Wind: still enough to save the world 14

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1. 

   veritone Posted 8:45 am
   30 Jul 2009

   This is good news indeed and I applaud you for drawing attention to it. I'm sure, however, you also know, that because of wind's intermittency, that growth of wind energy doesn't completely de-couple us from conventional, and far more polluting, energy generating sources -- at least for now. If, however, we also make huge committments to curtailing overall energy use, while exploring opportunities for energy efficiency, then we might start moving in the right direction. I mention all this as an anti-dote to what William Catton Jr. refers to as "Cargoism," the belief that technology will always save us. And let me be very clear that I'm not accusing you or wind enthusiasts of engaging in cargoism. As I said at the outset, this is good news.

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2. 

   Gar Lipow Posted 12:59 pm
   30 Jul 2009

   Hi Veritone. It is better news than you might think. While wind in any one place is intermittent, it becomes less intermittent when you attach a lot of wind farms together in distant places with high voltage direct current transmission lines.  This does not turn wind into baseload. (Actually not strictly true . It turns a minority of power generated into baseload.)  But it generally reduces the length of time wind power is "short" compared to a baseload target to hours rather than days. And what this accomplishes is that you can add a comparatively small amount of storage and end with wind being able to supply 70% to 80% of reliable grid. If you overbuild to compensate for seasonal variations it can do better than that - 90% to 95%. I'm on the way out so will post links to support this later. I will add that in practice we would use more varied power sources than this for the sake of reliablity and to minimize costs.

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3. 

   so left i am right Posted 6:02 am
   31 Jul 2009

    Sounds great on paper, or on screen. In theory this is possible but I hate to rain on anyones parade... to build that kind of quantity of wind power would require more raw material resources than we may have available period. Steel, fiberglass (okay that’s not natural), copper aluminum, etc lots and lots of raw materials. Plus the energy used to manufacture, transport, install and lets not forget maintain these green producers is far from green and possibly more energy intensive than the energy we’d get from them!    If you add up all the “energy” used to extract, transport and refine the raw materials, manufacture the units, transport and install them adding in some replacement parts and maintenance - wind comes out just barley positive in EROEI (energy return on energy invested) or “net energy.”   Of course you can’t predict the wind so when city A wakes up and millions starts the toaster toasting on a windless day well... that’s going to cause a circuit to fail and down goes the hole system. Electricity loss in transmission is more than 50%. So to send power to windless areas would require building more than twice the generating capacity in gusty parts of the world.   Please don’t get me wrong, I’ve been advocating for alternative energy since the 70’s! I just don’t see anything/all we can do adding up to be equal to what we use today in fossil fuels. The only possible solution I see is a massive fall back in lifestyle for the industrial world. So massive that no one will ever go for it and as such - it wont happen. That’s the political obstacle, yes. 

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4. 

   Sean Casten Posted 7:11 am
   31 Jul 2009

   I agree with Veritone.  As a capacity resource, wind nationally doesn't provide much more than 6 - 7% of it's nameplate.  In other words, for every 1,000 kW of wind turbines installed, you can only statistically count on 60 - 70 kW to be available at peak demand.  Up to a point, that doesn't matter any more than it matters that I can't count on you to turn your lights on and off at a certain time; the balance of the supply on the grid can handle the swings.  But once the volume of the wind relative to total generation exceeds a certain threshold, system planners immediately start operating other generation differently.  In the Northwest, there is hydro being curtailed on a regular basis right now so that it can "surge" when wind output drops.  (e.g., we're minimizing use of one renewable to facilitate the use of another).  In parts of the midwest, we're running fossil plants on hot standby (e.g., we burn fuel, but don't make power) to serve the same purpose.In theory, could you get rid of all that standby need by building massive, high-voltage transmission networks and storage facilities?  Sure.  But in theory, we can solve population pressures by colonizing Mars.  At some point, economics comes into play, and that's a damned expensive solution.Bottom line here is not that wind is universally bad, but simply to acknowledge that it's not universally good either.  Stick 1,000 MW worth of wind in any given node on the grid and you're probably not going to notice (since any given node has about that much spinning reserve anyway).  Get above that level and the benefits of incremental wind diminish. 

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5. 

