Let's Talk About Energy Production

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Re: Let's Talk About Energy Production

Postby Azrael » Thu Feb 19, 2009 1:09 pm UTC

Zamfir wrote: This is basically the only way to store large amounts of energy.

Except there no actual energy storage involved. It's just a more efficient way to use the combined production capability.

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Re: Let's Talk About Energy Production

Postby BattleMoose » Thu Feb 19, 2009 1:27 pm UTC

Water in dams with hydroelectric capacity, is effecitvely stored electrical energy.

The Netherlands are able to export unneeded electricity (presumably produced from wind which they cannot control) to Norway, and then Norway is able to then not use the stored water in its dams to produce hydroelectricity. So water builds up behind the dam and can be used later. Its effectively a more efficient way of using traditional pumped storage, because it cuts out the inefficieny involved with pumping water uphill back into the dam.

Pumped storage, used mainly from economic reasons, uses cheap off peak electricity, to literally pump water back into the dam, so that the water can be released during peak periods to meet demand. Its very much cheaper than needing to build peaking plants for that extra needed capacity.

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Re: Let's Talk About Energy Production

Postby Azrael » Thu Feb 19, 2009 1:39 pm UTC

BattleMoose wrote:Water in dams with hydroelectric capacity, is effectively stored electrical energy.
Unburned oil (or any fuel) is effectively stored electrical energy too. But we don't consider it 'storing electrical energy' when we don't burn oil at Location A because the combined grid is being fed by Nuclear Plant B. That's using resources more efficiently.

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Re: Let's Talk About Energy Production

Postby BattleMoose » Thu Feb 19, 2009 2:20 pm UTC

You cannot take electricity and store it in the form of oil. You can take electricity and store it within pumped storage schemes.

Pumped Storage schemes and the scheme that they are organising here between the Netherlands and Norway by displacing hydropower with rewnewables, is effectively the only practical way to store large quantities of electrical power.

The capacity factors of hydroelectrical dams, are generally quite low, so if you arent using water to turn the turbines, because you are importing energy from the Netherlands, you are able to use that water to generate electricity at a later stage of your chosing. It's effectively "stored electrical energy."

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Re: Let's Talk About Energy Production

Postby cypherspace » Thu Feb 19, 2009 2:28 pm UTC

You cannot take electricity and store it in the form of oil. You can take electricity and store it within pumped storage schemes.
Yes, but you're saying that that isn't what's happening. If you were using the excess energy to pump water behind the dams to be used later, I'd agree with you. But really you're just using the resources available to create a more efficient distribution network, through regulation of supply source by demand. That's no different to turning off a coal plant at night and switching it back on during the day, say (regardless of practicalities involved).

To paraphrase yourself: If you're not using coal to heat water to turn the turbines, because you are using energy from a nuclear plant, you are able to use that coal to generate electricity at a later stage of your choosing. It's effectively "stored electrical energy".... except it's not. It's just using resources effectively.
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Re: Let's Talk About Energy Production

Postby Azrael » Thu Feb 19, 2009 2:50 pm UTC

Pumping schemes are close enough to storage. But being able to "shut off" hydroelectric dams is not even remotely "storage". I said the thing that isn't storage isn't storage.

You subsequently introduced something that *is* storage. But I haven't said that your orange is an apple, so you can stop insisting that your orange is an orange. We agree, it's an orange. But the apple is still an apple too.

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Re: Let's Talk About Energy Production

Postby BattleMoose » Thu Feb 19, 2009 3:02 pm UTC

cypherspace wrote:Yes, but you're saying that that isn't what's happening. If you were using the excess energy to pump water behind the dams to be used later, I'd agree with you.


Actually that is exactly what happens in pumped storage schemes. http://en.wikipedia.org/wiki/Pumped-sto ... lectricity

Now this isn't exactly whats going on in Norway. Norways electricity production is 99% from hydro. (PDF link) http://www.google.co.za/url?sa=t&source ... tGJk166D0w

So electricity they import, means they need to generate less, means water stores up behind the dams, which is effectively stored electricity which they can use at, well, whenever they want. Norway is actually a net exporter of electricity. Its actually a good buisness model, buy electricital at off peak times (cheap) and sell it later at peak times, profit! ;)

Even considering the scenario, if they had an equal mix of coal and hydro and importing random electricity from Netherlands.

