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World’s biggest solar power tower to open in Spain

By Joe Romm  

"World’s biggest solar power tower to open in Spain"


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Solar tower plant near Seville

The world’s biggest solar tower will open early this year in Spain. The race for leadership in the next generation of solar power is taking off.

The UK Guardian reports that in the desert 20 miles outside Seville, the Spanish company Abengoa will be deploying over sun-tracking 1,000 mirrors — each “about half the size of a tennis court” — to superheat water to 260C to drive a steam turbine and generate 20MW of electricity.

Concentrated solar power (CSP) technology, as it is known, is seen by many as a simpler, cheaper and more efficient way to harness the sun’s energy than other methods such as photovoltaic (PV) panels.

Spain is placing a huge bet on CSP to meet their renewable energy and carbon targets:

Spanish firms are charging ahead with CSP: more than 50 solar projects around Spain have been approved for construction by the government and, by 2015, the country will generate more than 2GW of power from CSP, comfortably exceeding current national targets. The companies are also exporting their technology to Morocco, Algeria and the US….

The country’s clean energy targets are in line with the EU’s plan to source 20% of primary energy from renewables by 2020, which means that 30% of electricity would have to come from carbon-free sources….

CSP projects across Spain are built with the promise that the government will pay a premium, known as a feed-in tariff, for any CSP electricity sent into the grid. The PS20 is part of a ‚¬1.2bn series of solar power plants based on CSP technologies including tower plants and trough-style collectors — where water is passed in tubes directly in front of parabolic mirrors that collect sunlight — and a few PV panels planned by Abengoa. The solar farm will eventually generate up to 300MW of power, enough for the 700,000 people of Seville, by 2013.

The ultimate goal is to add thermal storage to CSP and create what I think is more accurately called solar thermal baseload:

The 20MW solar tower is also a forerunner for an even more ambitious idea, one that Abascal [Abengoa's CTO] hopes will become a standard for CSP plants in future — a 50MW version that could generate electricity around the clock. “During the day, you’d use 50% of your electricity to produce electricity and 50% to heat molten salt. During the night you use the molten salt to produce electricity.”

Molten salt technology is in its early stages but Abengoa is testing the idea at a power plant in Granada. So far the company has demonstrated that it is possible to store up to eight hours of solar energy by heating tanks containing 28,000 tonnes of salt to more than 220C. “This will make it possible to have almost constant production or at least it will be able to produce energy for most of the day,” said Abascal.

Kudos to Spain for leading the way on this crucial climate solution.

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31 Responses to World’s biggest solar power tower to open in Spain

  1. Greg N says:

    Well done Spain, doing rather than just setting targets.

  2. Bob Wright says:

    This is indeed good news. 50MW (net 25) CSPs could add up fast. 40 of them would equal one or two coal fired plants. 45 or so would equal a nuke. You can put 2 nukes (2400 MW) on less than 1000 acres, but so what? The southwest desert is huge, and they would probably work in Florida. The biggest wind turbines are 3 MW, with 5MW planned, and they don’t always have enough wind. PV takes a lot of energy (and pollution) just to make the cells (that don’t add up to much of anything).

    You sure this isn’t all brine and mirrors? (Ha Ha)

  3. Dill Weed says:

    Ya ever smelt a great big ole stinkin’ turd, Bob?

    Dill Weed

  4. paulm says:

    Is this technology viable in Canada?

  5. Ronald says:

    A 20 MW plant is very small. No doubt that’s still an experimental one, they won’t build another one. Even 50 MW is relatively small. And 260 C is low, as the article says, the next ones will be with hotter temps. If I remember right, need about 600 C and 200 MW before they are at the temps and size needed for more economical full scale production.

    Can’t do this in Canada, only 4 states in the US. California, Arizona, Nevada and New Mexico. (Okay, the edges of Texas, Utah and Colorado)
    I don’t think they work in Florida.

    Here’s a link that contains a map of where this would work in North America.



