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Thread: Berkeley bans natural gas in new homes

  1. #61
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    That would be quite easy. Hydroelectric plants are very easy to throttle. The turbines turn all the time, whether they are generating power or not. In fact, they are operated in idle mode sometimes to correct the grid power factor. All you have to do to throttle up a hydro generator is open the spigot. That takes seconds.

    Quote Originally Posted by Mike Cutler View Post
    I would be very impressed to see a dead stop hydro turbine,of any significant size, go from cold steel to hitting the grid in 2 minutes. That would be impressive. They're fast, but not that fast. A combined cycle gas turbine can go from cold steel to the grid really fast. That's how they make their money. They have to hit the grid quick to take advantage of energy price spikes. They are sometimes put online and taken off in just a few minutes. When the sale priice per megawatt goes from $30.00 to $1800.00, you have to be ready. Yes, the electric market can be that volatile.

  2. #62
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    Art
    Yes, I understand that.
    I was referring to a dead stopped turbine, not one that was continuously spinning and only had to have the generator engaged and sync's to the grid.
    I helped overhaul all the control and electrical systems for a small hydro turbine, I think it was < 300kw, most of the controls were old style relay logic with the big noisy GE HGA style relays. The sync control was more or less manual, no Seimens, or Allen Bradley PLC's.
    Once the turbine was up and running and the speed controller took over, engaging the generator and syncing was quick. It's the speed/load control circuits that need a little time to smooth out. It was a horizontal shaft ,so there were hydraulic systems that had to be brought up to temp and pressure to control vibration.
    We're running one of the newest generation GE Turbine controls systems at work and it's a huge step up from the 1960's vintage GE system it replaced. It's really nice.
    "The first thing you need to know, will likely be the last thing you learn." (Unknown)

  3. #63
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    Quote Originally Posted by Doug Garson View Post
    I'm always amazed when I hear that islands like the US Virgin Islands don't already generate the majority of their electricity from wind and solar. I believe they are in the process of getting their by 2025.
    https://www.energy.gov/eere/technolo...virgin-islands

    I am equally amazed. We had a massive solar field that the same year it was completed it was totally destroyed by Irmaria (Irma and Maria). They should have used three support struts instead of two, but hind sight is 20/20. We had a test wind turbine going up at the landfill, but it was damaged on installation and that was that. The mall put up two massive wind turbines, but WAPA sued them and said that they could not sell power to their tenants because that would be an illegal municipality. Corruption won. The turbines sat unused.

    My quote for 15 panels and one Tesla Powerwall plus installation came to just over $25k. Iím likely doing it. The tax break makes it worthwhile. It would make me mostly off-grid, but just at my normal usage. On laundry day and cloudy days I would likely still be using WAPA, but Iím okay with that. After Irmaria I was without power for 3 months. After Dorian for only a day and a half, but it would have been nice to have solar. Iím aware there is a risk to storm damage, but Iíll take that risk.

  4. #64
    Quote Originally Posted by Malcolm McLeod View Post
    And yet there is some painful shred of truth in all of mine. But let's summarize others:

    Solar-powered uphill pumping of water at night, so we can hydro-generate the next day at peak demand (a SWAG at total process efficiency approaching 2-3%).
    Zero-emission EVs also charged at night from solar or wind, or maybe from out-of-state coal plants.
    Wind turbines that are out of sight for when the wind sometimes blows (so long as no birds are maimed).
    Hydro w/ no dams, no rivers obstructed, and no land flooded.
    Solar panels that are apparently transparent (again, the view) or hidden on someone else's roof.
    Nuclear ... well that just clearly ain't gonna happen.

    Seems like enough ridiculousness to be more than one person. IMHO. But it can be me if you wish.
    If there is any truth in your comments it's well hidden. Let me take one of your comments - that pumped water energy storage has a 2 -3% efficiency.

    1. Do you really think that all of those pumped water energy storage systems would have been built if the efficiency was only 2-3%? If there was just one you might think they made a mistake but there are many systems.

    2. You can do a back of the envelope calculation of the efficiency of conversion of electrical energy to potential energy. Even taking conservative estimates for losses I'm sure you'd come up with better than 2-3%. In a perfect system all of the electrical energy would be converted to potential energy, and then back to electrical energy. Then start subtracting the losses: The motor efficiency, the pump losses, the friction in the pipe, evaporation of some of the water in the reservoir, losses in the generation of electricity from the water.