They would have the choice to either generate less from coal, or from hydro, because they are importing. They would probably choose to reduce the output from hydro, for economic reasons. Hydro is a really fantastic peaking plant, and allows you to have a much greater level of control over your grid. Ideally you would like your coal plants to have a capacity factor of 100% (impossible but ideal scenario) and then use hydro for all the peaks. This ultimately would result in needing fewer coal fire power plants. (You could either have 5 plants at 80% capacity factor or 4 at 100%, clearly the latter is the cheaper option)

Hydro is great for peaking, for a variety for reasons, but mainly because it can go from 0% production up to 100% within a few minutes, no other electrical production facility offers this kind of load matching.

This is abit of a tricky mindset to put across.

Consider the hydro scenario, all the water that passes through the dam will produce electricity which will be used or exported. No matter how you choose to use the electricity thats imported, it doesnt actually effect how much energy is being produced by hydro, but only when. But it does reduce the amount of coal burned, even though when you are importing the electricity, the hydro is turned off and not the coal.

I don't think I am bringing this across at all well, its not somethign thats very easy to explain, so help from anyone else?

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Re: Let's Talk About Energy Production

Postby Azrael » Thu Feb 19, 2009 3:09 pm UTC

BattleMoose wrote:So electricity they import, means they need to generate less, means water stores up behind the dams, which is effectively stored electricity which they can use at, well, whenever they want. Norway is actually a net exporter of electricity.

This is the delineation that cypher and I are making: Not using Resource A (i.e. potential energy of water) because right now you're instead getting power from Resource B (insert technology type here) is not storage.

If you were using Resource B to create Resource A (i.e. pumping) only then would you be storing the energy from Resource B in Resource A.

Otherwise, you're just expending resources in a more efficient fashion.

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Re: Let's Talk About Energy Production

Postby mosc » Thu Feb 19, 2009 4:19 pm UTC

Aust-Agder
* Breive, Bykle
* Skarje, Bykle
Hordaland
* Aurland III (1979), 270 MW
* Jukla, 40 MW
* Kastdalen
* Nygard, Modalen
* Skjeggedal
Møre og Romsdal
* Mardal
* Monge
Nordland
* Tverrvatn
Rogaland
* Duge
* Hjorteland
* Hunnevatn
* Saurdal, 640 MW
* Stølsdal, 17 MW

Those are all PUMP hydro units that can pump water UP when they're not generating. Norway very much stores power. Can we stop this stupid back and forth?

Zamfir wrote:Here in Europe, HVDC is built more and more, but mainly (only?) for very long distance transport, so presumably the cost of still high. It is used more to build lines that were infeasible in the past because of losses, not to replace existing lines.
Look, I'm very happy y'all built a nice HVDC line but you need to understand that what you just said is lunacy. HVAC lines don't have high losses. 765 kv lines can handle huge distances with ease. The problem is not LOSSES. Stop using that word. You do not understand what you are saying.

The main reason to use HVDC in this application is angle mismatch across the line.
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Re: Let's Talk About Energy Production

Postby netcrusher88 » Thu Feb 19, 2009 5:38 pm UTC

mosc wrote:The main reason to use HVDC in this application is angle mismatch across the line.


I don't understand what that means. Is it something to do with the phases being out of sync?
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Re: Let's Talk About Energy Production

Postby mosc » Thu Feb 19, 2009 6:18 pm UTC

AC power is a waveform. We call the position in the wave the "phase angle". A phase angle difference is the difference between two waves positions at a given moment given identical frequency. In the power world, the frequency determines basically a wavelength. The wavelength is the distance at which the wave will have completed one cycle. In Europe, the frequency is 50hz which corresponds to a wavelength of 6000 km. If, say, an AC line was 200km long, you'd expect to see a ~12 degree separation from one end to the other. Keep in mind that is electrical distance, not physical distance. When the electrical distance starts to become different than the physical distance of the line, you get a mismatch. Remember there are very few power lines that go across water. Most of the lines take the long way around so the electrical distance between Holland and Norway is larger than the physical distance. Anyway, an AC line struggles with phase separation when the different ends are at different phase angles. DC however, has no frequency. There is no angle separation. It has an AC/DC transformer at both ends. This alleviates any worry over difference in phase angle from one end to the other. I hope my EE professor would approve but I probably messed up some part of this explanation.