   Gar Lipow Posted 12:09 pm
   31 Jul 2009

   SoLeft: EROEI on wind has been documented as a lot more than "barely positive".  A compilation of studies on Energy return on energy investment in the Encyclopedia of Earth shows the average result for  payback at around 18 to 1 which is better than the EROEI on oil drilling. (Yes there the list includes longer payback (though most of those are from older studies done on smaller more primitive turbines). But some of those studies also show shorter pays include energy out to energy in ratios of more than 70. Averaging multiple studies is a recognized method of coming up with a valid meta-estimate is these cases. Veritone:What about intermittency? Archer & Jacobson's "Supplying baseload power and reducing
   transmissions requirements by interconnecting wind farms" studied the effects of interconnecting wind farms. This showed at  at least 33% and as much as 47% of power produced from such interconnected farms could be used to provide reliable baseload power.  This is *without* storage. The point here is that when one wind turbine is producing little or no power another will be producing a great deal.  So you can get baseload capacity  of 33% to 47% of average capacity (which is 35% to 40%).  However a survey of wind patterns done for a V2G study shows that a 70% of "low wind" periods for such an intereconnected set of wind farms last 3 hours or less, that a large minority are 9 hours or less, and that an overwhelming majority are 11 hours or less. So a comparatively small amount of storage could turn wind into a truly reliable source of a large percent of power. Mix in a solar thermal electricity which is complementary to wind. (Sun tends to be strong during time wind is weak.) Add a small amount of hydro and geothermal (say 2% to 5% of total grid) for daily shaping to reduce storage needs. Add cheap natural gas turnbines to use as backup when everything else fails (1% to 2% of kWh over the year, but a much higher pecent of capacity. But capital costs for natural gas turbines are low, especially if you use 40% to 50% efficient turbines rather than the more expenisve 55% to 60% efficient ones.  It is operating costs that are high for natural gas. So if they are providing a small percent of the total, they remain a cheap backup.)

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6. 

   Gar Lipow Posted 12:39 pm
   31 Jul 2009

   Sean, typically new (as opposed to older less efficient) wind turbines average 35% to 40% of capacity. Even older ones averaged 29% unless you go really far back.  In terms of "curtailment" of hydro, hydro represents 25% of nationwide nameplate capacity but around 3-5% of kWh generated.  Hydro, other than exceptional cases like Seattle where it represents 100% of power, is used for peaking and load following more than baseload.   So using hydro to shape wind shifts when it is consumed rather the decreasing total amount consumed. If we put really large scale wind into place, communties that run on a 100% hydro now would use some of that hydro to shape some of their own wind power and solar (or to shape imported wind & solar if they lacked that capacity locally) and export any they did not need for that purposes to other communties that lacked sufficient resource for this shaping. In a  95% wind/solar scenario, we would combine the use of long distance transmission, hydro and geothermal for shaping, storage for additional shaping and for peaking and load following, and small amounts of fossil fuel for backup. In terms of "hot burn". I will note some of that was going on before wind came along, and that an hour or two of storage can help elimanate the need for "hot burn" by providing lead time ramp up from a cold start. (If a plant can't be brough on-line in two hours from a cold start, that is a good argument for replacing it with something else.)

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7. 

   Sean Casten Posted 2:06 pm
   31 Jul 2009

   Gar,I think we're mixing terms - allow me to be more precise.  I agree with you on the 35 - 40% of nameplate capacity for the turbine itself.  I am referring to capacity on the grid as a whole.  Utilities (or system operators in restructured states) have an obligation to ensure that they have generation contracted to provide peak demand on the system.  This system capacity obligation must be met through utility-owned assets and/or contracted power supplies from third parties.  This is the 6 - 7% figure I was referring to.  Suppose you are a utility manager responsible for 10,000 MW of peak load and someone comes along with a 100 MW wind turbine installation.  How many additional MW do you have to procure to ensure that you can meet your 10,000 MW obligations?  It's not the capacity factor of the turbine specifically that drives that calculation, but rather the probablisitc likelihood that those 100 MW will be available during the moment when you have to serve 10,000 MW of demand (in utility-jargon, this is referred to as the "coincident peak".)  What utility managers have found is that this coincident peak is 6 - 7% of wind turbine nameplate, so that the answer to the question posed above is something like 9,993 MW.  (10,000 - 7% of 100 MW).  To be sure, they now have 93 MW that doesn't have to run whenever the wind turbines are running.  But they do have to be available to run, which means - to the extent that it is fossil-fired generator, as it is in much of the country - they are kept on hot standby, burning fuel to keep hot so that they can come on line instantaneously, and emitting CO2 while they're at it.  An honest assessment of the environmental impacts of wind has to take this CO2 into account, at least in those parts of the country where the marginal unit of wind is requiring the utility to procure a marginal unit of hot standby.Re: hydro, I'm not sure I agree that it is there for peaking, but do agree with your national and regional point about it's relative importance as well as it's implicit storage ability.  I raised it only because this is the best possible scenario for the provision of wind capacity backup, since at least we're not burning additional fuel.  It's also quite real - friends at BPA have told me that they keep as much as 700 MW of hydro held back today that they didn't keep held back 10 years ago solely to accomodate the swings they've observed on the system due to wind.  In places like the NW where the hydro resource is sufficiently large to accomodate, that's great.  But in the windy parts of the NW, that spinning reserve is being supplied by burning coal for hot standby.  That's bad.And again, it doesn't mean that wind is bad - only that (like any other resource) it needs to be right-sized on the system.  An important part of the whole, but not a universal solution.

