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  • #91
    Originally posted by J.P.M. View Post

    Beyond my admittedly simple allegory, but analogous to hydroelectric power needing storage because the source of the hydro power produced is not steady or even predictable (rain), other types of power generation and in the end the grid itself can benefit from storage. The trick is to make the storage safe, practical, cost effective and probably scalable.
    If the bread is going out the door faster than you can bake it why would you set any aside? A kWh is a kWh.

    The reservoir of a hydro plant is more of a fault than a feature. If it was viable to immediately convert incoming water into a kWh that would be the most cost effective approach. The powerhouse is a bottleneck.

    You're missing the biggest problem with storage, why I keep repeating the fact we need SURPLUS renewables for mass storage to be viable and why the fact we lack mass storage is an indication of need not ability. There's an energy cost to storage. It makes no sense to store a GWh and use 900MWh later if you can just use that GWh now. If we added mass storage now without sufficient renewable generation emissions would go UP at least ~10%. You'd be spending $$$ to make negative progress. For the 3rd time now.... why, why would you invest in storage to move chairs around the titanic when you can spend money to pump water OUT with more renewables?

    Originally posted by DanS26 View Post
    Coal and nuclear power are dead.....not just dead but dead, dead, dead. (at current level of technology)
    Agreed; We need non-thermal nuclear. Not even sure how that would even work...

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    • #92
      Originally posted by nwdiver View Post

      .....

      The reservoir of a hydro plant is more of a fault than a feature. If it was viable to immediately convert incoming water into a kWh that would be the most cost effective approach. The powerhouse is a bottleneck.......
      FYI, there are a few small hydro facilites in the Sierras in California that do not have large resevoirs. They rely on long penstock pipes to get the pressure for efficient hydro power generation. Those facilities do not lend themselves well to the storage of energy in resevoirs.

      Also in California I do see some examples of storage being built in conjunction with solar farms. I dont know what the driver is for those investment decisions to include storage. It may be unique to the California market. I can only speculate that since many of those investments are made with Power Purchase Agreements the return on investment may be greater if the solar farm has more flexibility on when it can deliver power. I can think of a couple scenerios where that might be true.
      Last edited by Ampster; 09-14-2020, 10:00 PM.

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      • #93
        Originally posted by DanS26 View Post
        I sat on the board of directors of a medium size electrical utility. ............

        Low cost production wins. Coal and nuclear power are dead.....not just dead but dead, dead, dead. (at current level of technology)

        But production was not our highest cost....it was transmission. And there is where we need more research. IMHO for every dollar we spend on electrical production and storage research we should spend $2 on electrical transmission research. Ultra low loss or no loss electrical transmission is the holy grail. It practically eliminates all the production and storage problems we are grappling with today. It sure would be a game changer. I hope to see it yet in my lifetime.
        I studied economics under disciples of Milton Friedman and still believe in market economics. Transmission is one of those things that scales up significantly and is more efficient if there is one provider in a particular market. I think there are national issues with transmission of electricity, especially in the the rest of the country east of California. I am not up to speed on the efforts to have some kind of west coast ISO but the current capacity crisis indicates some need for that.

        What I have heard is that the ability to place battery storage on substation real estate has solved some of the distribution issues but that is only anecdotal and I don't know how that scales up and mitigates some of the transmission issues. Even though I am pursuing a strategy of being self sufficient I still rely on the grid to charge my EVs and would be willing to pay a fixed fee for my connection if I could be assured those funds would go into improving the flexibility of the transmission and distribution network.

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        • #94
          Originally posted by Ampster View Post

          What I have heard is that the ability to place battery storage on substation real estate has solved some of the distribution issues but that is only anecdotal and I don't know how that scales up and mitigates some of the transmission issues.
          I've read that too. IIRC the primary use of storage on the grid is easing transmission constraints. If you need an extra 10MW at a bottleneck for an hour or so it can be cheaper to add a 20MWh battery than re-conductor 40 miles of wire.

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          • #95
            Originally posted by nwdiver View Post

            I've read that too. IIRC the primary use of storage on the grid is easing transmission constraints. If you need an extra 10MW at a bottleneck for an hour or so it can be cheaper to add a 20MWh battery than re-conductor 40 miles of wire.
            This is only anectdotal information from a consultant but an example was used that said the same thing for disrtribution, I was working with the staff of a city I used to live in on a CEC proposal for a grant for a micro grid for a new fire station and emergency services.buiding. The consultant helping us put the proposal together gave an example of a school district in the Central Valley of California that installed a micro grid and the impact was that it changed the load in that area such that PG&E was able to defer several hundred thousand dollars of infrastructure upgrades previously sheduled for that area.