HVDC lines are great for connecting isolated power grids which can even have different frequencies. It's also good for long distances for a variety of reasons. It's generally used in applications of long length because it's easier to deal with differences between the two ends. AC lines are not frequency isolated from each other when they are connected.

Anyway, I think we should try to refrain from these tangents? The only problem with the distribution of power is that the grid hasn't been able to grow as the population has. The "not in my backyard" attitude creates limited capacity as well as risk of power interruptions. That's somewhat unrelated to power generation though which is our topic here.
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Re: Let's Talk About Energy Production

Postby Sockmonkey » Thu Feb 19, 2009 8:46 pm UTC

Not to derail the topic or anything but what's the latest dirt on how close we are to making a viable, practical fusion plant? 20 years in the future? 50?

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Re: Let's Talk About Energy Production

Postby Sharlos » Thu Feb 19, 2009 10:51 pm UTC

Is there any reason they don't just put those big power lines underground? You couldn't always put it underground but alot of the time I don't see why not.

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Re: Let's Talk About Energy Production

Postby mosc » Thu Feb 19, 2009 11:41 pm UTC

Sharlos wrote:Is there any reason they don't just put those big power lines underground? You couldn't always put it underground but alot of the time I don't see why not.
There are lots of power lines underground already. Keep in mind they're absurdly expensive per mile and per unit of capacity. They're used sparingly and usually for short distances sometimes just a small part of a longer line. The voltage level is limited which also means it's not going to handle much capacity or long distance. The idea of something more industrial scale IE a long HVAC line underground is rather amusing to me. First off it would require a tunnel big enough to divert a major river. One of decent length might cost tens of billions of dollars if not more. Next, I can't imagine somebody getting permission to build something of that scale. Finally, I don't know how we'd operate it. The charging would be so utterly absurd that simply plugging it in might violate it's own thermal rating!

If you've ever seen a high voltage line, you'll note first that it has 3 phases. The next thing you should note is that the power lines themselves are suspended by insulators from the actual tower structure. The length of these insulators is directly proportional to the voltage. The higher the voltage, the further away any electrical ground needs to be. Now, with an underground line, you need to keep that distance from the actual line in all directions. This means at high voltage, you have a very large diameter tunnel. Remember that electrical lines are effectively giant electromagnets as well and interact with their other phases as well as the world around them. Wrapping them in a circle of electrical ground creates a very different dynamic than open air. Also, power lines generate heat (losses), especially as you load them down. They carry such immense power that even .1% losses means a shit ton of heat. They need cooling. When they are outside, that happens naturally. Underground, it's another headache. You can deal with all of this, it's just a question of cost and sacrificing flexibility. That's why it does see some use but is not conceivable to do for most things.

The Chunnel cost >$10B and was a mere 31 miles long. We have many power lines longer than that. It had 3 tunnels (like 3 phases) which were 25 feet, 25 feet, and 16 feet. The diameter of the short circuit range around a HVAC line is larger than that. You're talking about a project that makes connecting the UK to France look small for each one of these major lines. We have Hundreds of thousands of miles of lines in the US of that size.

Sorry to ramble. I'll not do that again.
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Re: Let's Talk About Energy Production

Postby netcrusher88 » Fri Feb 20, 2009 2:20 am UTC

Sockmonkey wrote:Not to derail the topic or anything but what's the latest dirt on how close we are to making a viable, practical fusion plant? 20 years in the future? 50?

Not counting solar power? :D

I think we're a long way - barring any breakthroughs, I don't think we can put an estimate on it. We understand the reaction, we just don't have the technology to contain it for any period of time, or without using more power than it produces.

mosc wrote:Sorry to ramble. I'll not do that again.

