Notices
Results 1 to 36 of 36
Like Tree9Likes
  • 1 Post By adelady
  • 1 Post By icewendigo
  • 1 Post By Harold14370
  • 1 Post By Lynx_Fox
  • 1 Post By Paleoichneum
  • 1 Post By icewendigo
  • 1 Post By jrmonroe
  • 1 Post By danhanegan
  • 1 Post By billvon

Thread: hydro dams a poor economic choice?

  1. #1 hydro dams a poor economic choice? 
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,309
    A study published this weeks finds most large dams built over the past 50 years ran as much as twice their estimated cost with long delays making them uneconomical for most situations.

    "The evidence is conclusive: large dams in a vast majority of cases are not economically viable. Instead of obtaining hoped-for riches, emerging economies risk drowning their fragile economies in debt owing to ill-advised construction of large dams.After a decade-long lull, the construction of large dams has accelerated. Emerging economies of Brazil, China, Ethiopia, Indonesia, and Pakistan among others are rushing to build mega-dams on an unprecedented scale. Yet since 2000, when the World Commission on Dams published its findings, no systematic, global, and independent research has been carried out on the outcomes of large dams.
    The new research by Flyvberg and Ansar has now produced an authoritative investigation of whether large dams work or not, based on the most extensive dataset of its kind.
    The study is based on data from 245 large dams in 65 different countries. The findings show the construction costs of large dams are on average +90% higher than their budgets at the time of approval, in real terms. This result is before accounting for negative impacts on human society and environment, and without including the effects of inflation and debt servicing; including these items, costs and cost overruns are much higher.
    - See more at: http://www.bsg.ox.ac.uk/news/should-we-build-more-large-dams#sthash.7TtyrRwa.dpuf"

    http://www.sciencedirect.com/science/article/pii/S0301421513010926


    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  2.  
     

  3. #2  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,225
    My own view is that hydropower is all well and good, but.

    In most places and most circumstances, there are now - if there weren't so much in the past - much better options for larger power stations. Right now I'm contrasting some ideas.

    Inundating perfectly good farming, grazing, residential and forest lands to build a large enough dam to generate the needed power

    versus

    Putting solar or wind farms on degraded, unusable sites that have been wrecked by contamination or upheaval from mining or military or waste disposal or industrial activity.

    One takes something away in the hope of something else entirely. The other makes sensible, productive use of a resource that's actually a problem in its current state. One's big, centralised, visible, identifiable. The other is tainted from the outset by the acknowledgement of previous failures of foresight and management - and the total power generated equivalent to a large hydro project is not centralised. It's scattered and placed according to the locations of blackfield sites, rather than taking over greenfield sites. Much less appealing psychologically /socially speaking.

    As for the underestimation of costs.

    There are probably a dozen more psychology papers waiting to be written on decision making about projects that just might involve a bit of ribbon cutting and cameras falshing. I think we underestimate the private, unspoken, unacknowledged urges to be involved with, or to control, a big project that's visible - for miles, permanently. We see it in CEOs and politicians making announcements about these things, but long before this moment, there are hundreds or thousands of people who really like the feeling of being part of something big.


    Ascended likes this.
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  4. #3  
    Forum Cosmic Wizard icewendigo's Avatar
    Join Date
    Jun 2006
    Posts
    2,148
    in some regions hydro power is by FAR the cheapest source of electrical power. though whats good in a region is not automatically good in another region.

    i am skeptical i would have to examine it further to see if its bias or misleading for a reason or another. if the study were to have been done in a school founded by a man who became a billionaire thru his connections with the Saudi Royal Family, then i would want to have another independant study just to be on the safe side. btw cost overruns are not unique to hydro power projects.

    i would look at solar panels in the future though, before spending a fortune on a mega projet
    Last edited by icewendigo; April 25th, 2014 at 06:13 PM.
    dan hunter likes this.
    Reply With Quote  
     

  5. #4  
    Time Lord
    Join Date
    Apr 2008
    Posts
    5,305
    At least theoretically hydro must outperform solar and wind, because it exploits the concentrated product of those energies, to wit: Most of the Earth's surface is already blanketed by enormous solar collectors, where thermal energy is converted to excessive moisture; prevailing winds transport laden air to mountain ranges and lift it against gravity, then dump it at high altitude; the transported solar/wind energy - now kinetic - is concentrated by watersheds into tidy, powerful streams of energy; that you can intercept right at the tightest bottlenecks.

