Welcome to the MacNN Forums.

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

You are here: MacNN Forums > Community > MacNN Lounge > Political/War Lounge > Long Haul: Oil vs Electricity for the Masses

Long Haul: Oil vs Electricity for the Masses
Thread Tools
MacNNFamous
Forum Regular
Join Date: Jul 2020
Status: Offline
Reply With Quote
Nov 9, 2020, 11:20 AM
 
Originally Posted by Doc HM View Post
It seems to me that governments tend end up running behind the curve. For example here in the UK they are still debating how to "save the High Street", how to invest in creating new high streets. That's over. In the main shops are over. I think we all get that. The High Street itself wasn't always there, and now it won't be again, or rather something entirely different will be, perhaps turning all the larger shops into flats and mixing in small immediate retail (ie milk, coffee, pharmacies - kind of like rural France.

Anyhoo - middle America, the big red bit in the middle. Huge resource and loads of space, but communities empty and hopeless ie fodder for far right false dreams.
I would think a huge investment in green energy and a green future could really turn these places around. All those huge farms have space and plenty of sun and also in places wind. Grow crops for ethanol and BioDiesel, give massive tax breaks to smaller startups pushing green tech and make them site themselves in the interior not all in California. Have a coherent and hopeful plan for a better future and unambiguously show the middle that they are part of it, vital even. Massively scale up connection in even rural places. Spend big. Imaginer the effect in terms of both actual investment and also the idea of a democratic administration actually investing in R areas. Actual investment not phoney government budgets where the money never makes it out of Washington. So far it seems all governments of both colour offer these communities is advice to move to the coasts.

In the main this worked for Germany where the west actually followed through on pushing money to the East. In the UK large parts of Labpurs traditional northern support fell to the Tories largely on promises of what they called "Levelling Up" Of course (as could have been predicted, the Tories have zero intention of actually doing anything other than continue to funnel money to their corporate and school buddies) but you can see how even the promise works wonders. You just have to actually do it. In the Tories case I would imagine their new Blue Wall will crumble immediately after the next election since they fail to deliver. (But that's another story).
It's a nice dream, but it's just SO BIG dude. Driving across Nebraska alone at 85-90mph takes almost 8 hours. The population density is just... almost nothing. So yeah, you could generate power there, but then you need to get it to places people actually use it.

Idk. I don't have answers for you. It seems really hopeless for a lot of it. The land is fertile, but there is no culture, it's homogenously white, and the education is appalling because there isn't much need for it.
     
Waragainstsleep
Posting Junkie
Join Date: Mar 2004
Location: UK
Status: Offline
Reply With Quote
Nov 9, 2020, 04:03 PM
 
Originally Posted by MacNNFamous View Post
It's a nice dream, but it's just SO BIG dude. Driving across Nebraska alone at 85-90mph takes almost 8 hours. The population density is just... almost nothing. So yeah, you could generate power there, but then you need to get it to places people actually use it.

Idk. I don't have answers for you. It seems really hopeless for a lot of it. The land is fertile, but there is no culture, it's homogenously white, and the education is appalling because there isn't much need for it.
I've heard about plans to turn the Sahara into a solar farm. Its doable. You guys pipe oil all the way from Alaska for goodness sake.
I have plenty of more important things to do, if only I could bring myself to do them....
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 9, 2020, 04:09 PM
 
Oil doesn’t drop voltage.
     
Waragainstsleep
Posting Junkie
Join Date: Mar 2004
Location: UK
Status: Offline
Reply With Quote
Nov 10, 2020, 04:33 AM
 
Originally Posted by subego View Post
Oil doesn’t drop voltage.
Kinda does. They leak and spill.
I have plenty of more important things to do, if only I could bring myself to do them....
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 10, 2020, 07:52 AM
 
Originally Posted by Waragainstsleep View Post
Kinda does. They leak and spill.
That can be fixed without rearranging the laws of physics.
     