Please do, by all means. This is fascinating. I assume that HVDC is different in this respect (clearance)? Because an underwater line seems all but impossible if you need tunnels that big.
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Re: Let's Talk About Energy Production

Postby Comic JK » Fri Feb 20, 2009 4:42 am UTC

Sockmonkey wrote:Not to derail the topic or anything but what's the latest dirt on how close we are to making a viable, practical fusion plant? 20 years in the future? 50?


The smart money says that fusion power is about 20 years away, and will always remain so.
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Re: Let's Talk About Energy Production

Postby wisnij » Fri Feb 20, 2009 4:59 am UTC

Comic JK wrote:
Sockmonkey wrote:Not to derail the topic or anything but what's the latest dirt on how close we are to making a viable, practical fusion plant? 20 years in the future? 50?

The smart money says that fusion power is about 20 years away, and will always remain so.

Unless we get lucky and Bussard turns out to be right. Stock up on boron futures. 8)
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Re: Let's Talk About Energy Production

Postby cypherspace » Fri Feb 20, 2009 12:26 pm UTC

BattleMoose wrote:I don't think I am bringing this across at all well, its not somethign thats very easy to explain, so help from anyone else?

It's extremely easy to explain if you stop trying to call the hydroelectric dams which are not pumped storage "stored electrical energy". I have no issue with the rest of what you are saying. The efficient combination of resources from Holland and Norway is an excellent business model and should be used as an example of how to combine natural resources with the existing grid model in many countries. Just stop saying that Norway is "storing electrical energy" when in fact all it's doing is waiting to use that energy - because that is no different to "storing electrical energy" by not burning coal. It's misleading and gives a false impression of their model, because they are not using pumped storage systems. Do you see?
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Re: Let's Talk About Energy Production

Postby mosc » Fri Feb 20, 2009 4:38 pm UTC

cypherspace wrote:because they are not using pumped storage systems.
They are. I listed 15 sites in Norway that use pumped storage systems.
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Re: Let's Talk About Energy Production

Postby phonon266737 » Fri Feb 20, 2009 5:42 pm UTC

Hydroelectirc plants generally don't force all the water through the turbines, they use the dam to create very high pressures and divert water from the bottom through the turbine. Extra input bypasses the dam in a spillway (or something similar) - the idea is to keep the pressure at the turbine constant (the design pressure) so maximum efficiency can be achieved.

A hydroelectric plant designed to "drain" its reservoir would be a different beast (though it's an interesting idea) - upstream and downstream water levels would vary considerably during peak and off-peak times. I'm not sure how to go about considering the efficiency of such a design, but certainly the turbine will be more efficient when the outlet is exposed and the inlet is high (first switching the tubine on) than when the outlet is submerged and the level behind the dam is lower.

This is the alternative to simply maintaining normal operation, using excess electricity to pump the water back over the dam.

Sounds like a tough physics/engineering problem to solve - which is more efficient?

[Edit, on second thought, either system changes the downstream water level. Only the upstream water level is different, if the pump has a reservoir used only for that purpose, rather than pumping upsteam of the dam]

--> Just musing...does anyone remember the perpetual motion machine with the waterwheel that used the flow to carry buckets of water from downstream of the water wheel, upstream?

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Re: Let's Talk About Energy Production

Postby cypherspace » Fri Feb 20, 2009 6:47 pm UTC

mosc wrote:
cypherspace wrote:because they are not using pumped storage systems.
They are. I listed 15 sites in Norway that use pumped storage systems.

Not in what BattleMoose was referring to.
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Re: Let's Talk About Energy Production

Postby mosc » Fri Feb 20, 2009 9:38 pm UTC

cypherspace wrote:
mosc wrote:
cypherspace wrote:because they are not using pumped storage systems.
They are. I listed 15 sites in Norway that use pumped storage systems.

Not in what BattleMoose was referring to.

I totally disagree. He was referring to the concept that water in the reservoir is essentially storage. Which it is. If you pump it up there or if you simply let the rain/melt fill it up, you are still storing. And he's right. It's more efficient to NOT pump it up. That doesn't mean they can't. That doesn't mean they don't. It's just another scheme for storing energy.