    So you can cover Australia with solar panels; but know the South Pacific will always collect more, and deliver more energy to Chile, naturally. It may be better to get that converted to fuel (even at terrible efficiency) then shipped back across the Pacific...?
    A pong by any other name is still a pong. -williampinn
    Reply With Quote  
     

  6. #5  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    The nice thing about hydroelectric is that you can release the water and spin the turbines whenever you need the power. Solar or wind in themselves do not replace hydroelectric. You'd also need some storage system.
    sculptor likes this.
    Reply With Quote  
     

  7. #6  
    Life-Size Nanoputian Flick Montana's Avatar
    Join Date
    Jul 2012
    Location
    Flatland
    Posts
    5,438
    I loathe dams, but I have seen some interesting progress in terms of hydro power installed on the ocean floor and using tides.
    "Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us." -Calvin
    Reply With Quote  
     

  8. #7  
    Forum Cosmic Wizard
    Join Date
    Dec 2013
    Posts
    2,408
    From the articles comes this excerpt:
    Costs aside, mega-dams also take an inordinately long time to build – 8.2 years on average and often more than 10 years. The study shows that these long time horizons leave dam projects particularly ineffective in resolving urgent energy crises and especially vulnerable to currency volatility, hyperinflation, political tensions, swings in water availability and electricity prices, a combination of which constitute the typical dam disaster, which is your typical dam project.
    I think this is true of most projects that involve governments, and most realists expect the costs to be at least double the projected costs.
    There are some other caustic verbiage in the article about overoptimistic boosterism and blatant deception as driving forces for the initial lowball cost estimates.
    I would suggest government job bidding processes are an important factor. I think even if the business people involved in the bidding are aware of the costs they will lowball their bids to win contracts and then charge extra costs during the life of the project.
    Reply With Quote  
     

  9. #8  
    Forum Radioactive Isotope cosmictraveler's Avatar
    Join Date
    May 2005
    Location
    Key West, Florida, Earth
    Posts
    4,789

    Location: Synergy Industrial Park in Temple, Texas
    Site Size: 250 Acres
    Size: 758 Megawatts; Will supply the power needs of approximately 750,000 homes in Central Texas
    Technology: Combined cycle
    Fuel: Clean, natural gas
    Air Permit Received: Oct. 2008
    Construction Start Date: July 2012
    Construction Time: Approximately 24-30 months
    Anticipated Date of Substantial Completion: EY 2014

    Temple Power Plant Facility Highlights
    The Panda Temple I Generating Station will:

    Contribute approximately $1.6 billion to the area’s economy during construction and the plant’s first ten years of operation
    Create 700-800 construction jobs; 27 direct jobs to operate the plant and 45 indirect jobs to support the plant
    Utilize the latest, most advanced emissions-control technology, making it one of the cleanest natural gas-fueled power plants in the United States
    Employ “Quick start” turbines which can achieve 50% power production in 30 minutes and full baseload capacity in 60 minutes
    Support the development of additional renewable generation by closing the generating gap caused when renewable energy suddenly drops offline
    Provide higher power output during high temperature conditions, making the plant ideal for Texas’ hot summers
    Phot


    https://www.google.com/url?sa=t&rct=...U8Kodq1Kq_FnLQ

    This kind of electric generating plant, IMO, would be far better that any hydroelectric type that dams up a river which stops fish from migrating and makes many towns relocate because of the water backup.
    When the power of love overcomes the love of power the world will know peace.
    Jimi Hendrix
    Reply With Quote  
     

  10. #9  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,309
    Another risk of hydro power which can take generations to return on their investment is the changing climate conditions.