Doc HM
Professional Poster
Join Date: Oct 2008
Location: UKland
Status: Offline
Reply With Quote
Nov 10, 2020, 08:02 AM
 
Originally Posted by subego View Post
That can be fixed without rearranging the laws of physics.
But really usually aren't. So leakage/spillage is just factored into the cost of the energy. just do the same with renewables.
This space for Hire! Reasonable rates. Reach an audience of literally dozens!
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 10, 2020, 08:07 AM
 
I’m going to stand by my claim they’re not really comparable.
     
Waragainstsleep
Posting Junkie
Join Date: Mar 2004
Location: UK
Status: Offline
Reply With Quote
Nov 10, 2020, 05:38 PM
 
Originally Posted by subego View Post
That can be fixed without rearranging the laws of physics.
Never heard of superconductors?

Originally Posted by Doc HM View Post
But really usually aren't. So leakage/spillage is just factored into the cost of the energy. just do the same with renewables.
Its not like we're going to run out of sun soon. Or wind.
I have plenty of more important things to do, if only I could bring myself to do them....
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 10, 2020, 06:22 PM
 
Originally Posted by Waragainstsleep View Post
Never heard of superconductors?
That work in the Sahara?

If we’re going to play that game, why not use fusion?
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 10, 2020, 10:23 PM
 
Originally Posted by subego View Post
That can be fixed without rearranging the laws of physics.
No, it cannot. It also costs energy to transport the gas or oil in the pipeline, after all, you need to accelerate masses and you have friction in the system as well. Moreover, you have losses due to leakage as well. So at the end of the day, the story is no different than energy losses involved in transporting electricity.
Originally Posted by subego View Post
If we’re going to play that game, why not use fusion?
Because there currently exists no fusion reactor on earth that sustains a burning plasma, much less a fusion power plant.
I don't suffer from insanity, I enjoy every minute of it.
     
Laminar
Posting Junkie
Join Date: Apr 2007
Location: Iowa, how long can this be? Does it really ruin the left column spacing?
Status: Offline
Reply With Quote
Nov 10, 2020, 10:31 PM
 
Originally Posted by OreoCookie View Post
No, it cannot. It also costs energy to transport the gas or oil in the pipeline, after all, you need to accelerate masses and you have friction in the system as well. Moreover, you have losses due to leakage as well. So at the end of the day, the story is no different than energy losses involved in transporting electricity.
Yes and no. Lift stations are usually powered by waste gas that would have been flared off anyway, so that's basically free energy.
     
Waragainstsleep
Posting Junkie
Join Date: Mar 2004
Location: UK
Status: Offline
Reply With Quote
Nov 10, 2020, 11:15 PM
 
Originally Posted by OreoCookie View Post
No, it cannot. It also costs energy to transport the gas or oil in the pipeline, after all, you need to accelerate masses
Alaska to the continental US is all downhill though.
I have plenty of more important things to do, if only I could bring myself to do them....
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 11, 2020, 01:41 AM
 
Originally Posted by Laminar View Post
Yes and no. Lift stations are usually powered by waste gas that would have been flared off anyway, so that's basically free energy.
There is no “free” energy. Powering lift stations with gas is no different than burning more gas to drive a steam turbine in order to compensate for transmission losses in wires. Of course, with renewables the extra energy is “free” as in free beer, too.

I take your point that stuff like that makes pipelines more efficient. Agreed. As a physicist, though, I just take issue with waving losses away for fossil fuels and insisting on their importance for renewables. From a practical perspective, operating costs will be more important than losses, especially since losses can simply be priced in. And the cost of spills could be tremendous.
I don't suffer from insanity, I enjoy every minute of it.
     
Laminar
Posting Junkie
Join Date: Apr 2007
Location: Iowa, how long can this be? Does it really ruin the left column spacing?
Status: Offline
Reply With Quote
Nov 11, 2020, 07:39 AM
 
Originally Posted by OreoCookie View Post
There is no “free” energy. Powering lift stations with gas is no different than burning more gas to drive a steam turbine in order to compensate for transmission losses in wires.
But it is different. In one case, you're paying for gas to fire your boilers to drive a steam turbine. You're not a fossil fuel processor, you're an electricity producer, so the gas costs you money.