The part I disagree with him on is that the demand can vary so greatly from day to night that it's often better to pump anyway since efficiency is not just about total power generation effort but the TIME at which you can deploy that stored resource. Greater interconnection to Europe should INCREASE pumping, not decrease it.

Fundamentally, the water level is a battery gauge. Whither you pump water in there or let it accumulate, it is "charging".
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Re: Let's Talk About Energy Production

Postby BattleMoose » Sat Feb 21, 2009 10:10 am UTC

The part I disagree with him on is that the demand can vary so greatly from day to night that it's often better to pump anyway since efficiency is not just about total power generation effort but the TIME at which you can deploy that stored resource. Greater interconnection to Europe should INCREASE pumping, not decrease it.


I was really looking at a more hypothetical scenario, regardless, glad at least someone got what I was saying. :/

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Re: Let's Talk About Energy Production

Postby phonon266737 » Sat Feb 21, 2009 3:43 pm UTC

http://www.nytimes.com/2009/02/21/business/21buy.html
Interesting article on the renewable energy stuff being purchased with the stimulus funds. Apparently a lot of solar panels and wind turbine are being imported, which is a bummer.
(If this belongs in N&A, I apologize)

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Re: Let's Talk About Energy Production

Postby Zamfir » Mon Feb 23, 2009 1:31 pm UTC

Whether you call it storage or more efficient use, I do think this question is very, very important for the future of electricity production, especially if we want to use more wind and solar energy.

Some more info http://www.abb.be/cawp/nlabb034/fc0bc18080b80021c1256f7300361f92.aspx about the Netherlands-Norway cable that sparked the discussion :) :

Mosc is right that the phase difference was one of the reasons to go for DC, perhaps even the main reason. But apparently, for a given price DC would also have roughly half the losses of AC ( 5-10% instead of 10-20%), so this was an important factor in itself. Presumably the info will be bit too positive about the benefits of DC, since they have chosen that, but I have heard form more general sources that in the range of hundreds of kilometers the power savings of DC become significant. By the way, it cost around 300 million euros for 600 km.

Azrael (and others) would have a point that "Unburned oil (or any fuel) is effectively stored electrical energy too. ", except that this isn't the case for ALL fuels, the Netherlands have some very large integrated coal plants, and those are slow to turn off, see for example here: http://www.berr.gov.uk/files/file20051.pdf
So when demand falls, the first thing we do is turn the gas plants off, "storing" in the form of gas :), then we stop importing (from Norway and elsewhere), and then we start sending electricity to Norway. Apparently, Norway uses so much electric heating that its consumption goes up in the nighttime, making it a nice place to sell our coal-generated electricity to. I am not sure if at any point Norway actually starts pumping.


This example is not just interesting because it shows how better grids can work to generate power more efficiently, but also because the same HVDC cables are going to be needed for off-shore wind farms. Wind turbines have the same phase problems as between two independent grids, and wind turbines connected directly to the grid can cause major headaches for the grid controllers. A really large wind park has to use some serious converting anyway to keep the phase problems under control, and the step to HVDC for long distance transport is then a lot easier to make.

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Re: Let's Talk About Energy Production

Postby Azrael » Mon Feb 23, 2009 1:49 pm UTC

Zamfir wrote:Azrael (and others) would have a point that "Unburned oil (or any fuel) is effectively stored electrical energy too." ...
So when demand falls, the first thing we do is turn the gas plants off, "storing" in the form of gas :)...

I'm assuming the smile is there because you know you've taken my words out of context and that you're saying they represent the exact opposite stance than there were originally used for? If not:

Azrael wrote:Not using Resource A because right now you're instead getting power from Resource B is not storage ... you're just expending resources in a more efficient fashion.

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Re: Let's Talk About Energy Production

Postby Zamfir » Mon Feb 23, 2009 2:29 pm UTC

Azrael, I think I more or less agree with you. Not using hydro power isn't really storage of electricity, and not using oil isn't really storage either.

On the other hand, the difference between substituting hydro on the one hand, and using the imported power to pump up water on the other hand is small, and I presume you agree that pumping would count as electricity storage. In my personal opinion, that makes substituting hydro power close enough to storage to be labelled as such. The same with oil or gas, assuming you store the oil you saved.