    3. This is the easiest: Google "efficiency of pumped water energy storage" and see what comes up. Here's one article that says the efficiency is between 70 and 80%.

    If you want your comments to be taken seriously, check the accuracy of your beliefs and state what evidence you have that supports your beliefs.

    Mike

    [It's bad to lie to others, but it's worse to lie to ourselves.]
    Last edited by Mike Henderson; 08-31-2019 at 12:48 PM.
    Go into the world and do well. But more importantly, go into the world and do good.

  5. #65
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    Quote Originally Posted by Mike Henderson View Post
    ... Here's one article that says ... [It's bad to lie to others, but it's worse to lie to ourselves.]
    Since we're accepting the citation as Gospel, please read the first paragraph in this citation very carefully. And have a wonderful holiday!
    Molann an obair an saor.

  6. #66
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    Or maybe it will just mildly offend a protected class, but it will be inadequate somehow.
    Could one of those "mildly offended protected classes" be the fossil fuel industry?

    Quote Originally Posted by Malcolm McLeod View Post
    Since we're accepting the citation as Gospel, please read the first paragraph in this citation very carefully. And have a wonderful holiday!
    Could this be to what is being referred?:

    Low-cost surplus off-peak electric power is typically used to run the pumps. During periods of high electrical demand, the stored water is released through turbines to produce electric power. Although the losses of the pumping process makes the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest.

    Pumped-storage hydroelectricity allows energy from intermittent sources (such as solar, wind) and other renewables, or excess electricity from continuous base-load sources (such as coal or nuclear) to be saved for periods of higher demand.
    This is a method of storing energy similar in theory to a battery. If wind turbines are producing power through the night when power isn't being used, it is a cost effective way to store energy for use when the system needs every kilowatt it can get to meet demand.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  7. #67
    Quote Originally Posted by Malcolm McLeod View Post
    Since we're accepting the citation as Gospel, please read the first paragraph in this citation very carefully. And have a wonderful holiday!
    Sorry, you'll have to be more specific that that.

    And if you believe the information is incorrect, please point to a reliable source that provides the information you do believe to be correct.

    If it's just that you don't like Wikipedia, there are other studies available on the web. Here's one. Here's one that includes the math. One more. There seems to be quite a few studies available.

    Mike
    Last edited by Mike Henderson; 08-31-2019 at 2:06 PM.
    Go into the world and do well. But more importantly, go into the world and do good.

  8. #68
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    Quote Originally Posted by Mike Henderson View Post
    Sorry, you'll have to be more specific that that.

    And if you believe the information is incorrect, please point to a reliable source that provides the information you do believe to be correct.

    If it's just that you don't like Wikipedia, there are other studies available on the web. Here's one. Here's one that includes the math. One more. There seems to be quite a few studies available.

    Mike
    Last one I promise.... Wikipedia is fine! All of your references are fine! Use them, live them, enjoy them.

    For the reading public:
    "Low-cost surplus off-peak electric power is typically used to run the pumps. During periods of high electrical demand, the stored water is released through turbines to produce electric power. Although the losses of the pumping process makes the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest."

    I was desperately attempting optimism, but my 2-3% SWAG is way off. Process efficiency is instead in the negative column (and is very different from 'economic efficiency'). Please build as many of these as you can afford.
    Molann an obair an saor.

  9. #69
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    Quote Originally Posted by Malcolm McLeod View Post
    Last one I promise.... Wikipedia is fine! All of your references are fine! Use them, live them, enjoy them.

    For the reading public:
    "Low-cost surplus off-peak electric power is typically used to run the pumps. During periods of high electrical demand, the stored water is released through turbines to produce electric power. Although the losses of the pumping process makes the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest."

    I was desperately attempting optimism, but my 2-3% SWAG is way off. Process efficiency is instead in the negative column (and is very different from 'economic efficiency'). Please build as many of these as you can afford.
    You seem unwilling, or unable, to understand the concept of, and the reason for energy storage, so your participation in this discussion is only serving to annoy and provoke others.

  10. #70
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    Quote Originally Posted by Malcolm McLeod View Post
    Last one I promise.... Wikipedia is fine! All of your references are fine! Use them, live them, enjoy them.