    "Faced with dwindling water supplies, the Lower Colorado River Authority, which supplies water and energy to much of Central Texas, is limiting downstream water releases for activities like rice farming. Aside from stirring controversy among water users, the changes have shrunk the amount of electricity the agency generates from its six Colorado River dams."

    http://www.nytimes.com/2014/03/09/us...-era.html?_r=0
    dan hunter likes this.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  11. #10  
    Forum Cosmic Wizard icewendigo's Avatar
    Join Date
    Jun 2006
    Posts
    2,148
    Bam, Pow, Wham, ...yeah, and Dont forget the Hydro piniata starts with H, just like Hitler. And it could be placed so that Manhatan is flooded, if we use this scenario, we can clearly demonstrate that Hydro is bad. Down with Hydro, viva "Clean" "Natural" Gas! Yeehaww!
    Reply With Quote  
     

  12. #11  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,309
    Quote Originally Posted by icewendigo View Post
    Bam, Pow, Wham, ...yeah, and Dont forget the Hydro piniata starts with H, just like Hitler. And it could be placed so that Manhatan is flooded, if we use this scenario, we can clearly demonstrate that Hydro is bad. Down with Hydro, viva "Clean" "Natural" Gas! Yeehaww!
    Stop trolling.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  13. #12  
    Forum Cosmic Wizard
    Join Date
    Dec 2013
    Posts
    2,408
    Quote Originally Posted by cosmictraveler View Post
    ...
    Temple Power Plant Facility Highlights
    The Panda Temple I Generating Station will:

    Contribute approximately $1.6 billion to the area’s economy during construction and the plant’s first ten years of operation
    Create 700-800 construction jobs; 27 direct jobs to operate the plant and 45 indirect jobs to support the plant
    ...
    https://www.google.com/url?sa=t&rct=...U8Kodq1Kq_FnLQ

    This kind of electric generating plant, IMO, would be far better that any hydroelectric type that dams up a river which stops fish from migrating and makes many towns relocate because of the water backup.
    Normally that $1.6 billion should be counted as cost instead of profit.
    Reply With Quote  
     

  14. #13  
    Forum Professor
    Join Date
    Aug 2013
    Location
    San Diego
    Posts
    1,970
    Quote Originally Posted by Lynx_Fox View Post
    A study published this weeks finds most large dams built over the past 50 years ran as much as twice their estimated cost with long delays making them uneconomical for most situations
    This seems to be more an indictment of poorly planned dams rather than dams overall. One could apply the same logic to early solar power plants (like the Arco Carrizo power plant of the 1980's) and declare that ill-advised construction of solar power plants is neither economically nor environmentally viable.
    Reply With Quote  
     

  15. #14  
    Forum Cosmic Wizard
    Join Date
    Dec 2013
    Posts
    2,408
    Good dam sites are a scarce commodity. Almost all the good locations have already been exploited, and the world still needs more electricity.
    One result of this is dams being built in remote locations. Building something in a remote location pushes construction costs and maintenance cost dramatically higher.
    It also means building in hostile environments where weather and disease can cause extra problems.

    Power dams are still the cheapest way to get electricity in most cases but when you look at the costs of building in remote locations and how far you need to build power lines from the dam to the place you want power dams can fall victim to the laws of diminishing returns.
    Reply With Quote  
     

  16. #15  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,309
    The OP study largely echoes the conclusions of another major study published in 2000. It is in large part of poor planning, perhaps influences by the false and loosely based pychological optimism Adelady writes about, but is appears quite common. That 2000 comprehensive study found:

    "
    -Large dams display a high degree of variability in delivering predicted water and electricity services

    -Large dams have demonstrated a marked tendency towards schedule delays and significant cost overruns.

    -Large dams designed to deliver irrigation services have typically fallen short of physical targets, did not recover their cost and have been less profitable in economic terms than expected.

    -Pervasive and systematic failure to assess the range of potential negative impacts and implement adequate mitigation, resettlement and development programmes for the displaced, and the failure to account for the consequences of large dams for downstream livelihoods have led to the impoverishment and suffering of millions, giving rise to growing opposition to dams by affected communities worldwide.

    -Since the environmental and social costs of large dams have been poorly accounted for in economic terms, the true profitability of these schemes remains elusive
    . "

    http://awsassets.panda.org/downloads...nal_report.pdf

    --
    When both studies are considered it seems like dams might not be the cheapest means of producing power in the long run after all.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  17. #16  
    Moderator Moderator
    Join Date
    Nov 2011
    Location
    city of wine and roses
    Posts
    6,225
    Years ago, I used to think that hydro was a pretty good way to go. The more I've learned about fish movements and about the way rivers and their wetlands and deltas distribute and store nutrients, silt and all the rest of it, the less I'm impressed.