In Alaska, the earth is literally forcefully vomiting up more gas than we can even capture. We either A) Burn it all off out the flare stack and produce nothing but a pretty light or B) use it to fire the lift compressors to boost pipeline pressure. I could never get those guys to bite on upgrades to the lift systems because there was literally zero ROI from efficiency increases since the fuel was free.
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 11, 2020, 09:04 AM
 
Originally Posted by Laminar View Post
But it is different. In one case, you're paying for gas to fire your boilers to drive a steam turbine. You're not a fossil fuel processor, you're an electricity producer, so the gas costs you money.
Sure, and renewables are also free in this sense.
Originally Posted by Laminar View Post
In Alaska, the earth is literally forcefully vomiting up more gas than we can even capture. We either A) Burn it all off out the flare stack and produce nothing but a pretty light or B) use it to fire the lift compressors to boost pipeline pressure. I could never get those guys to bite on upgrades to the lift systems because there was literally zero ROI from efficiency increases since the fuel was free.
I’d say that’s only because the damage to the environment isn’t priced in. Climate-wise, the gas is not free, it is causing emissions. Anyway, I think we are getting into the weeds. Sorry about that.
I don't suffer from insanity, I enjoy every minute of it.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 11, 2020, 10:57 AM
 
Originally Posted by OreoCookie View Post
Because there currently exists no fusion reactor on earth that sustains a burning plasma, much less a fusion power plant.
Just like there currently exists no superconductors that work in the Sahara.

Which was my point.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 11, 2020, 11:13 AM
 
Re: Saggy Oil Pipes that Leak

US pipelines carry a billion gallons of oil per day.

IOW, we could leak a billion gallons per year, and that’s still only 1/365th the total.

What actually gets leaked is a couple million gallons per year.
     
Laminar
Posting Junkie
Join Date: Apr 2007
Location: Iowa, how long can this be? Does it really ruin the left column spacing?
Status: Offline
Reply With Quote
Nov 11, 2020, 12:45 PM
 
Originally Posted by OreoCookie View Post
Sure, and renewables are also free in this sense.

I’d say that’s only because the damage to the environment isn’t priced in. Climate-wise, the gas is not free, it is causing emissions.
Very true in both cases. There are several reasons I don't work in O&G anymore. Given the current climate (economic and otherwise), I don't regret my decision one bit.
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 11, 2020, 08:00 PM
 
Originally Posted by subego View Post
Just like there currently exists no superconductors that work in the Sahara.

Which was my point.
You wrote that “pipelines don’t drop voltage”, “That can be fixed without rearranging the laws of physics,” claiming that oil and gas pipelines had an efficiency advantage. They don’t. They drop pressure rather than voltage, so I guess the first statement is technically correct. But you always have losses. Losses in pipelines at best cause additional emissions, and at worst pollute the environment in other ways.
Originally Posted by subego View Post
Re: Saggy Oil Pipes that Leak

What actually gets leaked is a couple million gallons per year.
For comparison, the Exxon Valdez lost 11 million gallons of oil, and this was a huge ecological disaster. If oil spills reach critical water supplies of a city or region, this will have severe consequences.
I don't suffer from insanity, I enjoy every minute of it.
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 11, 2020, 08:05 PM
 
Originally Posted by Laminar View Post
Very true in both cases. There are several reasons I don't work in O&G anymore. Given the current climate (economic and otherwise), I don't regret my decision one bit.
And I think it is economically smart, too. Demand for oil and gas is going to drop precipitously within the next 20 years, and changing industries before the change happens is smart. We have already reached an inflection point: renewables are the cheapest way to produce energy and the missing piece is a revamped electricity grid.
I don't suffer from insanity, I enjoy every minute of it.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 12, 2020, 12:04 AM
 
Originally Posted by OreoCookie View Post
...claiming that oil and gas pipelines had an efficiency advantage. They don’t.
Over long distances, which is what was being discussed, I think they do.

If I did my math right, the Keystone pipeline can push almost 60 billion joules worth of stored energy per second.

The longest transmission lines are 75% the length and top out at a little over 7 billion joules per second.

