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Power Science

Interconnecting Wind Farms To Smooth Power Production 112

Roland Piquepaille writes "Wind power is one of the world's fastest growing electric energy sources, but as wind is intermittent, a single wind farm cannot deliver a steady amount of energy. This is why scientists at Stanford University want to connect wind farms to develop a cheaper and more reliable power source. Interconnecting wind farms with a transmission grid should reduce the power swings caused by wind variability and provide a somewhat constant and reliable electric power (or 'baseload' power) provided by other power plants."
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Interconnecting Wind Farms To Smooth Power Production

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  • Can we... (Score:5, Funny)

    by Anonymous Coward on Saturday November 24, 2007 @03:31AM (#21460975)
    Can we find some way to harness the power of Roland's blogspam?
    • Re: (Score:3, Funny)

      by OverlordQ ( 264228 )
      Yup, just attach bit turbines inline with the intertubes that deliver the World Wide Mail.
      • I always suspected a hidden meaning in Christopher Cross' 1980 prophecy, Ride Like the Wind.

        The only question in my mind now is whether Michael McDonald was in on it.
    • I'm no thermomechanical engineer, but I think spam has high entropy, and as such, is not suitable as a source of useful energy.
      • Did you even read the summary? All you need is to interconnect the spam! We could probably use some kind of TCP/IP based infrastructure...
        • Rectifiers and voltage converters could convert the re-routed spam back to useful energy. If the spam isn't located close to a distribution center, it could be transmitted via tcp/ip as the op stated.
  • WTF?? (Score:5, Informative)

    by jdray ( 645332 ) on Saturday November 24, 2007 @03:39AM (#21461001) Homepage Journal
    If I read the article right, this guy has no clue what he's talking about, or is completely misinformed. What does he think the national electrical grid does? The only thing that making an entirely separate distribution grid for wind power would achieve is to ensure that the power being delivered to a particular point was 100% wind-generated. As soon as it enters the common grid, though, it's mixed with "brown power" (fossil fuel generated, as opposed to "green power"). Unless municipalities want to run entirely from one source (no reliability to speak of), this is a useless and horribly expensive exercise.

    Just to qualify, I have nearly a decade of experience in the energy industry, specifically electric. Right now I work for a wind power company.
    • by QuantumG ( 50515 )
      If there's low demand when there's high supply of power (any kind) then that power is lost. There's no storage. That's the issue that needs to be solved. Of course it makes virtually no difference right now cause there's almost always enough demand to use all the available supply of wind power.

    • Re:WTF?? (Score:5, Funny)

      by dbIII ( 701233 ) on Saturday November 24, 2007 @03:53AM (#21461057)

      If I read the article right, this guy has no clue what he's talking about, or is completely misinformed. What does he think the national electrical grid does?

      We are talking about Roland here - a lot of his stuff is "just heard about something obvious - got it wrong slightly and just have to enthusiasticly share it with you."

    • Even then, we just pump the wind power into the grid and ask people on the tail-end to pay for the wind power. This is what Colorado does. The wind is added to the grid, and the extra cost gets dished out to people who pay for the wind generated energy. In the end it is the same result. Although, a year or so back the wind power dropped below the "brown power" and the program was pretty much capped at that point.

      You don't need to have any experience to understand the power grid at the level of pump power in
    • Re:WTF?? (Score:4, Interesting)

      by niceone ( 992278 ) * on Saturday November 24, 2007 @04:24AM (#21461173) Journal
      I think the point is that these Stanford guys measured the wind at a bunch of places across the midwest and then figured out how much power could be generated by the aggregation of these places. Then you can use the this data to decide a national policy and to provision the long-distance capacity to get this to where to consumers are - the example they give is California. As for the the national power grid being used - I was under the impression that the US did not have a national power grid with enough capacity to move significant power around. Isn't that why there can be shortages in California while everyone else is fine?
      • Re:WTF?? (Score:4, Informative)

        by jacquesm ( 154384 ) < minus physicist> on Saturday November 24, 2007 @05:27AM (#21461333) Homepage
        the shortages in California that have been on record were during the Enron period, look for the movie 'Enron, the smartest boys in the room' using your favourite bit torrent site for more info. The short version is that those outages where engineered to drive up the price of energy.
        • Re:Homework (Score:5, Informative)

          by Technician ( 215283 ) on Saturday November 24, 2007 @12:38PM (#21463157)
          The short version is that those outages where engineered to drive up the price of energy.