    And the money costs seem way out of whack with the power generated - and the fish stocks lost and all the productive land taken out of use or potentially useful lands and forests drowned or sequestered make them less and less attractive to me. I knew that the Aswan Dam was causing all sorts of "unforeseen" problems, like the decrease of fertility in the Mediterranean. Then I was really, really unimpressed with the Chinese building the Three Gorges. Then, surprise, surprise, there are problems with the fisheries further down the river and where it meets the sea, and the loss of silts has increased the risks of sea water incursions around Shanghai.

    There must obviously be a river for such projects in the first place, why not keep the land in use, or if unused keep it available, by installing "run of river" power systems. Or you could extract and pipe part of the water at points where there is a reasonable slope then take power from smaller hydro installations at the point where the water is returned. You keep most, if not all, of the existing natural and economic benefits of having the river in the first place, and you get most, probably not all, of the power you would have generated from the large, centralised installation. A few wind turbines should supplement if any particular region gets less power than anticipated. If you design and implement it right, you'd also be getting additional power generated into the grid as each location comes on line, so the delay in getting a big dam to the point of supplying power is also eliminated.

    Most importantly, you're not stuck with the negative outcomes of a useless, silt filled, oversized concrete bunker one or two hundred years later. And, in the later years leading up to that point, that silt has progressively been making the dam less and less useful for managing floods and water flows for its intended purpose on top of its effects downriver. Presumably, the smaller volumes of water held would also have been reducing the amount of power that could be reliably generated as well.
    "Courage is what it takes to stand up and speak; courage is also what it takes to sit down and listen." Winston Churchill
    "nature is like a game of Jenga; you never know which brick you pull out will cause the whole stack to collapse" Lucy Cooke
    Reply With Quote  
     

  18. #17  
    Time Lord
    Join Date
    Apr 2008
    Posts
    5,305
    Quote Originally Posted by cosmictraveler View Post
    stops fish from migrating
    Depends where you build them. Suppose you build them in the region aptly named Cascadia. AKA the Pacific Northwest. For fish (e.g. salmon) we don't impede fish, but rather help them access new streams with fish ladders. So the watershed above that natural 10m waterfall becomes spawning ground, if you're going there to build anyway.
    A pong by any other name is still a pong. -williampinn
    Reply With Quote  
     

  19. #18  
    Forum Radioactive Isotope Paleoichneum's Avatar
    Join Date
    Oct 2008
    Location
    Washington State, USA
    Posts
    4,564
    Quote Originally Posted by Pong View Post
    Quote Originally Posted by cosmictraveler View Post
    stops fish from migrating
    Depends where you build them. Suppose you build them in the region aptly named Cascadia. AKA the Pacific Northwest. For fish (e.g. salmon) we don't impede fish, but rather help them access new streams with fish ladders. So the watershed above that natural 10m waterfall becomes spawning ground, if you're going there to build anyway.
    Thins is happening only after ~40-60 years of dam building that involved NO fish access at all. The upper reaches of the Columbia River system are a classic example of destroyed fish runs and altered habitat that happened with the construction of Grand Coulee. David Douglas noted the major salmon runs of the interior BC rivers when he journeyed through the region. Those all abruptly died with the dam construction in the 30-60s.
    Flick Montana likes this.
    If more of us valued food and cheer and song above hoarded gold, it would be a merrier world. -Thorin Oakenshield

    The needs of the many outweigh the need of the few - Spock of Vulcan & Sentinel Prime of Cybertron ---proof that "the needs" are in the eye of the beholder.
    Reply With Quote  
     

  20. #19  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,309
    Quote Originally Posted by Pong View Post
    Quote Originally Posted by cosmictraveler View Post
    stops fish from migrating
    Depends where you build them. Suppose you build them in the region aptly named Cascadia. AKA the Pacific Northwest. For fish (e.g. salmon) we don't impede fish, but rather help them access new streams with fish ladders. So the watershed above that natural 10m waterfall becomes spawning ground, if you're going there to build anyway.
    I agree there have been some monumental efforts efforts to help adult salmon pass upstream as well as improve juvenile to survive their trip to the sea increasing turbine redesign, better water release controls (which cuts down on power generation) so water remains well oxygenated, attempts to reroute them into barges etc, but even all those have been far less than entirely successful. For the snake river, for example, wild salmon are far short of historical returns.