    For the reading public:
    "Low-cost surplus off-peak electric power is typically used to run the pumps. During periods of high electrical demand, the stored water is released through turbines to produce electric power. Although the losses of the pumping process makes the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest."

    I was desperately attempting optimism, but my 2-3% SWAG is way off. Process efficiency is instead in the negative column (and is very different from 'economic efficiency'). Please build as many of these as you can afford.
    Any storage method will be a net consumer of energy overall. That is- no method of storage will be 100% efficient, therefore there are losses which are consumption of energy.

    Lets take the 70% efficient statement later in the article

    If I put into the system 100 joules of energy into the system, the potential energy of the water moving from the lower to upper reservoir is increased but not by 100 joules since there are some inefficiencies in the pumping, when that water is released through the turbine and is used to generate power the amount of power generated is 70 joules. So we have consumed 30 joules to pump the water up and then to flow back down to reconvert to electricity. That is consumption of power. It is not consuming more power than is put in, which I think is what you are implying by "negative" efficiency.

    All power storage systems will have this problem. Power storage entails using energy to change the potential energy of a system(chemical, mechanical, physical..) and then converting the potential energy to kinetic energy when you need.
    It will never be 100% efficient. (thank you 2nd Law of Thermodynamics)


    (I'm kind of sorry I pointed out the pumped hydroelectric storage)

  11. #71
    Folks, it looks like this topic has been pretty much beat to death and is starting to get a little border line on factual information and some of you are starting to get a little personal in your comments and responses. Everyone please take a deep breath and think for a minute before posting additional information.
    Lee Schierer
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    Captain USN(Ret)

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  12. #72
    Quote Originally Posted by Malcolm McLeod View Post
    Last one I promise.... Wikipedia is fine! All of your references are fine! Use them, live them, enjoy them.

    For the reading public:
    "Low-cost surplus off-peak electric power is typically used to run the pumps. During periods of high electrical demand, the stored water is released through turbines to produce electric power. Although the losses of the pumping process makes the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest."

    I was desperately attempting optimism, but my 2-3% SWAG is way off. Process efficiency is instead in the negative column (and is very different from 'economic efficiency'). Please build as many of these as you can afford.
    Batteries are net consumers of energy. You get out less than you put in. But batteries provide value.

    I don't think you understand the concepts of energy storage.

    Mike

    [Suppose that at night you can buy energy for $1 per unit so you buy 100 units for $100. But during the hottest part of the day, you can sell the 70 units that you get from your storage system for $10 per unit, or $700. It costs quite a bit to build the energy storage system and that profit is the reward for taking the risk and investing in energy storage.]
    Last edited by Mike Henderson; 08-31-2019 at 8:32 PM.
    Go into the world and do well. But more importantly, go into the world and do good.

  13. #73
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    Quote Originally Posted by Mike Henderson View Post
    Batteries are net consumers of energy. You get out less than you put in. But batteries provide value.

    I don't think you understand the concepts of energy storage.

    Mike
    There is also a need to understand when wind generators are spinning at night with no one using their output they may as well be used inefficiently to pump water up to a holding facility to allow it to produce more energy when the system is straining to provide for the demand.

    The equation to consider is the practicality of using energy at a cost of 10Ę a kilowatt hour to store energy with the ability to be sold during a high use period for two, three or more times as much per kilowatt hour.

    It may be an inefficient use of energy but it is profitable for the electric supply system.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  14. #74
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    Quote Originally Posted by Lee Schierer View Post
    Folks, it looks like this topic has been pretty much beat to death and is starting to get a little border line on factual information and some of you are starting to get a little personal in your comments and responses. Everyone please take a deep breath and think for a minute before posting additional information.
    YEP! Let's move on to something less contentious ---um climate change?

    Bruce
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  15. #75
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    Within the last year I read about a German? proposal for a energy storage system that can be built anywhere. it is just an electric tower crane that picks up heavy concrete blocks and stacks them up into massive towers around the crane. When energy is needed it picks them up, one at a time, and lowers them to the ground. This lowering uses dynamic brakes to make power on the way down. Of course not much useful energy until you get to the blocks up really high with a long way to fall. Not very safe in a earthquake or high wind.
    Bill D.

    On edit: They claim 85% efficiency!

    https://qz.com/1355672/stacking-conc...-store-energy/
    Last edited by Bill Dufour; 09-02-2019 at 7:40 PM.

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