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8. 

   Gar Lipow Posted 7:20 am
   01 Aug 2009

   I did not say hydro is *only* peaking, but a lot is used for peaking and load following. That is why hydro is around 25% of name plate capacity but around 4% of actual supplied kWh.  If we start using a lot of wind, the key will be to NOT use coal as spinning reserves. Put on line a lot geothermal, and distribute that and existing hydro more widely.  Use storage, and use single cycle natural gas turbines, which are not particularly efficient, but can be brought on line in a matter of minutes. Or use some of the new generation of combined cycle turbines, in which the gas turbine is brought on line in under ten minutes, and the steam generators then gradually come up, bringing it up to full combine cycle load in under 45 minutes.Note that the advanced model is only worth it if natural gas is providing more than a percent or so of total power. This is an example of what Amory Lovins calls "tunneling through the cost barrier".  If variable renewables provide 20% or 30% of total power then whatever "shapes" that wind/solar power will run a great deal of the time and needs to be efficient. But if you have a mostly renewable grid, wind and sun shaped by hydro and geothermal and a small amount of storage, then you can get by with a really small amount of natural gas as a percent of total power. Mostly wind and sun, with a bit of natural gas will probably be cheaper than a substantial amount of wind and sun combined with a substantial amound of natural gas. The low ends of the cost curve are at the extremes - a tiny bit of renewable energy or a great honkin huge percent of renewable energy. A *moderate* amount of renewable energy is more expensive than either.

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9. 

   Sean Casten Posted 6:23 am
   03 Aug 2009

   Gar,My point on storage + transmission as a solution to renewables is that it presumes that the cost doesn't matter.  Those require massive investments, to the extent that a reasonable question has to be asked whether such investments are in the national interest.  Moreover, in the interim, one has to ask the unintended consequence question: so long as transmission + storage isn't there, more wind = more CO2 in those parts of the country where wind has reached sufficient pentration that further accomodation requires more (fossil fired, in the current architecture) spinning reserve.  We certainly agree that it would be good not to use coal as spinning reserve.  The reason it happens today is that in the coal-dominated parts of the country (which is also much of the wind-rich areas), maintaining voltage support requires pulling on a coal-fired generator, as there isn't enough lower-carbon gas capacity available.  Moreover, it's the really sh*tty, inefficient coal that serves this function, as it's not economic to justify using in any other cycle.  It would be nice if that weren't the case, but until we build new capital - be it storage, wires, or some other new spinning reserve plant - that's the stuff we will run, and need to factor those environmental consequences into wind planning.The truth that has to be confronted is that wires and transmission are really, really expensive.  Maybe they are our cheapest solution (although I rather doubt it).  But the fact that they could work in theory doesn't mean that they are optimal.  In theory, if I was a leprechaun, I could make pots of gold appear.  But that doesn't mean I shouldn't keep going to work in the meantime!  : )

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10. 

    Sean Casten Posted 10:42 am
    03 Aug 2009

    Gar:Here's a good graphic showing the coincident peak challenges from wind @ BPA (in real time).

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11. 

    Gar Lipow Posted 10:13 pm
    03 Aug 2009

    Partly you are divierting the discussion. The (very short) original post was about what was physically possible and feasible in the sense that it could be done, for example, less expensive than nuclear energy. That is not the end of the discussion, because it does not settle the question of what is optimum,  or what is politically possible, but it is a precondition for serious discussion about those questions. So the point is that we could replace all our electricity with wind plus transmission plus storage combined with existing hydro, feasible geothermal and a few percent natural gas.  Now to get optimum results we put more efficiency in  mix (including recycled energy) maybe some biomass (but probably not much), solar thermal electricity(probably a lot), PV and so on. And we can argue about what the mix is. But it is absurd to argue that a constraint on how to phase out emissions is  that it has to be compatible with using existing coal plants in as efficient a manner as possible. Hansen and most climate scientists who look at the solutions end agree that phasing out emissions equal to existing coal over the next decade is the minimum that has any chance of averting complete catastrophe. Now maybe that cut won't be done completely in the form of eliminating coal, but it seems foolish to assume that we should not consider this. Any solution will require doing stuff we are not doing now.
    As to your leprechaun analogy is I'm afraid stupid rather than silly.  You can't become a leprechaun, but we can build long distance transmission and storage.  More and more climate scientists are agreeing we need an 80% reduction or more in emissions over the next 20 years. I'm happy to debate what the best means of doing this, but I'm pretty sure that will include shutting down coal plants. You don't think that is feasible? Then, just within the U.S. , we  need to start thinking about how we deal with a drastic reduction in our ability to grow food, how we deal in ten or fifteen years with internal refugee crisis many times the size of the Katrina displacement, how our healthcare system will cope with a major increase in diseases. And worldwide the problem will be much worse.