    In the project I've followed the most and been politically active in along the Elwha River the only viable means to restore the river and the ecology of the inner Olympic National Park, was to remove the two dams altogether. The dams have been drained and the land it being restored...the next decades will provide a mountain of useful data. A lot of people hope it returns from being one of the least to one of the most productive of salmon.

    Other NW dams have no effective solution--the Wynoochee river salmon return rates are abysmal compared to similar rivers such as the Satsop. The North Fork of the Skokomish salmon returns were nearly zero (I once hopped over in a small jump a once mighty river I should have had trouble fording), and only after decades of legal disputes with Native Americans, now finally releasing water into the river during the summer. If the Pacific Northwest is an example of salmon restoration, it's a darned spotty one.
    -
    Last edited by Lynx_Fox; April 26th, 2014 at 08:15 PM.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  21. #20  
    Time Lord
    Join Date
    Apr 2008
    Posts
    5,305
    Yup, times have changed. If a large dam proposal can't maintain or enhance salmon habitat, it's not happening.
    A pong by any other name is still a pong. -williampinn
    Reply With Quote  
     

  22. #21  
    Forum Cosmic Wizard icewendigo's Avatar
    Join Date
    Jun 2006
    Posts
    2,148
    Stop trolling.
    Ok, fair enough, I just want it to be clear that imo it appears you are cherry picking studies that support a negative bias against a particular energy source. Instead of looking for information about Hydro power, and sharing that, you are deliberately going out of your way to find anything that can support your negative bias, and when you do, you post that cherry picked negative source. Cheers
    Last edited by icewendigo; April 28th, 2014 at 09:51 AM.
    Reply With Quote  
     

  23. #22  
    Life-Size Nanoputian Flick Montana's Avatar
    Join Date
    Jul 2012
    Location
    Flatland
    Posts
    5,438
    While I can't share our unpublished data, I will say that our magnetic susceptibility testing on floodplain soils on the Ohio River yielded in interesting result when we were measuring flood events. We found that, though our magsup still trended with flooding, it had a strong drop-off in potential when damming began on the Ohio. Further research located numerous studies demonstrating reduced sedimentation rates and flood event alteration from damming. This disruption of the natural hydrologic process is reason enough for me to feel apprehensive of future damming efforts. Mitigating these issues costs a lot of money over time and still cannot replicate natural processes.

    Papers:
    Changes in hydrologic regime by dams
    http://onlinelibrary.wiley.com/doi/1...nticated=false


    Anthropogenic sediment retention: major global impact from registered river impoundments


    An Error Occurred Setting Your User Cookie


    River-Sediment Inputs to Major Deltas - Springer
    "Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us." -Calvin
    Reply With Quote  
     

  24. #23  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,309
    I haven't done a comparison....true. That's not the intent of the OP who was simply to show that a major study, (and another one as well), show that a common belief that major hydropower is economical is often not the case. I also didn't present the pros of other types of production as you now say I did. It's also far from cherry picking to show two comprehensive studies across many of the types of projects which show nearly the same result.

    Furthermore your post didn't make such a comparison either backed by anything other than emotional charged rhetoric. It really added nothing to the "balance" you think should be included in the thread. A more somber and reasonable response would have been to show a comparative study showing the life cycle cost of different means of electrical production. Feel free to do so if you wish.
    Last edited by Lynx_Fox; April 28th, 2014 at 10:08 AM.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  25. #24  
    Forum Professor
    Join Date
    Aug 2013
    Location
    San Diego
    Posts
    1,970
    Quote Originally Posted by Pong View Post
    Yup, times have changed. If a large dam proposal can't maintain or enhance salmon habitat, it's not happening.
    Any dam changes a river's habitability, both for better and for worse. Any decision on a dam has to be made based on both parts of that equation.
    Reply With Quote  
     

  26. #25  
    Forum Cosmic Wizard icewendigo's Avatar
    Join Date
    Jun 2006
    Posts
    2,148
    a brief look in wikipedia (I do not have the time to look into this) found that as seen in this OpenEI chart, the Median Levelized Cost of Energy (USD/MWh)of Hydopower 20, is less than Wind offshore(100), Solar(200), Geothermal(60), Biopower(70), Natural Gas(50), Coal(50) and Nuclear(60). While the same is true in France apparently, French energy costs for different generation technologies in Euros per megawatt hour (2011) Technology Cost (€/MWh) are described as;
    Hydro power 20, Nuclear 50, Natural gas turbines without CO2 capture 61, Onshore wind 69, Solar farms 293

    Does that mean anything? Not in a generalized claim sense like "Hydro is a good economic choice", each project needs to be examined on its own. Because it is cheap in region/situation X or Y it doesnt mean its cheap in region Z, and the opposite is true. This is all the more true with Hydro for which variations in regional/topographic/environmental factors play a major part. Plus if a dam in a place where its needed happens to prevent 5 billion dollars of flood disaster reconstructions, its a factor to consider in that specific region.