We can add whatever hidden costs we want, oil has near an order of magnitude worth of padding.
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 12, 2020, 02:32 AM
 
Originally Posted by subego View Post
Over long distances, which is what was being discussed, I think they do.
I should have been more precise in my last post: what irked me were the physics-related claims e. g. that oil doesn't drop voltage and that leaks and losses in pipelines are avoidable without having to break the laws of physics. As a physicist, I couldn't let that stand, thermodynamics tells us there are always losses. Can't help myself here, that hits too close to home
Originally Posted by subego View Post
If I did my math right, the Keystone pipeline can push almost 60 billion joules worth of stored energy per second.

The longest transmission lines are 75% the length and top out at a little over 7 billion joules per second.
That comparison is largely a hypothetical and forgets about physics. AFAIK there are no analogs of oil pipelines in existence yet, although several are under consideration and in various stages of planning. Germany plans a north-south “pipeline” to transport electricity produced in off-shore wind parks all the way to Bavaria. And there was an idea a few years ago to build solar farms in the Sahara and transport the energy to Europe, although I am not sure whether this will actually be built.

Electricity pipelines do not yet exist in the way that oil and gas pipelines do. But building some and some that are efficient it is no more or less ridiculous than building a pipe that is several thousand kilometers long and leaks very little. I think it'll be an inevitable piece in a modern electricity grid and could bring prosperity to sparsely populated, rural regions with little industry.

A second, very important point is that you assume that 100 % of the energy in the pipeline can be e. g. converted to electricity or motion. Looking at power plants, coal and oil power plants have an efficiency of about 33 %, gas seems to be 43ish % (hard to tell on the graph). ICUs in cars have efficiencies between 20 and 35 %. And you have to make gasoline in the first place, which also involves expending energy first. While this may seem nitpicky, this is relevant also when it comes to hydrogen. When you weigh the pros and cons of hydrogen-powered and battery-powered vehicles, these calculations enter in crucial ways.
Originally Posted by subego View Post
We can add whatever hidden costs we want, oil has near an order of magnitude worth of padding.
IMHO the relevant parameter is cost per J (or, equivalently, Wh). Pipelines aren't cheap and pipeline maintenance isn't cheap. In the US electricity grid about 5 % of the power is lost, which seems to include everything, including transmission and voltage conversion.


PS We currently don't have superconductors that work in the Sahara during the day, but physicists have recently discovered a superconductor that would work on a cold night in the Sahara. So it is not as ridiculously anymore to think of room temperature superconductors
I don't suffer from insanity, I enjoy every minute of it.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 13, 2020, 10:57 PM
 
@Oreo

If we’re talking about AC, over distances like the Keystone pipeline half the transmitted electricity doesn’t make it to the other end.

With the pipeline, 99.9% of what’s pumped makes it to the other end.

If we want to get down to the brass tacks of why we do one of these and don’t do the other, I think it’s fair to call that a laws of physics problem.

Now, for full disclosure, across most of my life AC accounted for effectively all transmission infrastructure, so I was only thinking in terms of AC. About 10 years ago, large scale DC projects started to get built, and they don’t have this problem.

So, I plead being out of date.






Buuuuuuuuut, if your room is the temperature of the Sahara... you should get an air conditioner.
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 13, 2020, 11:40 PM
 
Originally Posted by subego View Post
If we’re talking about AC, over distances like the Keystone pipeline half the transmitted electricity doesn’t make it to the other end.
… with the technology that is currently available. The fossil fuel industry has been at it for over 100 years and has received literally trillions of direct and indirect subsidies. Point being that pipelines have seen many decades worth of development, and electricity has historically not been transported regularly over similar distances.

Electricity has hitherto mostly been transported across a few 100 kms max, typically less. If you live in a bigger urban area, there’s probably at least one power plant nearby. And if you don’t need to transport electricity across such large distances, then you don’t develop technologies you don’t need. Using higher voltages that allow for more efficient long-range transport comes with trade-offs. Choosing AC over DC also makes sense if the voltages are not too super high.