  6. Rick C says:


    Concentrated Solar Power has been around since the 70′s. What is the difference between the first wave of CSP in the late 70′s and what is being proposed and implemented today.

    [JR: Multiple companies, multiple countries, multiple approaches, much lower costs, and many people pursuing storage. Plus global warming and lots of VC money.]

  7. Brooks says:

    Sounds like this could be the kind of solid success story needed to squash attempts to say renewables are too costly. But have no idea of the economics here.

    Like to never again see the word “clean” applied to coal. Just say “coal” and there won’t be that subtle suggestion that clean is even possible.

  8. Rick says:

    viable in Canada? – I’d say no – we’re just too North and dark – also cloud cover would be a killer for this. Lots of dry equatorial zones to exploit this idea I suppose.

    I had no idea dill weed was capable of such gracious and well chosen words of wisdom – live and learn.

  9. Salt means sodium chloride to most of the world. As I recall it has to be a lot hotter than 220C to melt it. What are we really talking about here?

    More importantly, once again, the whole discussion descends into cheerleading since we have no idea what this really costs. We can guess that it is not really practical since the Spanish govt. has to shove in money to prime the electricity pump.

  10. Ken B says:

    A salt is basically any crystalline ionic compound.

    “Solar Two used molten salt, a combination of 60% sodium nitrate and 40% potassium nitrate, as an energy storage medium.” So says Wikipedia, anyway.

  11. Thanks Ken B,

    The very same potassium nitrate that turns charcoal into gunpowder, makes corned beef, and dims the ardor of school boys. I think sodium nitrate is also fairly active with the right opportunity.

    That must be a bit of a challenge to handle in tanks? These should not be very expensive materials though, and of course, they do not need to get replaced.

  12. Bob Wright says:

    Hey guys. You can make brine solutions with different melting temperatures. Just get the water hotter and hotter and add the salt until it stops dissolving. Let it cool and it freezes at a certain temperature range. (A little bit of salt actually lowers the freezing point of water) The Chem E’s have charts for this and have been using brines for high temp heat transfer for years. There is a lot of energy in the phase transition, and the brine will stay near the the transition temp until all that heat is gone. Insulate the tank and most of that heat can be returned to keep the steam going. I forget if NaCl is the best salt. Certainly the cheapest.

    Even at 25 MW net, this might not take as much space as the number of wind turbines it replaces, its steady, and balancing a wind baseload has got to be nightmare.

    BTW, is Galena, Alaska going to get the 10 MW Toshiba “nuclear battery”? Toshiba digs it up and replaces it with a new one in 30 years. Cool?

  13. Bob Wallace says:

    Might want to check your saltpeter = limp weenie bit. Don’t think data has supported that one.

    Thermal storage vs. pump up hydro….

    As Europe moves to a unified grid I wonder if thermal storage will continue to be the preferred method for 24/7 power. Perhaps a few hours to extend into to late peak times would make sense, but through the late night/early morn hours it might make more economic sense to use pump up.

  14. What is the difference between the CSP in Spain and “Solar One” as described in Forbes Mag.?:”Solar One: Shut Down in 1999
    In the 1980s, the Department of Energy poured $147 million into Solar One–a plant that concentrated solar energy from 2,000 mirrors onto a 300-foot concrete tower to make steam. DOE officials called the Mojave Desert plant “a resounding success,” but partner Southern California Edison shut it down for the usual reason: It wasn’t commercially viable.”

    It looks like the one in Spain is going to have some maintenance issues with the tracking reflectors. So why is this better?

    Is there any way to get technical data on the Mojave plant?

  15. Bob Wallace, I put that saltpeter bit in just for fun.

    Bob Wright, I guess I need to dig up a Chem E guy. I think the heat of fusion is an important number to know in thinking about energy storage. If there is a Chem E guy out there, feel free to chime in.

    But Bob Wright, surely we can get past calling wind production variations a “baseload?” Isn’t the load part on the other end of things?

  16. Bob Wallace says:

    “…balancing a wind baseload has got to be nightmare.”