That's why the smiley: I thought that your best point was that if you label hydro substitution as storage, you should label oil substitution as storage as well. I know you wouldn't label either of them that way, but that's more semantics in my view.

I think the big divide is not between real storage and substitution, but between on the one hand real storage and substitution of flexible plants , and on the other hand substitution of inflexible plants such as some coal and nuclear plants. The latter has a significant cost, in both money and energy wasted.
Last edited by Zamfir on Mon Feb 23, 2009 2:31 pm UTC, edited 1 time in total.

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Re: Let's Talk About Energy Production

Postby mosc » Mon Feb 23, 2009 4:01 pm UTC

Azrael wrote:Not using Resource A because right now you're instead getting power from Resource B is not storage ... you're just expending resources in a more efficient fashion.
This is true except when Resource A naturally accumulates power on it's own. Coal fields don't grow when you leave them be. Water levels however, rise naturally. Running B instead of a hydro unit is in many respects storage. You are storing water. You are accumulating more potential energy and capability in your system. In other words, you're wrong.

But apparently, for a given price DC would also have roughly half the losses of AC ( 5-10% instead of 10-20%), so this was an important factor in itself.
BULLSHIT

Where do you get this crap from? 20%!??!?! Do you have any idea how large that is? How much HEAT you're talking about? Your numbers are insane.

AC. Lines. Don't. Have. Substantial. Losses. Enough already.

Citation: The ENTIRE distribution grid in the US is 7.2%. Keep in mind losses are reduced by increasing the transmission line voltage as well. When you're talking about grid wide losses, the vast majority of that is at lower voltage levels (nobody would be stupid enough to run 500,000 Volts to a house). Most customers in the US are hooked up by a fairly low voltage. This is where most of that 7.2% comes in. HOWEVER, an individual HVAC line is not going to have NEAR 7.2% losses. It's going to be 1% or so (No citation. Impedance data is not public domain). Also keep in mind that the more parallel paths you have, the lower the overall impedance. You can make a 0.1% loss network out of a bunch of 1% loss lines. You just need a lot of them.
Last edited by mosc on Mon Feb 23, 2009 4:15 pm UTC, edited 1 time in total.
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Re: Let's Talk About Energy Production

Postby Azrael » Mon Feb 23, 2009 4:04 pm UTC

mosc wrote:AC. Lines. Don't. Have. Substantial. Losses. Enough already.


Citing Things is a Good Idea.

EDIT: And you've already edited too.

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Re: Let's Talk About Energy Production

Postby Zamfir » Mon Feb 23, 2009 4:34 pm UTC

Mosc, another link, this time in English:
HVDC technology offers the unique capability to build long
underwater or underground cable transmission lines with
low losses. Traditional AC transmission systems with underwater
cables cannot be longer than about 60 - 100 km.
Beyond this the losses are prohibitive. The NorNed cable, with
a length of 580 km, has losses of only about 4 percent.


form: http://library.abb.com/global/scot/scot221.nsf/veritydisplay/c0bf1c6e436f9a5fc12575510053c89f/$File/POW-0048%20Norned%20Rev3%20LR.pdf

Form this, and Azrael's Wikipedia links, I think the important point is the underwater part. Apparently, AC has much higher losses when underwater than on land. On land, the point where AC losses become big enough to warrant DC conversion solely for efficiency reasons is in the hundreds of kilometers, far beyond what most electricity in the US ususally travels, but for underwater links this point comes much faster.

EDIT: You mention already that increasing the amount of lines will cut losses, which helps to explain the low loss figure for most networks. The main application for HVDC is for single connections between far away points, that's where the price aspect comes in. On such lines, it becomes economic to accept losses, instead of laying down more cables. So for most applications, the losses in AC transport are not relevant, except for large distance transport with only a single connection, and especially underwater.

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Re: Let's Talk About Energy Production

Postby mosc » Mon Feb 23, 2009 5:29 pm UTC

Why do AC lines have high losses and limited underwater? For the same reasons they have high losses and limited length underground. The limited length and high losses are because they're not using high voltage. Why can't they use high voltage? Because you need a shit ton of clearance. As I said, the higher the voltage the less the losses. If you have a very long low voltage AC line, it's not going to be practical. You can just build a bigger, higher voltage, line in MOST circumstances though. Underwater is a very special case. I never said they should use AC for this project, that would be moronic.

