# A power plant that uses more power than it generates

willib
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..!

Staff Emeritus
Gold Member
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
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.

Gold Member
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.

Gold Member
willib said:
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 criticize me (but not too hardly! )

Staff Emeritus
Gold Member
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.

Clausius2 said:
Have I translated rightly the term "Reactive Energy"?

H2 vs pumped storage

Ivan Seeking said:
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.

Gold Member
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.

Staff Emeritus
Gold Member
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.

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China's pumped-storage efficiency claims

Ivan Seeking said:
that seems impossibly high as a final number.
China is claiming the same thing.
http://www.power-technology.com/projects/tianhuangping/ [Broken]

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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%.
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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

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Between 70% and 85% of the electrical energy used to pump the water into the elevated reservoir can be regained in this process.
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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 feasible 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..

The time value of energy in human enterprise

willib said:
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
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 sense than all the losses associated with pumping water up hill...

willib said:
a [...] capacitor network [...] would [...] make more sense than [...] pumping water up hill.
You mean it would be cheaper?

willib
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..

willib said:
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?

Mentor
willib said:
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 feasible 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 sense 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.

willib
Russ , you wouldn't use batteries for regenerative braking..
you would use something that is able to store power quicker than a battery..

Willi, the Prius, the Insight, the Civic Hybrid, the Accord Hybrid, and the Lexus RX400h, among other vehicle models, all use lead-acid batteries in their regenerative braking systems. Eventually they might switch to ultracapacitors, though ultracapacitors have the problem of extremely low energy density relative to that of lead-acid batteries.

willib
why wouuld they use Batteries when this is available??
http://www.maxwell.com/pdf/uc/datasheets/BMOD2600-16.pdf

That .pdf says it holds 3.1 watt-hours per kilogram. Meanwhile, lead-acid batteries hold about 30 watt-hours per kilogram. That might be one reason.

That .pdf also says it holds 3.007 watt-hours per liter. Meanwhile, lead-acid batteries hold about 40 watt-hours per liter. That might be another reason.

http://www.nesscap.com/prod/Articles/AABC_UCDavis_200102.PDF [Broken]

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relative to batteries, the advantages of ultracapacitors as pulse power devices are high power density, high efficiency, and long shelf and cycle life. The primary disadvantage of ultracapacitors is their relatively low energy density (Wh/kg and Wh/l) compared to batteries limiting their use to applications in which relatively small quantities of energy are required before the ultracapacitor can be recharged.
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willib
The 21V module would consist of 8 cells, weigh
3 kg, and store 11 Wh of energy (8.4 Wh useable). The resistance of the module would
be 2.8 mOhm with a resultant calculated peak pulse power of about 17 kW. Two of the
21V modules would be used with the 36-42 V battery system. The weight of the
capacitor cells would be 6 kg, which would be much less than that of the batteries. The
capacitors could provide most of the peak power required from the system and the
batteries would recharge the capacitors during periods of relatively low system power
demand. The capacitors could also be used to recover energy during regenerative braking
if the vehicle was so equipped.
wow
for a rebuttle article , that one is pretty positive on the use of ultracaps in the automotive industry..

Mentor
I don't see anything in that quote that looks all that positive. Power numbers are meaningless, voltage and resistance numbers are meaningless - what matters is the 8.4 Wh, which is less than the battery-pack on my camcorder! I own a portable power station with, essentially, a motorcycle battery in it with a capacity of about 210 Wh.

willib
EDIT sorry double post

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Staff Emeritus
Gold Member
Gold Member

see http://www.energyvortex.com/energydictionary/reactive_power.html

The vectorial sum of Reactive power $$Q(VAr)$$ and True Power $$P(W)$$ gives the Apparent Power$$S(VA)$$. Reactive power is calculated as $$Q=UIsen\phi=XI^2$$ being X the reactance. It is used to magnetize the reactances inside electromagnetic machines, but it hasn't got any capacity of producing mechanical work. At night, when turbines are pumping the water uphill, the synchronous electrical motor acts as an "static compenser", injecting reactive power into the system.

willib
Since ultracapacitors use carbon i thought i would google carbon nanotubes and ultra capacitors..interrestingly , a lot showed up..
A matrix of vertically aligned carbon nanotube (CNT) has been investigated as a DLC electrode. Our analysis shows that this configuration can provide a combination of high power density (more than four orders of magnitude greater than fuel cells) and energy density (comparable to Li-Ion batteries). The significant enhancement in the achievable DLC power density derives from the high conductivity obtainable with CNTs, which in the limit of a few microns in length present ballistic conduction. The energy density improvement of a “nanotube enhanced electrode” is due to the higher effective surface area obtainable with a structure based on vertically aligned nanotubes over activated carbon
http://lees.mit.edu/lees/projects/cnt_ultracap_project.htm
Our analysis shows that the utilization of a matrix of vertically aligned CNTs as electrode structure, can lead to an ultracapacitor characterized by a power density greater than 100kW/kg (three orders of magnitude higher than batteries), a lifetime longer than 300,000 cycles, and an energy density higher than 60Wh/kg.

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willib
can lead to an ultracapacitor characterized by a power density greater than 100kW/kg (three orders of magnitude higher than batteries),
pretty cool huh Russ..

Inventing something and mass-producing it are different things, Willi. Your question was, "why wouuld they use Batteries when [ultracapacitors] are available"? The answer is, "Ultracapacitors are not available." However, ultracapacitors may soon be incorporated in a limited capacity in conjunction with batteries since they complement each other well, as the nesscap link you quoted pointed out.
http://www.nesscap.com/prod/Articles/AABC_UCDavis_200102.PDF [Broken]

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The capacitors could provide most of the peak power required from the system and the batteries would recharge the capacitors during periods of relatively low system power demand.
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willib
They sure are available, not in the power density i previously listed (from MIT), but they sure ARE available..
http://www.maxwell.com/pdf/uc/datasheets/BMOD2600-16.pdf
and you are correct ultracapacitors at this time , make an excellent complement with batteries..
Because they can absorb the energy from regenerative braking , very quickly..Much more quickly than a battery can..