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  • Interesting Article on Energy Storage

    Howdy All,

    I just read this and thought it was interesting enough to share

    http://indaily.com.au/opinion/2016/1...-store-energy/

    Cheers.

  • #2
    Yeah, pumped storage can handle really large amounts of energy.

    Gotta have two bodies of water at different heights, though.
    https://en.wikipedia.org/wiki/Pumped...droelectricity says
    "The main disadvantage of PHS is the specialist nature of the site required, needing both geographical height and water availability. Suitable sites are therefore likely to be in hilly or mountainous regions, and potentially in areas of outstanding natural beauty, and therefore there are also social and ecological issues to overcome."
    But a pair of big abandoned mine pits does nicely:
    http://energyandmines.com/2016/09/au...nergy-storage/

    Lazard's second annual "levelized cost of storage" report, lazard.com/media/438042/lazard-levelized-cost-of-storage-v20.pdf,
    provides some cost numbers supporting the idea that pumped storage is cheaper than most alternatives (assuming you have two bodies of water handy).

    (It also lists zinc batteries and compressed air storage as competitive on cost, but cautions that zinc batteries are as yet unproven, and that compressed air storage depends on having a giant cavern or the like handy.)

    San Diego's considering adding a 500MW pumped storage facility: http://www.windpowerengineering.com/...orage-project/

    And it looks like Virginia's trying to add a little pumped storage in coal country? utilitydive.com/news/virginia-lawmakers-pass-bill-for-new-utility-pumped-hydro-storage-facilitie/436095/
    Last edited by DanKegel; 02-14-2017, 11:03 AM.

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    • #3
      Here's a rather bullish report on pumped storage in Australia: anu.edu.au/news/all-news/hydro-storage-can-secure-100-renewable-electricity

      They advocate small but high-elevation-difference systems to reduce cost. Excerpt:

      The area of land required for large scale off-river PHES is small. For example, 20 GW of PHES capacity with 20 hours of storage (400 GWh), a head of 600 m and depth of 20 m requires a total reservoir area (upper and lower) of 36 km2 . This represents 5 parts per million of the Australian land mass, and is far smaller than the existing area of artificial reservoirs.
      ...
      The unit off-river PHES system is assumed to have a power of 200 MW, a head of 600 m, twin 20 m deep 5 hectare "turkey nest" ponds with earth walls built on flat land, penstock slope of 13 degrees, easy access, minimal flood control measures and a round trip efficiency of 80%. The estimated cost is $800 per kW (for penstocks, machinery and power conversion) and $70 per kWh (for pond excavation and construction)
      ...
      LCOB is minimized by utilizing PHES to store excess energy for later use (and thus minimize spillage), and by distributing PV and wind very widely using HVDC/HVAC (to take advantage of different weather systems in different regions). In some regions the output of PV and wind are counter-correlated and so utilization of both can reduce LCOB.
      Their modelling predicts that 300-500 GWh of storage will be required for all of Australia (hence the 400 GWh in the above quote).

      It remains to be seen if there really are that many flat sites with 600 meters of head available.

      To those that feel that such studies are mere pie-in-the-sky: perhaps. But it's there to stimulate discussion and further study. You can't answer the question if you don't ask it.
      Last edited by DanKegel; 02-28-2017, 10:54 AM.

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      • #4
        Originally posted by DanKegel View Post
        Here's a rather bullish report on pumped storage in Australia
        Their modelling predicts that 300-500 GWh of storage will be required for all of Australia (hence the 400 GWh in the above quote).

        It remains to be seen if there really are that many flat sites with 600 meters of head available.
        600 meters of head??!! Hoover dam is only 221 meters. Bruce Roe

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        • #5
          Originally posted by bcroe View Post

          600 meters of head??!! Hoover dam is only 221 meters. Bruce Roe
          So I am confused. Are they saying you do not need a major difference in elevation for pumped storage to generate a lot of power but can just use a much larger area with a smaller elevation difference to store the water to generate the power?

          Don't you have to consider evaporation losses and the ability to replace that water in the power calculations? Isn't that one of the problems CA ran into with the recent drought and the reduction of hydro power generation last year.

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          • #6
            Dan:

            With respect to pumped storage, I don't believe any of this is new information. It's all very nice, but it's a well developed technology that's been around for a lot time, known for longer, and has application for large use in often geographically limited ways.

            It comes down to turning current kinetic energy into potential energy, and then storing that potential energy for later transformation back to kinetic energy using gravity for water storage and the semi recoverable energy of compression for storing energy in gasses. I suppose you could also use bowling balls and conveyor belts and get some use of it.

            Pumped hydro is quite efficient. Energy storage in compressible or liquefied gasses much less so. Large pumped storage can have large environmental and/or aesthetic considerations as well, and something the treehuggers seem to often and conveniently not notice.

            What's the point of talking about something that's been around and in use for going on 100 years and a pretty well developed technology ? Turbine design for hydro has been around longer with not much improvement in efficiency for sites with reasonable size, head and economics. Same for gas compression.

            You bust my onions about being anti progress on occasion. Most of the technology and engineering issues with hydro and pumped storage have been around and dealt with since the 19th century.

            Can't you find something more current to regale us with except more sophomoric me-too-ism ?

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            • #7
              The coolest power plant I ever worked in was TVA's Racoon Mountain pumped storage facility. They pump water out of the river at night to fill a 500 acre reservoir 1000' above (on top of the mountain). Then in the daytime, the reverse the pump motors as generators and let the water back into the river. The turbines are in a man made cavern about a 100 feet below the river elevation. I rebuilt 3 of their start breakers a few years ago.