    So if you need to choose among electric plant options, IMO its incorrect to say "we will disregard a hydro project, because ~Hydro dams are not a good economic choice~", without considering what the specific situation is.
    dan hunter likes this.
    Reply With Quote  
     

  27. #26  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,309
    Good.

    Don't see the link.

    We able to pull up US government estimates of new production that show geothermal and natural gas being the least expensive, with hydro about the same as advanced nuc and on-shore wind, with coal (interesting), being more expensive, solar and offshore wind being the most expensive of all.

    See table 2.
    http://www.eia.gov/forecasts/aeo/pdf...generation.pdf

    So if you need to choose among electric plant options, IMO its incorrect to say "we will disregard a hydro project, because ~Hydro dams are not a good economic choice~", without considering what the specific situation is.

    Fully agree. Though the point of both studies was to cast doubt on the presumption that it was always best and more affordable to build large hydro than other forms of power generation.
    Last edited by Lynx_Fox; April 28th, 2014 at 02:15 PM.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  28. #27  
    Forum Professor jrmonroe's Avatar
    Join Date
    Mar 2010
    Posts
    1,444
    I've felt disinclined to post for a while, but I want to emphasize what everyone has said, large hydroelectric dams. I figured China would opt to build one all-its-eggs-in-one-basket large dam (which I would call a humungous dam), and it did, the Three Gorges Dam. Several smaller dams would have been operationally more robust and would have taken several dispersed nicks out of the local environments and the local human civilizations compared to this monstrosity. For example, it cost China as much to move the dislocated people as it did to build the thing. Then there's the catastrophe of a major electric and/or mechanical failure, along with it being a major target by China's enemies in wartime or otherwise by terrorists.
    Lynx_Fox likes this.
    Grief is the price we pay for love. (CM Parkes) Our postillion has been struck by lightning. (Unknown) War is always the choice of the chosen who will not have to fight. (Bono) The years tell much what the days never knew. (RW Emerson) Reality is not always probable, or likely. (JL Borges)
    Reply With Quote  
     

  29. #28  
    Forum Junior
    Join Date
    Apr 2013
    Posts
    282
    There is also a very significant safety issue with hydroelectric power. This is because dams are known to fail. Not very often, but when they do, the results are catastrophic. The 1975 failure of the Banqaio dam in China is thought to have killed 170,000 people.

    I expect someone will say this could never happen in the United States. I beg to differ, recent economic conditions have led to decreased spending on infrastructure maintenence across the board, and dams are among the most critical. The trouble with dams is they tend to receive lots of publicity when first built, but over time people forget about them and funding for maintenance gradually drops to a trickle. In the long run, dams have only two possible end states, either they fail or they are dismantled. Dismantling a dam is very costly and almost never happens, it is far more common to cut maintenance budgets and pretend the problem doesn't exist.
    adelady likes this.
    Reply With Quote  
     

  30. #29  
    Time Lord
    Join Date
    Apr 2008
    Posts
    5,305
    Quote Originally Posted by Lynx_Fox View Post
    the point of both studies was to cast doubt on the presumption that it was always best and more affordable to build large hydro than other forms of power generation.
    Yeah. Because regions have different topography, weather, resources, etc, they'll wisely choose different power schemes. For much of Northern Canada the best option is to truck barrels of oil to the small communities.

    But here's a question: Suppose the Earth had no human population and no energy infrastructure. Then suppose we want to plop down one energy-hungry smelting town, anywhere on Earth. Where would it be and how would we generate the power?

    The question grows less hypothetical as economies globalize.
    A pong by any other name is still a pong. -williampinn
    Reply With Quote  
     

  31. #30  
    Time Lord
    Join Date
    Mar 2007
    Posts
    8,046
    I notice that they focus on "Large Dam". The size of the dam is virtually irrelevant to the amount of power you get out of it. What matters is the flow rate!!!! of the water. You can build the biggest dam anyone ever imagined on a poor stream that doesn't get very much water flow, and it will still only generate as much electricity as a small dam would have gotten you.