However, quit inferring that AC lines have high losses or that AC is stupid or that DC should replace AC. Please separate underwater and underground transmission from general transmission. They have very different challenges. You're taking a very specific case here and inferring a lot about transmission.

I'd also point out your source is ABB who built the line and they are putting out a press release here. It's not a discussion of HVAC vs HVDC in general use by any stretch. They don't get into the specific challenges of building a power line under water vs building one suspended from a tower. They don't cover why HVAC can't really be used in this application, they just compare HVDC to a low-voltage AC line because that's the only practical underwater AC line there is. Also, as I've said before on this, there are lots of reasons in this application to use DC even neglecting the underwater part. It's a very long line and the phase angle across the thing would be uncontrollable with AC. DC, that stuff goes out the window.

EDIT: When did this thread become about an underwater DC line in Europe?
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Re: Let's Talk About Energy Production

Postby Zamfir » Tue Feb 24, 2009 8:18 am UTC

Mosc, he brochure was from ABB because most non-ABB info was in Dutch, or Norwegian. Other sourcesgave pretty much the same info, and ABB builds AC lines too, so I guess they won't be that prejudiced. For the rest, I think most about HVDC has been cleared up by now.

One reason it is relevant is that for us Europeans, off-shore wind energy is only really viable solution to get large amounts of renewable energy, and cabling is one of the almost prohibitively expensive problems there. So for us, the Norway cable is an improtant "proof of concept": if that is feasible and affordable, than it is also feasible to build a cable to wind farms far in the North Sea. But I have heard that Texas currently doesn't have enough connection to other states to export its excess wind power, so the problem is more universal.

And the importance of a good grid is relatively new phenomenon in the thought about renewables. In the 1980's wind and solar were very much connected to a "live off the grid" mindset, and only in the last ten years or so have people realized that renewable energy will require more grid, not less (both of the AC and DC variety). For other aspects of energy production, we already know the story: wind has expensive maintenance, solar is expensive to produce, nuclear produces nasty waste, fossil fuels warm the globe and are running out, fusion doesn't exist yet. We can work hard to alleviate those problems, but in the short run a smarter grid can perhaps do more good. I have heard similar debates from the US too, so it is not just a European thing.

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Re: Let's Talk About Energy Production

Postby Mabus_Zero » Tue Feb 24, 2009 9:51 am UTC

Not to back up the discussion, but it seems we already explained away the problems of nuclear to NIMBY, and how it plays out in politics. So in what fashion, from the downright pessimistic to the overtly optimistic can we perhaps hope to frame the issue to, say, the American public, and how it is in fact the cheapest, most reliable, and safest alternative energy source that they can invest in? And please, I'm in no way discounting more natural solutions, such as wind, geothermal, photoelectric and hydroelectric arrays, only questioning their value in a pinch, and on demand. I'm of course advocating a chimeric system, as would suit my own individualistic philosophy.
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Re: Let's Talk About Energy Production

Postby Caaw » Fri Feb 27, 2009 1:18 am UTC

Does anyone have a link to information about specific city grids? Like a page where I can go see what the load was for Los Angeles for a six month period.

What exactly goes into improving efficiency? (from a technicians standpoint, or the guy responsible for the entire grid)

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Re: Let's Talk About Energy Production

Postby Azrael » Fri Feb 27, 2009 1:58 am UTC

For the seventh time or so: Nothing. 93% efficient is well above the threshold where efficiency increases have diminishing returns.

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Re: Let's Talk About Energy Production

Postby Zamfir » Fri Feb 27, 2009 7:44 am UTC

Caaw wrote:
What exactly goes into improving efficiency? (from a technicians standpoint, or the guy responsible for the entire grid)


This might be a misunderstanding: when people talk about improving the grid, they rarely mean reducing the losses in the existing grid, as those losses are small, and money is better spend on other savings.