I think at the end it all comes down to cost: how much does it cost to transport electricity from, e. g. the Sahara or the North Sea to the interior of Europe? If you include transmission cost, is it competitive? How cheap can you make it even if it is initially very expensive? I don’t know the answer when it comes to the Sahara, but plenty of countries use off-shore wind parks or, in case of Chile, put wind parks and solar parks in the desert in the north. Apparently even now, this is worthwhile across some distances.
Originally Posted by subego View Post
With the pipeline, 99.9% of what’s pumped makes it to the other end.

If we want to get down to the brass tacks of why we do one of these and don’t do the other, I think it’s fair to call that a laws of physics problem.
This 99.9 % neither includes the energy you need to transport the oil or gas nor the actual energy that you can use. You argued earlier that this energy is “free” because it cannot be used anyway, but the same is true of renewables, which are also free-once-you-build-and-operate-the-plant. The laws of thermodynamics tell us that when you just burn oil or gas, you can only convert a fraction of that into e. g. motion or electricity. And I think you’d still have to include the energy you need to transport the oil and gas, which is not free either. It should all be included in the energy balance.
Originally Posted by subego View Post
Buuuuuuuuut, if your room is the temperature of the Sahara... you should get an air conditioner.
That’s a common misconception about the desert. I wrote Sahara at night, and the average temperature at night is 15-20 degrees Celsius. In winter it can easily go below freezing. What’s harsh about the desert is not just the absolute temperature, but the temperature difference across a day.
I don't suffer from insanity, I enjoy every minute of it.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 14, 2020, 10:03 PM
 
Okay... let’s take this one bit at a time.

AC transmission of electricity started in the 19th century, as did oil pipelines. Pipelines are at best a few decades older.

The qualifier “over long distances” is in there. Is not the lack of this over 100+ years of AC transmission’s existence due to voltage drop?
( Last edited by subego; Nov 15, 2020 at 10:43 AM. )
     
andi*pandi
Moderator
Join Date: Jun 2000
Location: inside 128, north of 90
Status: Offline
Reply With Quote
Nov 14, 2020, 10:30 PM
 
We just watched a movie The Current War about Edison and Westinghouse and Tesla about the benefits of ac vs dc, which was distance.

Apparently Edison electrocuted an elephant and surreptitiously invented the electric chair to try to discredit ac currents as being too dangerous. (in the movie they used a horse "already on its way to the knacker" perhaps to be less disturbing?)

https://www.history.com/news/what-wa...f-the-currents
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 14, 2020, 11:05 PM
 
Elephants are union.
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 15, 2020, 11:21 AM
 
Originally Posted by subego View Post
The qualifier “over long distances” is in there. Is not the lack of this over 100+ years of AC transmission’s existence due to voltage drop?
The qualifier is important as is AC vs. DC: the advantage of AC is that you can relatively easily convert voltages up or down. Physics says that if you double the voltage, you gut the energy loss by a factor of 4 (it goes with the square). So for long-distance transport you want to use voltages that are as high as possible. But if the voltage is too high, you get so-called corona discharges, i. e. arcing between parts of the power line and something else, which shorts out the power line. That effect is much stronger with AC than DC, because with AC, electrons are being constantly accelerated back and forth. With DC, they are consistently pulled in one direction. Electricity transport over the now-typical distances does not require DC voltages, AC is fine for that. The total power losses across the grid are currently only 5 %, and that includes not just power transmission, but also stepping voltages up and down, etc. That’s why DC high-voltage power lines are much less developed as a technology than AC power lines.

Nevertheless, that’s why high-voltage dc power lines are more efficient and are being used for long-distance transport; apparently, the longest existing DC power line is in China, is 3,300 km long and has a capacity of 12 GW. Wikipedia quotes losses of about 3 % per 1,000 km, although the link for the citation no longer works and I couldn’t find out any of the details.
I don't suffer from insanity, I enjoy every minute of it.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 15, 2020, 11:32 AM
 
It’s a yes or no question.
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 15, 2020, 09:21 PM
 
Originally Posted by subego View Post
It’s a yes or no question.
No.
As I wrote in my longer response, the you can quarter losses by doubling the voltage. With AC lines, you can only double the voltage up to a certain point until the power line shorts out (intermittently or permanently). But since AC power has other advantages, the power grid was designed around this fact. Before renewables, on balance, AC won out, mostly because you can step up or step down voltages without solid state devices.