    In contrast, you could build a very small dam at the front of a small stream that has fast flowing water, and you'd get a lot of power out of it.


    Quote Originally Posted by Harold14370 View Post
    The nice thing about hydroelectric is that you can release the water and spin the turbines whenever you need the power. Solar or wind in themselves do not replace hydroelectric. You'd also need some storage system.

    Why do people insist on comparing them, like they're in some kind of competition? Hydro and wind/solar are chocolate and peanut butter. They belong together!!!

    A hydro dam is a storage system, almost better than having a giant lithium ion battery. Turn off the turbines, and water pressure just keeps building behind the dam waiting to be released later. So during the day while it's sunny you turn off the turbines and run the city off of solar power. Then at night you turn the turbines back on and release all that pent up water pressure from the day before.

    I don't know why that beautiful complimentary-ness doesn't get mentioned more in the press.

    Basically having 100 mw of solar + 100 mw of hydro is just about exactly the same as having 200 mw of hydro. You'd rarely notice the difference.
    Some clocks are only right twice a day, but they are still right when they are right.
    Reply With Quote  
     

  32. #31  
    Time Lord
    Join Date
    Mar 2007
    Posts
    8,046
    I should add that hydro suffers from the randomness of the weather just like solar and wind do. It's just over a longer period of time. Some years you get more rain, and some years you get less. So even hydro can benefit from some secondary infrastructure to get you through the drought years.

    (And I'm betting the sun would be out more often during a drought year.)
    Some clocks are only right twice a day, but they are still right when they are right.
    Reply With Quote  
     

  33. #32  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,309
    Quote Originally Posted by kojax View Post
    I notice that they focus on "Large Dam". The size of the dam is virtually irrelevant to the amount of power you get out of it. What matters is the flow rate!!!! of the water. You can build the biggest dam anyone ever imagined on a poor stream that doesn't get very much water flow, and it will still only generate as much electricity as a small dam would have gotten you.

    In contrast, you could build a very small dam at the front of a small stream that has fast flowing water, and you'd get a lot of power out of it. [/quote]


    Drop is as important as flow rate.

    Quote Originally Posted by Harold14370 View Post
    The nice thing about hydroelectric is that you can release the water and spin the turbines whenever you need the power. Solar or wind in themselves do not replace hydroelectric. You'd also need some storage system.

    Why do people insist on comparing them, like they're in some kind of competition? Hydro and wind/solar are chocolate and peanut butter. They belong together!!!

    A hydro dam is a storage system, almost better than having a giant lithium ion battery. Turn off the turbines, and water pressure just keeps building behind the dam waiting to be released later. So during the day while it's sunny you turn off the turbines and run the city off of solar power. Then at night you turn the turbines back on and release all that pent up water pressure from the day before.

    I don't know why that beautiful complimentary-ness doesn't get mentioned more in the press.

    Basically having 100 mw of solar + 100 mw of hydro is just about exactly the same as having 200 mw of hydro. You'd rarely notice the difference.
    [/quote]

    The key part here is grid level solar is thus far the most expensive, the highest carbon producing and polluting option among the renewables and (life cycle considerations), and still requires another form of large scale at nearly 100% of grid requirements base loading or building sufficient continental infrastructure to shunt power where it's needed. I totally agree there's a lot of opportunities to integrate power sources, and we should probably do so, but nearly all of them are expensive options.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  34. #33  
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    When reading about a fusion project recently, the topic of cost over runs was mentioned.
    In the article, it was claimed that gross underestimates of eventual costs were common when seeking government monies. The theory being, that once small sums(read billions) were committed, then the payer was hooked, and could be tapped for continuing funds as the project proceeded.
    It was noted, however that this did not always work, and many projects had been abandoned 1/2 built when the funding ran out.

    Based on the information of the article as/re funding, cost over runs would seem common.