    I’m not sure why. We have big changes to supply/load frequently now on the grid. Having a wind farm increase or decrease its input would be no different.

    At the moment wind farms are using large flow batteries to smooth their output. Connecting farms over a wide area can mean that 70% or more of total farm output can be considered “100%” – up where hydro/coal/nuclear run.

    We’re increasing our ability to predict changes in flow from wind farms. We’re setting up wind monitoring stations some distance from farms so that the operators can prepare for an increase/decrease in wind. That sort of information can get fed tp\o grid managers in the same way that they would be informed that a coal plant is going off/coming on.

    We’re starting to install IR “look ahead” capability for abrupt changes in wind speed so that turbines can prepare for the change rather than reacting after is occurs.

    We now have natural gas turbines that can spin from stopped to full speed in 10-15 minutes. That would mean that the grid managers would need only a short warning of upcoming change in order to bring NG on line.

    We can bridge that gap with battery storage (think plugged-in personal vehicles and flow batteries) and by’smart metering’ shutting off unnecessary draws (think all the freezers in the country).

  17. Ronald Brak says:

    Canada is not the best place for solar power. However, it is possible to take advantage of natural terrain such as south facing hill sides to reduce the amount of area solar power generation would require. One thing that helps the economics of solar power is that Ontario’s peak electricity demand is in the summer during which there are many hours of daylight in Canada. But wind is a much cheaper source of low emission power in Canada and is likely to remain so for some time.

  18. Ronald Brak,

    Ontario is the only forthright state (province) entity I can find when it comes to actual data on power production.

    See http://reports.ieso.ca/public/GenOutputCapability/PUB_GenOutputCapability for Jan 2, 2009 actuals.

    Just to show how wind actually worked out today:
    WIND Total Capability 903 903 903 903 903 903 903 903 903 903 903 903 903 903 903 903 903 903 903 903 903 903 903
    Output 368 343 340 320 322 343 291 278 261 237 333 411 457 499 478 476 528 592 548 401 415 388 312

    In contrast, California seems to prefer to obfuscate.

  19. Bob Wallace says:


    Is Ontario electricity a public undertaking and thus more open/required to release data than is CA in which much of the grid is privately owned?

  20. Spain are going hard at this. They plan around 60 new plants in the near future

  21. Ronald says:

    That Forbes mag article was weird. Solar one, or solar ten before that was never meant to be commercial, it was always a test plant. That Forbes article never mentioned that and made it sound like it was meant to be a commercial electrical plant and failed; Forbes thus showing that CSP can never work. Solar one was a tower CSP and was a test site. Forbes could have discussed the 380 MW trough system that has been working in the dessert since 1986-1989? and producing electricity everyday since. But Forbes decided to only mention the test facility that was shut down after the tests were done. Selective reporting. Never believe what you read from Forbes, they have a huge bias.

    Solar ten was built in the 70′s, early 80′s to test tower CSP. It didn’t have storage and would have problems when clouds went by. So they decided to test for 3 years I think what would happen when they added salt storage. They eventurally tested it over 24 hours with storage (and more) Called it solar one for that testing.

    Tower CSP has the most potential for cost reductions, but maybe also the most risky.

  22. llewelly says:

    You can put 2 nukes (2400 MW) on less than 1000 acres, but so what?

    Bad comparison. Mining uranium is extremely land-intensive. (Thorium is slightly less land-intensive.) The solar power example contains the land area for both the fuel source and the power generation. The nuclear example contains only the land area for power generation.

  23. Bob Wallace,

    I looked up each of the Ontario power plants on the list and looked as far as possible into the details of their operation and financing. They seem to be about the same mix of private operations mixed with government funded operations like we have here in California. Maybe they have a little more hydro. Like us in CA, Ontario has government involvement in rate determination.

    This is an ongoing study but my overall tentative conclusion is that they operate according to obvious economic logic overlaid with modest public funded programs. There are some special factors relating to hydro like they have to keep tourists happy by wasting a certain amount of water over Niagara Falls.