          The long version is they were able to do it because there was not enough transmission capacity to import the power to replace the spike in demand from the heat wave and the shortage of online generation capacity.

          Enrron was fighting price caps. It was done by selecting an upcoming period of increased demand as a time to shut down several plants for maintenance knowing the transmission infrastructure couldn't carry the load. They were hoping to use the shortage to force their hand. They pushed higher prices to ensure increased generation capacity. It fell apart when the books were examined. Somehow they didn't see that one coming.

          look for the movie 'Enron
          That's the Hollywood version. They take some facts and then add scriptwriters to make a drams out of it. Often the facts are ignored to make a good drama even though the movie is based on a true story. The movie doesn't have time to educate the moviegoers into the VA limitations of transmission lines, the problems with high power factor loads such as air conditioning putting additional reactive power components on the line. (How many times was MegaVars mentioned?) I'll have to watch the movie just to see if they even mention the Volt-Ampers capacity of the line. I wonder if they simply mention Mega Watts and ignore Power Factor.

          The delivery capacity is real. The GP was right. The parent missed some simple homework. Here is a couple items on the capacity issue.

          "The Federal Energy Regulatory Commission, the agency that oversees transmission, has been trying for years to prod power companies into forming new, multi-state regional grids with authority over planning and system reliability measures. But utilities in the Southeast and Northwest fear that a more wide-open system would allow their cheaper power to be siphoned away from their customers. They have made war on FERC's plans and some members of Congress are trying to block the commission's transmission initiative from going forward until 2005 or 2007."

          "The Path 15 upgrade in California represents the first public-private partnership organized to improve a transmission system that has become seriously congested. Pointing out that Path 15 is not the only circuit that has suffered from congestion problems, the Electric Power Research Institute (EPRI; Palo Alto, California, U.S.), estimates that US$100 billion must be spent to upgrade the U.S. electricity grid."

          "When the lights went out in Northern California in 2000-2001, a long-standing transmission bottleneck received national attention. A contributing factor to the crisis was a transmission constraint in Central California known as Path 15, where three 500-kV lines linking northern and southern California narrowed to two lines for 84 miles (135 km) through the Central Valley. The corridor's lack of transfer capacity hampered efforts to move available generation north from southern California and the desert southwest."

          California may have enough Santa Anna winds to localy provide much wind power, but in the dog days of summer, the transmission system is not up to the task of importing sufficient power from out of state.

          "By late 1998, load growth had become a significant factor for grid operators, who were prevented from moving power across the congested Path 15. The congestion hit hard in 2000 and 2001 when scarce generation forced the ISO to declare stage-three emergencies, indicating reserves were so low that rolling blackouts were imminent and resulting in several days of rotating outages of firm customer load. The emergencies extended into the winter with threats of outages continuing. Between Sept. 1, 1999, and Dec. 31, 2000, consumers spent an
        • In my other reply, I mentioned that Hollywood would have taken liberties with the truth to make a drama. I have never seen the film, but I know Hollywood.

          Even after the Clintons left office, they kept the pressure on. When the Enron collapse seemed imminent in November 2001, Robert Rubin called a senior Treasury Department official in the Bush administration and asked him to discourage the bond-rating agencies from downgrading Enron's debt. The Bush Treasury Department refused to intervene on Enron's behal
      • by khallow ( 566160 )

        The California energy crisis was due to the breakdown of their privatization effort. New electricity generation was prohibited in the state (for a ten year or so period) while all three big electricity providers were by the end selling electricity at a low fixed rate (so no incentive for customers to reduce demand) while forced buying power at market rates. Enron and other companies engaged in a number of price fixing strategies (including taking power generation offline) which worked extremely well due to

      • I was under the impression that the US did not have a national power grid with enough capacity to move significant power around
        I'm not sure what you mean by capacity to move it around - doesn't electricity just loose strength over long distances unless the wires are made of pure gold or silver or somesuch? I don't think it's possible to move electricity from, say, New York to Los Angeles without an affordable outdoor-temperature superconductor.
        • I'm not sure what you mean by capacity to move it around - doesn't electricity just loose strength over long distances unless the wires are made of pure gold or silver or somesuch?

          Power transmission over long distance is a science. If you take a course in circuit fundamentals and learn Ohm's law, you can calculate the power lost in a transmission system. All wire has resistance.. True. Current in the wire converts some power to heat making the wire warmer.. True. How much is lost?? That is the time to
      • by kenh ( 9056 )
        Yay! The Eco movement meets NIMBY on a grand scale!