              The plant is used as a regulator for the nuke down the road.

              Greg

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              • #8
                Originally posted by GRickard View Post
                The coolest power plant I ever worked in was TVA's Racoon Mountain pumped storage facility. They pump water out of the river at night to fill a 500 acre reservoir 1000' above (on top of the mountain). Then in the daytime, the reverse the pump motors as generators and let the water back into the river. The turbines are in a man made cavern about a 100 feet below the river elevation. I rebuilt 3 of their start breakers a few years ago.

                The plant is used as a regulator for the nuke down the road.

                Greg
                Pump hydro is a great way to store energy. But the problem has always been the logistics of having an elevated area to pump up to and store the water so that you can then later let gravity pull down the water to run the turbines and generate power. Unfortunately there is just not enough mountains around to make that work every where but it does work real well in some places.

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                • #9
                  Originally posted by SunEagle View Post

                  Pump hydro is a great way to store energy. But the problem has always been the logistics of having an elevated area to pump up to and store the water so that you can then later let gravity pull down the water to run the turbines and generate power. Unfortunately there is just not enough mountains around to make that work every where but it does work real well in some places.
                  Check out the Niagara Power Project, or the one across the river in Canada, the Sir Adam Beck generating station. You need a lot of height or a lot of water, or preferably as much of both as you can wring out of mother nature.

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                  • #10
                    Originally posted by SunEagle View Post
                    Pump hydro is a great way to store energy. But the problem has always been the logistics of having an elevated area to pump up to and store the water so that you can then later let gravity pull down the water to run the turbines and generate power. Unfortunately there is just not enough mountains around to make that work every where but it does work real well in some places.
                    Yep. And I would point out that, by far, the best "storage" you can get is conventional hydro power you don't use. Thus intermittent renewables + hydro are pretty compelling, where that makes sense.

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                    • #11
                      Originally posted by J.P.M. View Post

                      Check out the Niagara Power Project, or the one across the river in Canada, the Sir Adam Beck generating station. You need a lot of height or a lot of water, or preferably as much of both as you can wring out of mother nature.
                      I agree. Surprisingly there is still a number of places in North America where you can place a water turbine on a river or flowing water source without creating a blockage or damn to generate some amount of power as well as places to pump water up to some type of holding tank or reservoir where it can later fall back down again and run a turbine.

                      But even if you add up all of the power generated from all of those turbines, it is still small peanuts to what we consume on a daily basis. Hydro is a great way to generate power but sadly IMO the people of the US probably waste more electricity on a daily basis then we can generate from hydro.

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                      • #12
                        Originally posted by SunEagle View Post
                        So I am confused. Are they saying you do not need a major difference in elevation for pumped storage to generate a lot of power but can just use a much larger area with a smaller elevation difference to store the water to generate the power?
                        I bet Bruce is just saying 600 meters (2000 feet) is really, really tall.

                        ucdenver.edu/faculty-staff/dmays/3414/Documents/Antal-MS-2014.pdf has a list of operational pumped storage plants in the US.
                        The one with the tallest hydraulic head is Helms, which it lists as having a head of 1645 feet, or 500 meters.
                        So it's not out of the question.
                        Last edited by DanKegel; 02-28-2017, 01:05 PM.

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                        • #13
                          Originally posted by SunEagle View Post
                          even if you add up all of the power generated from all of those turbines, it is still small peanuts to what we consume on a daily basis.
                          The amount of pumped storage needed might not be as big as you think.
                          The report I linked to says Australia uses 35 GW peak power & 560 GWh per day average, and yet says its needs could be met reliably with a combination of measures including as little as 14 GW & 400 GWh of pumped storage.

                          Trying to figure out which part you object to.
                          Do you agree that 14 GW of pumped storage might potentially suffice for Australia (given enough transmission capacity, the optimal mix of wind and solar, and demand management),
                          and only argue that getting 14 GW of pumped storage is impractical? Or do you think the report is wrong about how much storage is needed?

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                          • #14
                            Originally posted by DanKegel View Post

                            The amount of pumped storage needed might not be as big as you think.
                            The report I linked to says Australia uses 35 GW peak power & 560 GWh per day average, and yet says its needs could be met reliably with a combination of measures including as little as 14 GW & 400 GWh of pumped storage.

                            Trying to figure out which part you object to.
                            Do you agree that 14 GW of pumped storage might potentially suffice for Australia (given enough transmission capacity, the optimal mix of wind and solar, and demand management),
                            and only argue that getting 14 GW of pumped storage is impractical? Or do you think the report is wrong about how much storage is needed?
                            I am not objecting to anything. I am just trying to figure out if the pumped storage area required would be a giant lake out on the open plains or at some raised mountain area that I am unaware of on the Australian continent.

                            If it was on the open plain then wouldn't it be subjected to a lot of evaporation and if so how is that mitigated. I am just trying to get my head around the physics of a hydro pumping station of that size in that location.

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                            • #15
                              Originally posted by SunEagle View Post
                              I am just trying to figure out if the pumped storage area required would be a giant lake out on the open plains or at some raised mountain area that I am unaware of on the Australian continent.
                              I think they're saying you could meet the need with at least 14 GW / 200 MW = 70 smaller stations (and at most about twice that), each with a pair of 20 meter deep, 12 acre pools, separated vertically by 600 meters.
                              They provide maps of potential sites in Queensland and South Australia, color coded by vertical separation.
                              Last edited by DanKegel; 02-28-2017, 04:36 PM.

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