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12. 

    Sean Casten Posted 5:42 am
    04 Aug 2009

    Gar,I don't set out to change the discussion, but to keep it grounded in realism.  Thus my leprechaun analogy.  Wind is not a panacea any more than nuclear is a panacea, biomass is a panacea or recycled energy is a panacea.  All have a role to play, and it is possible to overdose on any of them.  The fact that you can "solve" wind's problems with massive investments and T&D and storage is essentially a damn-the-torpedos, costs-don't-matter argument.  If there's no cheaper way to deliver an equivalent reduction in CO2, I accept the argument.  But that's pretty shaky ground to argue from. By all means, let's use deploy wind up to the point that it isn't causing voltage stability / capacity provision problems on the grid that require us (in the short term) to adopt cures that are worse than the disease.  Above that point, let's look to other technologies to play their own niche roles, and by all means, let's continue R&D efforts to see if we can increase the theoretical limits on any and all of those technologies.  But let's not suggest that the only constraint on our ability to realize the environmental benefits of wind is building the turbines. 

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13. 

    nofreewind Posted 7:28 pm
    17 Aug 2009

    Interconnecting wind farms to supply a steady supply of wind?  You are kidding right?  This might??? work for one county somewhere, but I don't think you have any idea how many wind turbines this would take. I live in Lackawanna County, Penna.  where there are 90,000 households.  The average household uses about 900 kWh/month or 10 MWh per year. But residential use is only 1/3 of total use, the other 2/3's going to manufacturing and business.  In actuality the share of each household is 30MWh per year. A 2 MWh turbine operating at 33% capacity (doubtful, more like 27%) over 8760 hours per year creates about 6,000 MWh per year.  The 90,000 housholds each use 30 MWh per year or 2,700,000 MWh per year.  That is the electrical power needed to supply my county in an entire year.  So our county would need 2,700,000/6,000 = 450 2 MW turbines operating at 33% capacity "theoretically" to supply my county. Now in the entire state of Penna we only have 460MW installed or half of the 900 MW's that my county would need. http://www.awea.org/PROJECTS/projects.aspx?s=PennsylvaniaWeather/wind does vary, but my eyeball estimate is that you would need 1,000 miles or so between projects to make any difference.  When the wind is not blowing here in Penna it is not blowing in NY or MD or even VT.  The same goes for Texas, I would think that the wind patters across the state are homogenous. You write the "obstacles are political" to providing ALL OF THE US ELECTRICITY FROM WIND?? Do you have any idea how many tens of thousands or maybe hundreds of thousands of windturbines we would need?  We have 200,000 people in Lackawanna County, USA popluation is 300 Million, Multiply 450 times 1500, USA would need 675,000 wind turbines and an ENORMOUS superbly complicated grid and even that would not work with high pressure over the Eastern United States. http://nofreewind.blogspot.com/2009/04/how-many-wind-turbines-per-household.html

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14. 

    Gar Lipow Posted 2:51 pm
    19 Aug 2009

    OK, you give the the number of wind turbines needed to supply all electricity as 675,000. If anything that is probably low. But close enough - so say 70,000 wind generators built and installed annually over th course of ten year. In contrast we produce between 7,000,000 and 11,000,000 automobiles in the U.S. each year What about your "supercomplicated" grid? Include HVDC connectiors along with general quality upgrades and we ship power thousands of miles.   Realistically of course we would mix in solar because it tends to be complementary to wind power, geothermal and hydro power to produce a small amount of non-variable renewable energy for shaping, storage in the form of flow batteries to help match wind supply to demand. (If the solar was CSP, we could use thermal storage which is much cheaper for the solar portion.) Finally for backup we could natural gas, which with all these other things in place would represent between 1% and 4% of total generated kWh, though a much higher percent of capacity.  To refine further - add efficiency to reduce demand. Also on the supply end there is recycled energy which might supply 5% to 20% of electricity from waste industrial heat.

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