  24. Mark Shapiro says:

    The great thing about CSP is that you could have some plants without storage (for daytime, peak use) and other plants with storage. In fact, an ideal location would have high insolation (i.e. desert southwest) and natural caverns for storage.

    It’s then a question of bringing down the cost curve.

  25. David Lewis says:

    I love the idea of CSP. But I looked into this plant today, and here is what I found.

    To start with there is this Scientific American article which states the feed in tariff subsidy may be in jeopardy in Spain. They only need to power a percentage of their grid with renewables and once they get there they might stop the tariff.


    I went to the manufacturer’s website, i.e. Abengoa


    I was curious what it would cost to build enough of these plants to replace a coal plant in the US. My calculations showed it would cost around ten times as much, capital cost. (see: further on). It still takes a Spanish feed in tariff that according to Scientific American guarantees “up to triple the market price” for the next 25 years for solar energy to get this CSP stuff off the ground in Spain.

    It seems ironic that campaigners declare that CSP solar power not only exists, but some assert it is already cheaper than coal or nuclear when Abengoa touts this 20MW plant as “the largest in the world”. I guess it could be the largest “tower” plant in the world. A pilot coal fired carbon capture (CCS) plant, the Schwarze Pumpe in Germany is running today producing 30 MW but campaigners declare that CCS, because the biggest operating plant now is that tiny, doesn’t even exist. Hey, just commenting. If you compare using capacity factor, which takes into account how many hours in a year a solar plant can run, the German CCS coal fired plant has more than four times the output as this Abengoa plant.

    Abengoa calls this plant the PS20. They have a detailed brochure for the PS10, a preceding version one half this size. I had to get some info for what follows from the PS10 brochure. Abengoa doesn’t particularly want you to know what electricity generated by one of these plants costs.

    I wanted to find out what it would cost to build enough of these PS20s to replace the 800 MW coal fired plant discussed in “American Coal Rush Hits some Hurdles”, an NPR broadcast discussing the costs of building coal fired power plants in the US. As of 2007, after a tremendous 40% increase in construction costs in 18 months due to competition from so many other coal plants being built worldwide driving up prices, plus the general commodity boom raising the price of everything back in those ancient days when the US had an economy, NPR reported that an 800 MW coal plant would cost $1.4 billion.

    This PS20 puts out 20 MW at full capacity. From the approx one half sized PS10 brochure: “with an installed capacity of 11 MW, and the local solar resource, PS10 is capable of generating 24.3 GWh of clean energy annually”. Apparently, solar power varies hourly with the angle of the Sun, the system has to be shut down when wind speed rises above 22.5 mph, the sun goes down every night, a cloud drifts by periodically, the mirrors get dusty and out of alignment, etc. 365 days 24 hours a day is 8760 hours in a year. 24.3 GWh divided by 11 MW is 2209 hours this plant could be said to be delivering power at its rated capacity. So it has a capacity factor of 25%. Other people I’m reading say actual output from CSP is less, but we’ll use this 25% derived from Abengoa’s own figures.

    Therefore it would be comparable to various other power plants depending on their capacity factor. I assumed that the PS10 and the PS20 would have similar capacity factors.

    According to various sources coal fired plant capacity factors vary between 70 and 90%. I take 75%. A new one might be expected to be better. So if I want to replace an 800 MW plant, using a capacity factor of 75%, I get 600 MW produced every hour the solar powered PS20s have to come up with to replace. 20 MW PS20s at 25% capacity factor means they can be described as putting out 5 MW every hour. So it would take 600 divided by 5 or about 120 PS20s to replace the coal plant being built in the US described by that NPR report.

    120 PS20s using Abengoa figures of 80 million Euros each, would cost 9.6 billion Euros or $13.2 billion US dollars. Hey, only almost ten times as much. (9.4 times the NPR $1.4 billion figure is $13.2 billion USD).