        I want my power to be from wind mills, but don't litter my pristine mountain ranges with those silly propellers - instead there is all this land in the middle of the country that we could put them on. Of course, minor details like power line transmission loss pale in comparison to the smugness they can claim by having 100% wind power.

        These pin heads could have the net same effect if they were to move 100% of all internet data centers to the middle of the co
    • by Xman ( 100370 )
      As an added bonus, the paper seems to ignore the fact that it's damn hard to get the right-of-ways required to build Transmission, let alone this goofy-just-for-wind transmission system.

      Consider this story [] about wind farm projects in trouble because the Transmission they need is only justifiable if a base-load Coal plant is built nearby.

      Everyone wants to go to heaven, but nobody wants to die.
    • Sine you work for a wind company, then you should know that the grid is really lacking. In particular, we have very large lines from powerplants into cities. Make sense since our approach for multiple decades was one of single point of supply to roughly single point of delivery. In between these points, the grid thins out. What is needed is for an increase in capacity in between these. In particular, we are making somehead way with superconductors. The manufactuering is still expensive, but a line across th
      • by jdray ( 645332 )
        I do know that the grid is lacking. That doesn't mean it makes sense to build a second grid alongside the first to carry just wind power. That's just silly.
        • Mostly You're right of course.

          The better defense of a dedicated line, is that long-haul lines are non-standard. High Voltage DC for example is not your average grid, and it makes sense to run long-haul transmission right next to local 60hz service because of the efficiency gains. Stanford may be proposing that HVDC interconnects between Windfarms are cost justified. Perhaps they also serve as seasonal load redistribution as well, so they are not exclusively "wind-only", but if the end points are say a wind
    • If I read the article right, this guy has no clue what he's talking about, or is completely misinformed.

      Based on the summary, I tend to agree (couldn't get to the article for some reason). However, it does occur to me that if a supplier can provide easier-to-schedule wind output, which the kind of "smoothing" the article discusses might be able to provide, then perhaps there's some economic incentive for this. I agree there's no incentive from an engineering standpoint, but we all know that that isn't the

    • You're correct, the author of said article is on crack. Just hooking up your wind farm into the power grid somewhere should be sufficient.
    • I would like to know how to synchronize the frequencies that different windmill farms would have on the grid. There would be tremendous power surges if Farm A was a fraction to one half cycle out of synchronisation with Farm B. When you build a grid, there will be more than two Windmill Farms involved, and therefore the problem, as I see it, becomes a (N-1) squared one.

      Perhaps the way to do it is to have one central source with a fixed frequency to serve as a reference and from which each Farm must advan

      • by jdray ( 645332 )
        The transmission system ("the grid") has voltage and frequency regulation systems built into it. Indeed, transmission service providers (the owners and operators of transmission lines) provide those services, along with others, under a cafeteria-style heading of "ancillary services."
    • by mpe ( 36238 )
      The only thing that making an entirely separate distribution grid for wind power would achieve is to ensure that the power being delivered to a particular point was 100% wind-generated. As soon as it enters the common grid, though, it's mixed with "brown power" (fossil fuel generated, as opposed to "green power").

      Building a power grid exclusivly for wind power isn't that "green" anyway. Sooner or later you will simply be duplicating existing power lines for no good reason.
  • by hoggy ( 10971 ) on Saturday November 24, 2007 @03:41AM (#21461009) Homepage Journal
    If only there were some kind of existing infrastructure to do this! A kind of grid that runs nationally and can be connected to by different power generation systems. Even better, what if you used the same grid to distribute power to those using it!

    Think of the possibilities!
  • I think they'd better patent this.
  • by mrbill1234 ( 715607 ) on Saturday November 24, 2007 @04:21AM (#21461163)
    Wow a Beowulf cluster!
  • by Animats ( 122034 ) on Saturday November 24, 2007 @04:30AM (#21461197) Homepage

    It's Roland the Plogger again, trying to drive traffic to his blog. It's not like he actually understands what he posts.

    Here's the actual paper, Supplying Baseload Power and Reducing Transmission Requirements by Interconnecting Wind Farms []. The authors have been crunching on wind speed data to try to figure out if a widespread enough set of wind farms would statistically be able to consistently produce power.

    Their definition of "consistently produces power" is 79% to 92% uptime. This figure is based on the uptime for a typical single coal-fired generation unit. But they're using those numbers for a whole collection of widely distributed wind farms. That's not an appropriate comparison.

