh. Then you figure in the annual loan payments*. Divide and you get an expected infrastructure cost for the plant per KWh. Add the two. 6-8 cents per KWh isn't actually that bad. It'd be economical in California, for example, if not quite there for North Dakota(besides the whole 'less sun' thing).

    Let's do a bit of comparison with what I think we need more of, nuclear plants.
    $1 Billion, 1 Gigawatt plant. 90% load factor. Let's say 4% interest, plant life 40 years.
    The interest and capital will be $50 million per year. (4.18M per month)
    Random webpage [thorium.tv] says $50M for Operations
    NEI [nei.org] says 1.26 cents per KWh, including fees for eventual disposal and decommisioning.

    We can expect our plant to produce about 8B KWh a year. This translates to $100 million O&M per the NEI. I'll use this one.

    This all translates to nuclear being around 1.9 cents per KWh. In comparison, I wouldn't say that this would be economical. Even if you knock the nuclear plant down to 20 years, it only increases the cost pre KWh to 3 cents.

    *I often use a mortgage calculator that you can punch in duration, interest rate, and amount and it gives you monthly payments. It's intended for houses, but works equally well for cars and billion dollar nuclear plants. ;)
  • by OAB_X ( 818333 ) on Tuesday April 15, 2008 @11:17AM (#23077874)
    There is no one solution that is capable of completely supplanting coal.

    Yes there is, and it's been done. I point to France and it's nuclear power. The swiss use 0% coal too by using a mix of hydro and nuclear.

    Geothermal (in places where it would work, like Australia) also could replace 100% all coal fired power plants.
  • by gurps_npc ( 621217 ) on Tuesday April 15, 2008 @11:19AM (#23077912) Homepage
    As others stated, you are entirely WRONG.

    The standard plans for buildign Solar Thermal generators include heat storage devices. More importantly, in the areas where these devices are created, what almost ALWAYS happens is that during periods of peak demand, the power output is highest. I.E. During 9-5, when businesses are up and running and air conditioners are up and running , the sun is the strongest.

    Then they actually STORE up heat during the peak demand periods, to use in the lower demand period, called night.

    Using current technology, solar thermal power plants are almost cheap enough to displace fossil fuels, at least for the southern half of the country.

    I would agree that nuclear is probably going to be neccessary for the parts of the country that don't get enough sun. But geothermal is WAY too expensive, except in extremely rare locations.

  • Re:Hmmm.. (Score:2, Informative)

    by careysub ( 976506 ) on Tuesday April 15, 2008 @11:22AM (#23077952)

    Just to make something even clearer: you should read the article and learn something before recycling canned opinions.

    An essential feature of solar thermal power is that it easily and efficiently stores solar energy directly as heat. From the article:

    The key attribute of CSP is that it generates primary energy in the form of heat, which can be stored 20 to 100 times more cheaply than electricity -- and with far greater efficiency. Commercial projects have already demonstrated that CSP systems can store energy by heating oil or molten salt, which can retain the heat for hours. Ausra and other companies are working on storing the heat directly with water in the tubes, which would significantly lower cost and avoid the need for heat exchangers.
  • by B'Trey ( 111263 ) on Tuesday April 15, 2008 @11:22AM (#23077958)
    You know, sometimes it helps to RTFA. One of the specific advantages of this type of system is that the energy of the sun is not directly converted to electricity, as it is with solar cells. Rather, the energy is used in the form of heat, which in turn is used (via heating a fluid) to drive a generator. That means that you don't need to store electricity - you need to store heat so that the heat can be used to drive the generator during times when the sun is not available. The article specifically mentions using oil or molten salt to store the heat. Heat up oil or molten salt, store it in well insulated containers, and it will stay hot for a very long time. When you need it, you run the hot oil or salt through a heat exchanger, extract the heat and generate more electricity - all while the sun is on the other side of the planet.
  • Check your math (Score:2, Informative)

    by rubeng ( 1263328 ) on Tuesday April 15, 2008 @11:28AM (#23078016) Journal
    No, you'd need 8464 (92 * 92) different plants 1 square mile each. Not all parts of the country are as suitable as the desert areas are, so you'd need even more if some were going to be in the cloudier areas.
  • Re:Hmmm.. (Score:2, Informative)

    by B'Trey ( 111263 ) on Tuesday April 15, 2008 @11:30AM (#23078052)
    If you're constructing a Dyson sphere, why on Earth (HJARF!) would you bother to haul the building materials up out of Earth's gravity well? Off the top of my head, I have no idea if there's enough asteroid material to build a Dyson sphere at roughly the Earth's orbit. But there's almost certainly enough to build a Niven ring, and by the time we reach that point we could probably start dismantling the outer planets if necessary...
  • by Maxo-Texas ( 864189 ) on Tuesday April 15, 2008 @11:31AM (#23078060)
    Actually, based on some off the cuff calculations...