    Some, like Stephen Chu, say there are 150 or so coal plants at the planning stage in the US today. Industry sources say the completion percentage has been low lately due to a lot of concerns, such as what is going to be done about carbon emissions, but if 150 plants had to be replaced with Abengoa PS20s, it might cost $1.9 trillion compared to $210 billion. Now people can say carbon capture is expensive, but when the industry finally caves in and stops putting its money into “clean coal” advertising and starts spending it on CCS, they might just be able to beat $1.9 trillion, especially if no new grid is required. I’m hearing very large figures for a new grid.

    I’m not saying I don’t want solar power. I just like to know what I’m talking about. And I don’t kid myself that the bean counters looking after the widows and orphans tax dollars are going to buy whatever I’m selling: they’re going to look at the economics, and they’re going to look at the goal, i.e. keeping carbon out of the atmosphere.

    These CSP plants only have economics this favorable if they are located in favorable areas, such as Spain, or the US Southwest. Adding molten salt storage is going to increase the capacity factor and more importantly make it useful as baseload, but it seems it will also increase the cost per available MWh. If you say you need a new grid to transport this power from the Southwest throughout the US, some of that cost might have to be factored in as well. And if construction costs soar for other industries, one might think construction would tend to soar for CSP and new grids as well. I don’t know, but I don’t see some great cost reduction potential in making mirrors, and building arrays that can be aimed. It isn’t like Moore’s Law for transistors where technology made it possible to make a chip costing a few cents to replace what once took a huge building to house.

  26. Ronald,

    Thanks for talking about that Forbes article. I am not sure why they would be biased, though even still, I made my own suppositions. Probably the fact that in 1999 natural gas was very inexpensive had a lot to do with the “not economic” decision made at that time.

    If CSP can displace natural gas as a basis for electric power on a large scale, the banning of coal begins to make sense, since this banning action might not tend to drive up the price of natural gas. Of the “large scale” has to be judged on a national level.

    Like Mark Shapiro’s point, in the end it comes down to the true cost of building and operating these facilities. That is the analysis I am looking for. The technical detail would also be important to look at to get a sense of the real problems involved.

  27. David Lewis says:

    re Forbes “Biggest Energy Boondoggles”

    I tend to think the biggest energy boondoggle going is the Iraq War – I think Stiglitz costed it at in excess of $2 trillion and still rising (if you include all the future costs the US is committed to now re looking after vets etc). Part of the plan the neo cons were bragging about as they ramped up operations was it was going to create the conditions where oil prices would stabilize at $10 a barrel.

    On the topic of $2 trillion dollar blowouts: Rogoff (highly regarded economist) is saying “it would be great right now if we could write a $2 trillion dollar check and this [ the current economic crisis ] would go away…”

    $4 trillion would have been handy to have now that Hansen is wandering around telling us the NAS is ready to back him as he says there isn’t any time left for the economical phase in the new while the old wears out CO2 emission reduction plans….

  28. Bob Wallace says:

    Here’s a page that I think worth a quick look. It’s about how we could incorporate much more than 20% wind into our grid, but it applies to thermal solar as well.

    What I find especially useful in the article is the graph in the lower right (before the discussion section). It gives on a good feel of how wind and solar figure in. Clearly thermal solar with some storage could shove a lot of the NG off the page.


  29. msn nickleri says:

    Concentrated Solar Power has been around since the 70’s. What is the difference between the first wave of CSP in the late 70’s and what is being proposed and implemented today.

    [JR: Multiple companies, multiple countries, multiple approaches, much lower costs, and many people pursuing storage. Plus global warming and lots of VC money.]

  30. David Lewis says:

    I did some calculations to get a figure for how much it would cost to build enough of these Abengoa plants to replace an 800 MW coal fired power plant and my “comment is awaiting moderation” 8 days later. What’s the problem?

    [JR: If you had 2 or more links, it was put in moderation. I've had a lot of comments, so I might have missed it. I'll look for it now.]

  31. David Lewis says:

    Here is my 9 day old “comment is awaiting moderation” post again:

    [JR: It was posted a while ago.]