    They have some moderately encouraging numbers for a set of 19 wind farms spread across a thousand kilometers, from New Mexico to Kansas. But look at Figure 3. 92% of the time, at least a quarter of average output is available. The output reliably available 99+% of the time is near zero.

    What this paper actually demonstrates is that "baseload wind" isn't going to consistently provide power, even with a big grid. You need peaking plants or energy storage.

    • by WoTG ( 610710 ) on Saturday November 24, 2007 @05:14AM (#21461301) Homepage Journal
      It's been mentioned a few times around these parts, British Columbia, that our primarily hydroelectric dam power generation system is a great match for unreliable power generated by wind (and solar). For the most part, hydro dams can literally be turned on and off (and many levels in between) quickly.

      The same can not be said about nuclear. I'm not sure, but I think coal and other fossil fuel power plants are not efficient at dynamic adjustments either.
      • Re: (Score:2, Interesting)

        by pesho ( 843750 )
        I was thinking the same thing. In my country (Bulgaria) the nuclear power plant(s) were planed in combination with cascades of hydro dams. The idea was to use excess power during the night time to pump water from the lower dams to the upper dams, turning them both into water and energy storage. If there was need for more power during the day the hydro dams would supply it and the water will be held in the lower reservoirs. I don't see why this can't be applied to wind and solar power.
      • Re: (Score:3, Interesting)

        by jcaplan ( 56979 )
        Nice point about management of power from dams. It got me thinking about power management in general. We can manage load in three ways: managing supply, storing power and managing demand.

        Managing supply can be done by carefully choosing when to turn on and off various sources. As the parent mentioned, nuclear, coal and fuel oil are not well-suited for rapid adjustments to power to respond to demand variation and used for base load. I was going to tell you that gas-fired pants did not fall into this categ
    • Actually you have not quite got it. Continent scale wind can provide 60% of demand before you have to figure out what to do with excess generation: [].

      It is your concepts of baseload and peak which are hindering your thinking. It is obvious that wind is forecastable and has slow variations in availability when many regions are connected. Thus, fuel based plants such as coal plants can be used as infrequent additions to the system
  • This is semi related, but recently on a few trips to Orange County / John Wayne airport from Dallas, we flew over what must have been 500 miles of wind farms in west texas (maybe new mexico?)

    Does anyone have any more info? It stretched all the way as far as I could see from the airplane, and we flew for about 45 minutes before they stopped... it's insane.
    • Re: (Score:1, Informative)

      by Anonymous Coward
      See also my point #5 below that addresses the original slashdot post about scaling/aggregating wind farm output (T. Boone Pickens).

      Here is some more info:
      1. Texas is the largest wind power producer in the world, now exceeding California and all other countries.
      2. western Texas has the majority of Texas wind power, but there is some developing along the 1400 mile coast line as well

      3. Texas is the leading state for power deregulation, including a crucial but little-known piece of deregulation that permits a p
  • Is there some way I can filter out the articles submitted by roland? I never want to see another one. If that is not possible can I filter Zonk?
    • second that.
      and while we're at it can we get rid of the 'you have to wait this long before you can reply' requirement. I type fast and I'm sick and tired of having that thrown at me.
  • flexible consumption (Score:3, Interesting)

    by spectrokid ( 660550 ) on Saturday November 24, 2007 @04:44AM (#21461231) Homepage
    Transporting electricity over long distances is expensive. There are better solutions. Deep-freeze warehouses can drop their temperature when there is a lot of wind and then turn off the coolers when there isn't. In Esbjerg (DK) they have both windmills and distributed central heating (small power plant uses exhaust to heat houses). When there is a lot of wind, people turn on their central heating and the power plant has to generate a lot of electricity to be able to supply all those houses with exhaust heat. With the windmills running full power, the price of electricity drops to zero. Now you can transport all that power to Poland, or you can tell some of those Esbjerg houses to switch to electric heating. What do you think is cheapest?
    • Remote power systems (dams) in South America are sometimes supplied with a companion aluminum plant to convert the energy into a high value commodity. The raw material comes in by rail and the finished product and the stored energy leaves the same way. No 1500 mile power lines needed, good efficiency and nobody complains about the pollution.
  • the guy is clueless.

    the biggest factor in matching wind power to the grid is not interconnecting them, the grid does that just fine, but stabilizing power output, and there are some pretty impressive solutions out there involving superconductors. Another problem is that wind power is traditionally generated best where there are by pure coincidence *no* transmission lines at all.