When they want to improve the grid, they mostly want to make more connections in the grid over long distances, so that fluctuations in supply and demand can be spread over longer distances, and disruptions can be taken care of with more ease. They also can mean systems to make elctricity prices change on a short scale so that people and companies are encouraged to consume when there is over supply.

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Re: Let's Talk About Energy Production

Postby cypherspace » Fri Feb 27, 2009 3:33 pm UTC

Azrael wrote:For the seventh time or so: Nothing. 93% efficient is well above the threshold where efficiency increases have diminishing returns.

Not quite true - transformer standards and efficiencies have been continually increasing for years with lower and lower losses. American standards are actually higher than Europe's, I believe, and there's a lot of transformers that need replacing in the next few years. Their losses will be reduced substantially when they are replaced and the grid's efficiency will be improved. Although 93% efficient is a fantastic figure for any machine or system, even a 1% increase saves hundreds of millions of pounds. There's no specific drive towards any figure, but the natural evolution of the system is towards greater efficiency in general.
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Re: Let's Talk About Energy Production

Postby Comic JK » Sat Feb 28, 2009 7:46 am UTC

Mabus_Zero wrote:Not to back up the discussion, but it seems we already explained away the problems of nuclear to NIMBY, and how it plays out in politics. So in what fashion, from the downright pessimistic to the overtly optimistic can we perhaps hope to frame the issue to, say, the American public, and how it is in fact the cheapest, most reliable, and safest alternative energy source that they can invest in?


Reliable, I can agree with. Safest, I'm not so sure: nuclear power is much safer than people think, but comparing the minuscule danger of radiation release to the nonexistent danger of being whacked by a windmill blade, you can't say that small danger is safer than none at all. And as for 'cheapest'...citation needed? The cost to build a nuclear plant is enormous, the time and political will necessary are prodigious, and operating costs have never been as low as proponents have hoped. Solar power is even more expensive than nuclear, to be sure, but wind seems to cost less: http://peswiki.com/energy/Directory:Cents_Per_Kilowatt-Hour.
Our goals, as I understand them, are:
1. Prevent new fossil-fuel plants from being built
2. Install new alternative power, of all types
3. Shut down existing fossil-fuel plants
If a wide expansion of nuclear power is the fastest way to do this technically (unlikely; they take a long time to approve and build) or politically (even less likely; the public misinformedly hates them), then we should do it. But since more of the public is behind wind power, and it already works pretty well, that's where I think we should focus.
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Re: Let's Talk About Energy Production

Postby Zamfir » Sun Mar 01, 2009 6:59 pm UTC

Comic JK, those figures for wind are way too low. If they were correct, wind would be easily competitive with coal at the moment, and that is definitely not the case. Wind is almost exclusively build in countries with subsidies, and when a country stops its subsidies, the amount of wind power goes down fast again. The numbers I usually hear are 10 to 15 cents/kWh, and a bit higher for offshore wind. There is good hope that wind energy becomes competitive without subsidy in the future, but that point is not there yet.

The cost of nuclear energy is remarkably hard to determine, but unlike wind energy there are people interested in building plants just for profit, without subsidies, and France is a big exporter of cheap electricity, so presumably it is still cheaper than wind. On the other hand, demand for nuclear plants is not incredibly large, and a lot of it is in China. China is basically betting on all energy horses around, so it might well be that they would build nuclear just to get the experience, pretty much the way wind works in the West.

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Re: Let's Talk About Energy Production

Postby Comic JK » Sun Mar 01, 2009 7:18 pm UTC

I agree, they seemed a bit low to me too--on the other hand, I cited a source and you did not, so you should back up your assertion.
It could be that the figures that site gives are only for the production of the energy, which for wind is just maintenance costs, and not counting the amortized capital cost of the equipment. That would probably make the figures more reasonable. Another thing to consider is that wind power is cheap when it comes, which is usually less than a third of its technical capacity--that would explain why people would rather build coal plants, which you can run night and day at full load.
France's nuclear power grid, which is very impressive and I wish the US would emulate, was not built by private industry, but by the government and state-run companies, like most of French infrastructure. All of the nuclear plants in the US, while privately owned, have been built with government support. I don't know where people are building nuclear plants privately without subsidies, but I would like to hear about it if you would leave a link.
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