    Current solar acreage is probably small. A very large solar plant takes .2 sq miles.
    http://www.metaefficient.com/news/north-americas-largest-solar-electric-plant-in-switched-on.html [metaefficient.com]
    http://www.metric-conversions.org/cgi-bin/util/convert.cgi [metric-conversions.org]

    Electric Plant
    It looks like electric plants maybe about 75 acres to 170 acres.
    (various google "electric plant acres" results.
    Say 125 acres average.

    http://www.eia.doe.gov/cneaf/electricity/ipp/ipp_sum.html [doe.gov]
    350mw per plant (19,300mw/55 plants)
    604,514 = 1727 electric plants currently

    This equates to roughly 300 square miles of electrical plants currently. I'm not sure if the gov site includes dams, windfarms, and nukes. I know windfarms get pretty big (google: 40000-Acre Wind Farm (~62 sq miles), 2000 turbines over 200000 acres (~310 sq miles), Indian Mesa wind farm situated on 34000 acres in West Texas).

  • ausra (Score:4, Informative)

    by AnotherBlackHat ( 265897 ) on Tuesday April 15, 2008 @11:46AM (#23078238) Homepage
    Before reading the fine article, I thought it would be a PR piece for Ausra.

    If you read the stuff at their website, http://ausra.com/ [ausra.com], they answer a lot of the questions that have been, and doubtless will be asked here;

    It's possible to store thermal energy and use it to produce electricity at night.
    Some places do receive more sunlight than others, and plants built in those places would be more efficient.
    They have a nice PDF that shows (among other things) the normal solar radiation for different areas - plants work better in deserts than in river valleys, but there are plenty of places you can build them that are cost effective.
    Ausra isn't vaporware - they already build a plant in Australia, and they are building one in southern California.

    The current plant is cost competitive with scrubbed coal, and future plants are supposed to be on par with unscrubbed coal plants.
    That last may be hype, but at the very least they can already produce electricity for less than 12 cents a kilowatt, and cutting that in half doesn't seem unreasonable.

    Even so, at best these kinds of plants will only supplant oil and coal burning electric plants.
    We're still going to burn oil in our cars, home heaters, etc.

    Disclaimer: I am not affiliated with Ausra, but most of my information about them comes from them, or their press releases, so take it with a grain of salt.

    -- Should you believe authority without question?
  • by hador_nyc ( 903322 ) on Tuesday April 15, 2008 @12:06PM (#23078544) Homepage

    In other words, NYC is "solving" the "problem" of electricity wasted into heat (by resistance) by wasting a ton of electricity running a gigantic fucking A/C unit 24/7... which coincidentally, is just a heat pump. Is it just me, or is this really silly to start with?
    You might think so until you consider some details I didn't mention. The amount of energy wasted on cooling the superconductor is significantly less than the amount of energy lost in transmitting the power. Proper insulation does help, along with the fact that we are talking about a few limited, but VERY LARGE underground wires. In a single wire in your house, not that much power is wasted say heating up the wire that say supplies your tv with power. Touch it, it's not warm. The problem is when you try to send enough power for say Manhattan Island where you have roughly 10 million people at work during the day. Then you are sending A LOT of current, and it's the current that heats the wire. That same copper in your tv power cord ain't that good when you put a lot of power in it, and your transmission losses get huge. By cooling a special metal turning it into a superconductor, you eliminate those losses. Thus by spending a bit more energy on cooling, you save a lot more overall by using the material without resistance.

    Read up on power losses on high power transmission lines and superconductors; then you'll understand how they make sense in limited installations.

  • by geekoid ( 135745 ) <dadinportland@yah o o .com> on Tuesday April 15, 2008 @12:24PM (#23078788) Homepage Journal
    I 100s of millions , no where near trillion.
    It is actually pretty simple to build, doesn't require any new materials, and is simple to maintain.

    "More if you factor in the need to store energy overnight and on overcast days."
    It's not battery storage, it's hot liquid storage in tanks. Which is released into the turbines on demand.

    An area the size of a football field will produce 300 MWatts at the beginning. Cloudy days don't impact this things as much as you would think.
    This is NOT solar panels.