    To offset demand you simply need overcapacity, interconnections are obvious, if the power is not brought to the grid you might as w
    • Not sure what physical grid he's talking about. But there is a model of distributed micro generation where you leave the actual power at the location of generation, but ship the savings over the internet. it would mean that you would "undersize" the micro powerplants (so there's little excess to supply to the power grid, but at least they're cheaper powerplants to install) and always shave a fraction off a household's grid demand, in an asymmetric, intermittent fashion. that is: at one location, some days i
      • I've lived off the grid in canada for 2 years, and in my experience if you are careful about your useage you can get by with surprisingly little input power. We used wood heat for all heating purposes, about 1700 watts of solar and a 2KW wind turbine. With that combination the generator was used once every 2 months or so to equalize the batteries. We did the laundry in the community laundry hall.
        The total cost of the system was quite substantial but the experience alone is priceless.
        The golden rule of homep
  • There are two incorrect assumptions in this discussion: a) that we have to make generation fit usage, not the reverse, and b) that we don't know what the wind is going to be doing in a few hours time.

    a) Many industries could use power when available, not on demand. Desalination is a great example. The problem is that energy delivery and markets are not structured to work this way. Yet.

    b) With short-term prediction of hours to days, you can master the variability by scheduling conventional generation around
  • moderation of both people who post and the editor how allow people like RP to post just so they can generate trafic.

    I am not sure wether this posting will be moderated insightfull, off-topic or whatever, but at least people have an option to do it. Unfortunatly this is not possible with the obvious abusers.
  • Perhaps we could use cow farts to power turbines...
  • Lemme see... what if we look at the net energy produced? Adding all those towers and wires, it must take quite a bit of energy to refine all that steel and aluminum. How long do the windmills have to turn to make up for all that energy? Until then you're in an energy hole.
    • Actually, only about half a year. see: []

      Several studies
      have looked at this question over the years and have concluded that wind energy has one of
      the shortest energy payback times of any energy technology. A wind turbine typically takes
      only a few months (3-8, depending on the average wind speed at its site) to "pay back" the
      energy needed for its fabrication, installation, operation, and retirement.

      • Actually, [windmills take] only about half a year [to pay back the energy cost of making them - mainly making their aluminum towers].

        Also: The energy output of windmills is high-quality electricity (i.e. the output end of the carnot cycle) but much of the energy of construction is heat. Comparing the two is apples-to-oranges.

        On a related note: Solar panels take longer to repay the energy cost. But they are used primarily to provide off-grid power. So they need to be compared to the energy cost of insta
  • It's a bit like having a bunch of hamsters generating your power, each in a separate cage with a treadmill. At any given time, some hamsters will be sleeping or eating and some will be running on their treadmill. If you have only one hamster, the treadmill is either turning or it isn't, so the power's either on or off. With two hamsters, the odds are better that one will be on a treadmill at any given point in time and your chances of running, say, your blender, go up. Get enough hamsters together and the o
  • When you see a hamster analogy, you just know your dealing with quality journalism.
  • You know, to generate wind so the wind generators will always be running.
  • Understand it. Having to haul High Voltage AC over 3,000 miles is not ideal. Having to build out (and acquire property for) new point-to-point HVDC lines is crazy expensive. Local, decentralized, regionally grid-tied for backup.

    And for those mocking methane and cow flatulence above, there's a 5.66 megawatt power plant running from landfill decomposition gasses in Oregon (since 2005, actually). Seems financially viable, as they just expanded it. []
  • Wind power is always colloquially expensive which is why it makes up such a tiny portion of power production. Even in Norway where they claim 20% that's only capacity factor not actual energy production. The multi billion euro program has them at 6%. One of the biggest problems with wind is it destabalizes the grid so horribly badly and connecting a lot of wind turbines is not going to provide the reliability grid operators require. The only way it works reliably is to send the energy to pumped storag
  • I'm constantly amazed by how poorly U.S. citizens are served by their infrastructure. The free market is unable to provide adequate service for society without a government strong enough to impose common-sense demands and limitations.

    Nothing in that article is not obvious. None of the 'solutions' will solve any of the problems; connecting wind farms together to make more use of existing transmission systems requires (you've guessed it) more transmission systems and could well overload the existing systems

With all the fancy scientists in the world, why can't they just once build a nuclear balm?