    As Harold said:
    The nice thing about hydroelectric is that you can release the water and spin the turbines whenever you need the power. Solar or wind in themselves do not replace hydroelectric. You'd also need some storage system.
    so added to wind and solar, the storage (of potential energy)capability of hydro assures continuous power to the grid
    Reply With Quote  
     

  35. #34  
    Forum Professor
    Join Date
    Aug 2013
    Location
    San Diego
    Posts
    1,970
    Quote Originally Posted by kojax View Post
    I notice that they focus on "Large Dam". The size of the dam is virtually irrelevant to the amount of power you get out of it. What matters is the flow rate!!!! of the water.
    Power is proportional to flow rate and head. A massive flow in a sedentary river (like the Mississippi or a tidal flow) gives you very little power; the 3000 foot head of a large waterfall would give you massive amounts of power for a very small flow.
    Lynx_Fox likes this.
    Reply With Quote  
     

  36. #35  
    Time Lord
    Join Date
    Mar 2007
    Posts
    8,046
    Quote Originally Posted by Lynx_Fox View Post
    Quote Originally Posted by Harold14370 View Post
    The nice thing about hydroelectric is that you can release the water and spin the turbines whenever you need the power. Solar or wind in themselves do not replace hydroelectric. You'd also need some storage system.

    Why do people insist on comparing them, like they're in some kind of competition? Hydro and wind/solar are chocolate and peanut butter. They belong together!!!

    A hydro dam is a storage system, almost better than having a giant lithium ion battery. Turn off the turbines, and water pressure just keeps building behind the dam waiting to be released later. So during the day while it's sunny you turn off the turbines and run the city off of solar power. Then at night you turn the turbines back on and release all that pent up water pressure from the day before.

    I don't know why that beautiful complimentary-ness doesn't get mentioned more in the press.

    Basically having 100 mw of solar + 100 mw of hydro is just about exactly the same as having 200 mw of hydro. You'd rarely notice the difference.
    The key part here is grid level solar is thus far the most expensive, the highest carbon producing and polluting option among the renewables and (life cycle considerations), and still requires another form of large scale at nearly 100% of grid requirements base loading or building sufficient continental infrastructure to shunt power where it's needed. I totally agree there's a lot of opportunities to integrate power sources, and we should probably do so, but nearly all of them are expensive options.

    The analysis too often bases itself off of present fuel prices. When you're building infrastructure intended to last decades, who cares about present fuel prices? The prices that matter are future fuel prices, and we can be pretty much certain those are going to be going up. And not necessarily because they start to run out. It's going to be because more and more of the world is industrializing - and thereby increasing the demand.

    But.... this is the environment subforum, so I guess we should also consider how much pollution the solar panels will create in the process of being made and being disposed of when they finally stop working. Wind fortunately performs very well in that area. It seems solar only does well if it's some kind of steam or convection based technology, rather than panels.
    Some clocks are only right twice a day, but they are still right when they are right.
    Reply With Quote  
     

  37. #36  
    Time Lord
    Join Date
    Mar 2007
    Posts
    8,046
    Quote Originally Posted by billvon View Post
    Quote Originally Posted by kojax View Post
    I notice that they focus on "Large Dam". The size of the dam is virtually irrelevant to the amount of power you get out of it. What matters is the flow rate!!!! of the water.
    Power is proportional to flow rate and head. A massive flow in a sedentary river (like the Mississippi or a tidal flow) gives you very little power; the 3000 foot head of a large waterfall would give you massive amounts of power for a very small flow.
    Yeah. The energy of a falling object is equal to mass * distance * g. So increasing distance has exactly the same effect as increasing mass. I didn't think to accommodate that. This leads to the conclusion that tall dams are to be preferred over short dams.

    However, wide dams are to be avoided whenever possible.
    Some clocks are only right twice a day, but they are still right when they are right.
    Reply With Quote  
     

Similar Threads

  1. Magneto Thermo Hydro Dynamics
    By Rene Varma in forum Introductions
    Replies: 10
    Last Post: September 17th, 2013, 08:01 AM
  2. Closed Circuit Micro Hydro Electric
    By tucca87 in forum General Discussion
    Replies: 3
    Last Post: February 1st, 2013, 03:46 AM
  3. Elwha River dams closer to removal
    By Lynx_Fox in forum Environmental Issues
    Replies: 3
    Last Post: May 30th, 2011, 12:22 PM
  4. Hydro Electric Power Companies
    By jonathan cole in forum Electrical and Electronics
    Replies: 0
    Last Post: February 2nd, 2011, 03:35 AM
  5. Replies: 0
    Last Post: March 8th, 2009, 04:45 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •