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A power plant that uses more power than it generates

by willib
Tags: generates, plant, power
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willib
#1
Jul16-05, 05:46 PM
P: 228
The Yards Creek Pumped Storage Electric Generating Station is a generating facility that really consumes more power than it generates!
The Yards Creek purpose is to met peak power demands for electricity as people wake up and later in the day as stores open and industry uses more power. Pumped storage while a low investment does have a high operating cost and is used to met only peak demands as the water is pumped up the mountain during non-peak power needs.

The pumped storage plant consists of two areas, one on top of the mountain, primarily the upper reservoir and the lower areas. The water flows by a huge pipeline visible from Allumuchy State Park 40 miles away.




The pumps in the powerhouse are reversible pump turbines that combine with reversible motor-generators that act as motors in one direction when pumping the water uphill and generators when the water flows downhill.
The Yards Creek station has three units each with a capacity of 110,000 kilowatts.






At night when conventional high efficiency power companies have excess capacity and surplus power, the electricity is used to operate the motor-generation as a pump to force water from the lower reservoir to the upper reservoir a mile from the upper reservoir and 700 feet higher in elevation where it is stored until peak electrical usage approaches. The water is used over and over again.

Do to the loses in running the motors and friction in moving the water, it takes 3 kilowatts-hours of pumping uphill to generate 2 kilowatt-hours of electricity when generating. The lower cost of off-peak power to that compared to the rate charged for on-peak power makes the operation cost effective. It is only the cost difference, and low investment of the pump-storage unit vs conventional generator that make "peak power production" from the facitility economical.

The public can visit the yard's education center, picnic areas, natureal lookouts, drinking fountains, comfort stations, parking areas and hiking trails.



Click on map for blow-up of the hiking trails and area map


Power Plant Statistics:
Upper Reservoir 1,560,000,000 Gallons
Elevation 1,555 feet

Tunnel 1,548 feet
Diameter 20 feet
Slope 17 percent

Penstock
Length 1,861 feet
Lower portion 313 feet
Diameter 19 and 18 feet

Power
Rated Electrical Capacity 330,000 kilowatts
Maximum output of turbine 180,000 horsepower each
Kittatinny Substation - 230,000 volt transmission lines

Lower Reservoir 1,760,000,000 Gallons
elevation 818 feet
There were no pictures available , i wonder why..??
try googleing Yards Creek Power Plant
what a waste of power..!!!
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Hurkyl
#2
Jul16-05, 05:51 PM
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Well, the alternatives are:

(1) Have brownouts during the day, because power plants aren't producing enough power to meet demand.

(2) Waste gobs of power at night, because power plants are producing far more than is consumed.
Cyrus
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Jul16-05, 05:52 PM
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Niagra falls does the same thing at night time. As it pumps it up hill, it turns the generators in reverse to make power. During the day, it falls back down, and turns the generators once more to meet peak demands. Electric Generators can only produce so much power druing the day, and if the demands are not high, it only makes sense to use this power that would other wise be wasted to give the water a higher potential energy.

brewnog
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Jul17-05, 06:19 AM
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A power plant that uses more power than it generates

There's a similar system in Llanberis in Wales, - the "Electric Mountain" at Dinorwig. At the time (1985?), it was the largest civil engineering project ever accomplished in the UK, which isn't surprising if you've seen the inside of the generator hall; it's massive, and is actually inside a mountain. You can go on a tour of the facility, it's fantastic.
Clausius2
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Jul17-05, 08:15 AM
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Quote Quote by willib
At night when conventional high efficiency power companies have excess capacity and surplus power, the electricity is used to operate the motor-generation as a pump to force water from the lower reservoir to the upper reservoir a mile from the upper reservoir and 700 feet higher in elevation where it is stored until peak electrical usage approaches. The water is used over and over again.
Well, I am not an expert in this stuff, but I am going to give my opinion. Here there are such power plants also. I think I was taught those power plants have two missions:

i) meeting peak demands.

ii) Pumping Reactive Energy into the electrical system. Usually such turbines are coupled to a synchronous (did I write it right??) motor-generator. These motors are capable of generating Reactive Energy when they works with an appropriate intensity in the rotor. Electrical companies must balance the consumption of Reactive Energy, because this energy is employed by motor consumers to magnetize the machines during the day. Also, insuflating Reactive Energy will stabilize and increase the voltage in some disfavoured electrical node. You know also that an excessive consumption of Reactive Energy is penalized by electrical companies, because it is a more expensive type of energy. So it seems these power plants give more profits to electrical companies than we might think, by the way they wouldn't exist if this last statement is not completely true.

Have I translated rightly the term "Reactive Energy"? I am not sure I did it. I don't know if this power is called so in english.

Anyway, if some electrical engineer is not agree with me, feel free to criticise me (but not too hardly! )
Ivan Seeking
#6
Jul17-05, 08:18 PM
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Clausius2, are you talking about a sliding scale for power rates based on the power factor for each customer?

As for the original post, does anyone know approx. how efficient these systems may be? By a seat of the pants calculation, I land around the 5% range [.9 x .2 x .3 x .9] as a best case, which is about the same efficiency as converting the excess energy into hydrogen, and offsetting peak demands by using the H2 fuel. This has a been one focus for the H2 folks and it looks like they could already be competitive.
hitssquad
#7
Jul18-05, 02:15 AM
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Quote Quote by Clausius2
Have I translated rightly the term "Reactive Energy"?
We call our electrical supply base load, load following, and peak load. Reactive energy sounds to me like load following.
hitssquad
#8
Jul18-05, 02:25 AM
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Quote Quote by Ivan Seeking
how efficient these systems may be? By a seat of the pants calculation, I land around the 5% range [.9 x .2 x .3 x .9]
Where did you get those figures? Willi wrote it takes 3 kilowatts-hours of pumping uphill to generate 2 kilowatt-hours of electricity when generating. That would be a storage efficiency of 67%.



This has a been one focus for the H2 folks and it looks like they could already be competitive.
It is not likely H2 will ever be as efficient as pumped storage. The problem with pumped storage is that there are limitation on places to pump to. We could do like the Soviets did and blast out reservoirs with hydrogen bombs, or we can settle for less-efficient storage technologies such as H2.
Danger
#9
Jul18-05, 03:24 AM
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I'm going to pretty much ignore all of the posts and comment only upon the title of the thread. All electrical generation facilities consume more power than they produce. Even a fusion plant, should an operable one be developed, would be in that category. It's only a partial conversion of one state of energy to another, with attendant losses. When you consider how much energy went into creating deuterium and tritium in the first place, it's obvious that there is really no 'break even' point. It's almost like petrochemicals, where one thinks that oil is a free resource once you get it out of the ground. That doesn't factor in the amount of solar energy and planetary gravity/heat that went into sustaining the lives of the dinosaurs and plants and then squishing them into oil.
Ivan Seeking
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Jul18-05, 03:30 AM
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Quote Quote by hitssquad
Where did you get those figures? Willi wrote it takes 3 kilowatts-hours of pumping uphill to generate 2 kilowatt-hours of electricity when generating. That would be a storage efficiency of 67%.
Sorry, I was on Tsu's computer and the screen resolution threw me. I never saw that...but that seems impossibly high as a final number. I was assuming a 90% motor/generator efficiency, two ways, and then 20% for pumping, and 30% for turbine efficiency. Of course it depends on the turbines, but I think the best run around 66%, and this only accounts for one of four stages of the process.

It is not likely H2 will ever be as efficient as pumped storage. The problem with pumped storage is that there are limitation on places to pump to. We could do like the Soviets did and blast out reservoirs with hydrogen bombs, or we can settle for less-efficient storage technologies such as H2.
I don't follow. I cited the current, known, 5% well to wheels efficiency for H2 internal combustion. Its already being done.
hitssquad
#11
Jul18-05, 04:30 AM
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Quote Quote by Ivan Seeking
that seems impossibly high as a final number.
China is claiming the same thing.
power-technology.com/projects/tianhuangping

--
East China Electric Power's Tianhuangping pumped storage hydroelectric project is the biggest of its type in Asia. It [...] has a total installed capacity of 1,800MW.

[...]

The plant design achieved an overall cycle efficiency of 70%.
--


If we assume a 91.5% efficiency for the pump motor, a 91.5% efficiency for the pump, a 91.5% efficiency for the turbine, and a 91.5% efficiency for the generator, that would be an overall efficiency of 70.0945700625%.

Wikipedia's pumped-storage efficiency claims are even bolder than China's.
en.wikipedia.org/wiki/Pumped-storage_hydroelectricity

--
Between 70% and 85% of the electrical energy used to pump the water into the elevated reservoir can be regained in this process.
--
willib
#12
Jul18-05, 01:21 PM
P: 228
the point of my post was to illuminate you to the fact that we are wasting huge amounts of power , by pumping it up hill , just to let it flow back down , when demand is higher..
the only reason this is feasable is because power is cheaper at night ( for large users) ...
So they buy cheap power at night , and sell it back , at a hgher rate..
you would think that this would put a higher load on the overall system..
hitssquad
#13
Jul18-05, 01:55 PM
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Quote Quote by willib
The point of my post was to illuminate you to the fact that we are wasting huge amounts of power by pumping it up hill, just to let it flow back down when demand is higher.
In human enterprise, energy has time value. If you can parlay time-energy of a given value into time-energy of a greater value, your time-energy investment is not wasted.
willib
#14
Jul18-05, 03:39 PM
P: 228
If someone was to build a huge capacitor network to store the power at night..
and put it back during peak demand..
that would have much more efficiency , and make more sence than all the losses associated with pumping water up hill...
hitssquad
#15
Jul18-05, 03:52 PM
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Quote Quote by willib
a [...] capacitor network [...] would [...] make more sence than [...] pumping water up hill.
You mean it would be cheaper?
willib
#16
Jul18-05, 04:22 PM
P: 228
It would be like charging a battery, as opposed to
charging a battery while it is pumping water up hill ..
there is allways losses , even when charging a battery..
but not as much , as the topic of this discussion..
hitssquad
#17
Jul18-05, 04:31 PM
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Quote Quote by willib
there is allways losses [...] but not as much, as the topic of this discussion.
If the topic of this discussion is the saving of power no matter the price, wouldn't it be topical to mention that even more power could be saved by reducing base-load power production at night?
russ_watters
#18
Jul18-05, 04:47 PM
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Quote Quote by willib
the point of my post was to illuminate you to the fact that we are wasting huge amounts of power , by pumping it up hill , just to let it flow back down , when demand is higher..
the only reason this is feasable is because power is cheaper at night ( for large users) ...
So they buy cheap power at night , and sell it back , at a hgher rate..
you would think that this would put a higher load on the overall system..
It is not a waste in most cases. It is recovering energy that would normally be wasted if it weren't done. Someone else already explained this to you: you cannot just shut off a nuclear power plant at night so if you don't do something with that power, then it is wasted.
If someone was to build a huge capacitor network to store the power at night..
and put it back during peak demand..
that would have much more efficiency , and make more sence than all the losses associated with pumping water up hill...
Or you could use actual batteries. That's what regenerative breaking in hybrid cars does. The problem is that batteries and capacitors, in the size necessary for storage of grid power, would be extremely expensive.


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