    About 5 months ago I did a lot of research into this technologies, it looks very promising.
  • Re:Buffer it (Score:3, Informative)

    by owlstead ( 636356 ) on Tuesday April 15, 2008 @02:40PM (#23080654)
    Oh, yeah, this is being researched. In the Netherlands, they are thinking about putting an island in the North sea and put a windmill park around it (usefull for damage repair as well). Now use the energy to pump out water from a big hole in the middle of the island, and use generators when you let it flow back in. Much easier and cheaper and less ugly than building a big tower. Sometimes you wonder why you don't think of things like this yourself.
  • by Masato ( 567927 ) on Tuesday April 15, 2008 @03:28PM (#23081294) Journal
    Wow... Where to start with this topic. I'm by no means an expert in the subject of power, but I have been studying it for approximately a year now (as an electrical engineer) and know people who work in the industry, etc. After reading many of the comments, I just wanted to try and clear up a few of the possible issues I see with this new source of power.

    Before I get into that though, I want to briefly discuss how power is produced today, since there seems to be a lot of misconceptions about how things seem to work.

    Power utilities today have quite a few resources to generate power. The "base load" power that everyone seems to talk about these days comes from large generation units that maintain a continuous, rated power level 24/7. The reasons for this are usually economical, but can also be based out of safety concerns for things like nuclear power. Depending on the area, the remaining power is usually generated with generation units that are committed a few days in advance (although it is possible to get a generator started from a cold start in 1-2 hours) All generators have ramp rates (the maximum amount the power can change during a given period of time), so they are unable to change their power outputs instantly. In cases where the load demanded by the consumer starts to creep above that being generated by the power plants, peaking stations (normally natural gas based) can come online and are able to respond to the load change. Natural gas, while effective at being able to keep the power generation and load in balance, is expensive, so peaking plants normally don't operate unless power prices are high or it is necessary to use them.

    If the load drops for any reason, power plants are capable of throttling down their power generation (again, subject to ramp rates) to approximately 10-20% of their rated output. Anything less than this and the unit will be forced offline (because a minimum level of stream production is necessary to turn the turbine, etc) Although this is one method of regulating power, generation units have a cost curve. The rated power is where the cost of generation is a minimum. Above and below that point, cost starts to rise, sometimes dramatically.

    Alternative resources like wind are used, but not heavily due to the nature of their power production. With modern forecasting techniques, operators are able to predict fairly accurately what wind patterns will be doing 3-5 hours in advance. The major problem occurs when the wind stops blowing. Even though we know 3-5 hours in advance that we need to generate more power, it takes a lot of effort (and money) to commit a bunch of generators to make up the shortage on such short notice. Because of this, wind power tends to only make up a small percentage of total power - so only one or two generators need to come up to make up for any shortfall.

    So what does this have to do with the current topic you ask? What the article seems to suggest is replacing the multitude of fossil fuel based generators with a few solar power generators. While this may look good on the surface, in reality there are many problems.

    The first thing that comes to mind is reliability. People take for granted just how reliable the North American power grid is. In many countries of the world (such as India), power producers cannot meet demand and must make sacrifices to various areas (usually rural) to keep the load balanced. For most modern generators, it's not unreasonable to assume a 1-2% outage rate a year. With multiple smaller generation facilities, this isn't much of a problem, since it is easy to make up the shortage by bringing another generator online. Normally, the system has "reserve power" in the form of generators that are online but not producing power. These generators must be able to start producing power in 15 minutes or less. So, if a generator fails, another generator will be brought up in its place and within an hour should be producing the full amount of required power. In the ev
  • Re:Hmmm.. (Score:2, Informative)

    by nonick ( 88963 ) on Tuesday April 15, 2008 @06:23PM (#23083230)
    Here in Spain, the energy companies are forced to buy your surplus at a cost higher than market value. I think it is pretty much the same all around Europe.

    And yet not many people install PV. (??)
  • by Rei ( 128717 ) on Tuesday April 15, 2008 @07:39PM (#23083946) Homepage
    Electrolysis isn't limited to 50% efficiency. AFAIK, some high temperature steam cells are over 85%.

    The real problem with hydrogen is that it's an utter PITA to store (i.e., expensive) and fuel cells are, and for the forseable future will be, way too expensive compared to their power output (a few kilowatts costing you tens of thousands of dollars -- and lifespan is not unlimited). In other words, the capital costs will kill you every time. There's one proposal to use the supposed "hydrogen economy" and have cars be both your storage tanks and generators. But that scenario is never going to happen; BEVs and PHEVs have already won. Lithium phosphate BEVs now can match hydrogen in terms of charge/refill time (using far cheaper infrastructure), beat it in safety, approximately match it in range per unit weight and volume (it's hard to do a direct comparison, as you're comparing kWh of storage with kW of power output in fuel cells plus the tank and fuel), blow it away in operation cost, beat it in purchase price, and blow it away in system efficiency. And battery tech is advancing a lot faster than hydrogen tech, and given what's in the lab right now, will continue to do so for a good long time. Plus, the "greens" who they expect to buy this tech by and large prefer BEVs (for the above reasons, especially the several-times-over efficiency advantage).

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