            Technology is creating some solutions that were not possible in the past. It is creating problems too, because the information and control systems are not bidirectional even though a transformer is natively bidirectional.

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            • #96
              Originally posted by Ampster View Post

              FYI, there are a few small hydro facilites in the Sierras in California that do not have large resevoirs. They rely on long penstock pipes to get the pressure for efficient hydro power generation. Those facilities do not lend themselves well to the storage of energy in resevoirs.

              Also in California I do see some examples of storage being built in conjunction with solar farms. I dont know what the driver is for those investment decisions to include storage. It may be unique to the California market. I can only speculate that since many of those investments are made with Power Purchase Agreements the return on investment may be greater if the solar farm has more flexibility on when it can deliver power. I can think of a couple scenerios where that might be true.
              By definition, available head (height) less velocity head loss at the turbine outlet determines available water pressure at the turbine inlet. That and available flowrate determine available power. The elevation head was there before the reservoir, otherwise the reservoir height would not be possible. As a practical matter the reservoir height will not exceed the site head available before the dam was built. Water storage behind dams helps make the available energy easier to regulate. Site conditions, geology and other factors determine what type of storage is possible or necessary.

              As for efficiency, that's largely a matter of turbine efficiency (low friction losses) and turbine outlet mass velocity considerations and requirements. If all the flow energy from the turbine were extracted the exit velocity of the water would need to be zero. So, some velocity head or flow energy is needed to move the water away from the turbine outlet. Small turbines, say < maybe a couple of MWe that are well maintained can have conversion efficiencies well above 80 %. Larger turbines such as used at the Niagara power projects have efficiencies well above 90 %. Beyond some small head and/or small flowrate, or for very low head applications, head, or as you seem to be calling it "long penstock pipes" has little to do with efficiency. Very low mass velocities (but not necessarily flow fluid velocities) however do impair turbine efficiencies, mostly due to scaling (size) considerations that make some types of more efficient turbines un suitable for small applications.

              I'd encourage folks to check out Sierra Nevada hydro projects of the type Ampster is writing about. They are generally characterized by systems of dams at varying elevations with the higher dams penstocks feeding a turbine that empties into a reservoir created by a dam. Some of the flows are not as great as some other projects of greater mass flowrates, but the total system output can be quite high due to very large total elevation changes of up to ~ 7,000 ft.
              The Big Creek Project, for example has 9 lakes created by dams that cover about 12 sq. miles total.

              Take what you want of the above. Scrap the rest.

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              • #97
                Originally posted by J.P.M. View Post
                ,,,,
                I'd encourage folks to check out Sierra Nevada hydro projects of the type Ampster is writing about. ..........
                The Big Creek Project, for example has 9 lakes created by dams that cover about 12 sq. miles total.
                ,,,.
                Yes it was one or two two of the Big Creek projects I was referring to. Some of those were originally built by Henry Huntington to power his Pacific Electric trolley car system in Los Angeles.That is how Huntington Lake got its name.

                SCE acquired the generating assets and the transmission lines and some time in the sixties built one more facility. By then building dams was so full of hurdles that SCE built a power plant inside the mountain a thousand feet or more below the wide spot in the river where the penstocks catch the water. For whatever reason those assets were not divested with all the other generating assets during deregulation.

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                • #98
                  Originally posted by J.P.M. View Post

                  ................
                  The Big Creek Project, for example has 9 lakes created by dams that cover about 12 sq. miles total..
                  A lot of the Big Creek is now gone in the fire. I hope they will be able to rebuild and not be tied up in greenwashing BS

                  https://en.wikipedia.org/wiki/Big_Cr...ectric_Project

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                  • #99
                    Originally posted by Mike90250 View Post

                    A lot of the Big Creek is now gone in the fire. I hope they will be able to rebuild and not be tied up in greenwashing BS

                    https://en.wikipedia.org/wiki/Big_Cr...ectric_Project
                    Most of the power plants were concrete but the employee housing and SCE's conference center were all stick construction, I hope they can rebuild. My sympathies to those affected

                    Shaver Lake is part of that complex and a smaller version was originally built to store water for a lumber mill and the water was used to flume the cut boards down to the valley where the water was sold to the farmers.
                    Thanks for the link, It has been 25 years since I went on an SCE tour of that facility and my recall of the details was fuzzy, My daughter spent a week or two at one of the camps in the area and I have fond memories of going on a camping trip there in the fifties.
                    Last edited by Ampster; 09-15-2020, 02:58 PM.

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