Renewables work best on a different kind of power grid, one that allows you to transport electricity over larger distances and where you shift power flexibly from one region to another. So now DC power lines become an interesting proposition, because they can significantly reduce losses by operating at higher voltages. DC power “pipelines” (aka electricity highways) only now become a technology that sees more and more adoption. And they allow you to economically transfer power over large distances.
I don't suffer from insanity, I enjoy every minute of it.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 15, 2020, 09:37 PM
 
Originally Posted by OreoCookie View Post
No.
Then what is the reason we do not use AC over long distances? Why do they use such high voltages in the first place?
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 15, 2020, 10:13 PM
 
Originally Posted by subego View Post
Then what is the reason we do not use AC over long distances?
I've explained that in my post that you quoted:
Originally Posted by OreoCookie
With AC lines, you can only double the voltage up to a certain point until the power line shorts out (intermittently or permanently).
And in my earlier post:
Originally Posted by OreoCookie
But if the voltage is too high, you get so-called corona discharges, i. e. arcing between parts of the power line and something else, which shorts out the power line. That effect is much stronger with AC than DC, because with AC, electrons are being constantly accelerated back and forth. With DC, they are consistently pulled in one direction. Electricity transport over the now-typical distances does not require DC voltages, AC is fine for that.
Originally Posted by subego View Post
Why do they use such high voltages in the first place?
I've also addressed this in the post you referred to:
Originally Posted by OreoCookie
… you can quarter losses by doubling the voltage.
I don't suffer from insanity, I enjoy every minute of it.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 15, 2020, 10:59 PM
 
Yes.

We want to up the voltage because the higher the voltage, the lower the losses.

We don’t use AC over long distances because even at the highest voltages possible without a short, there is too much loss.

Loss of what? It’s not voltage?
     
reader50
Administrator
Join Date: Jun 2000
Location: California
Status: Offline
Reply With Quote
Nov 15, 2020, 11:43 PM
 
Loss-of-energy can manifest several ways. For long-distance electric lines, it is measured in voltage drop, but can involve current loss too. As I understand it, the losses go to:

• I^2*R losses, which heat the lines. This is your regular cost of pushing current though imperfect conductors. Superconductors would fix this (and only this) loss. Seen as a voltage loss.
• The magnetic fields of the lines (if using AC) will cause induction heating in the (non-magnetic) countryside around the power lines. This should be proportional to the currents, which are as low as the power company can arrange, so this loss is small I expect. Would be seen as a voltage loss.
Coronal discharge. Very high voltage makes the air conductive, so some current leaks out of the wires. The missing power goes to heating the air, and generating small fluorescent lighting effects. Mostly a current loss, but I expect some voltage loss in creating the ionization.
• (rare) Idiots getting electrocuted climbing poles to steal electricity. Current loss. Power goes to cook meat.
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 16, 2020, 12:29 AM
 
Originally Posted by subego View Post
We don’t use AC over long distances because even at the highest voltages possible without a short, there is too much loss.
In safe operating conditions, the vast majority of the power loss just comes from transporting current at a given voltage across the wire. In the simplest picture, you just have to worry about ohmic resistance, R = U/I = voltage/current. Power = voltage * current. You can lower the resistance by increasing the cross section of the wires — up to a point. Otherwise the wires would become too heavy. Like reader correctly points out, there is additional resistance when you are dealing with AC currents, but at least I feel a proper explanation would lead us into the weeds. But this is another plus in the book of DC lines.

Power lines use the surrounding air as an insulator. If the AC voltage is too high, it can make the air conducting in the same way a lightning does and then you short out the power line. Not only does that leak a lot of power, and is also unsafe and like you say can lead to shorts. This would add to the ohmic resistance. And at a certain point your AC power line would simply cease to function as a power line, and at that point we would probably no longer speak of losses but simply a ginormous shorted circuit. Switching on a power line with high-enough AC power would just ionize the air and create an arc at some place, a small lightning that bridges the air gap from power line to ground. I reckon it would happen near a tower where the current can travel to a steel structure via the air.

You can use DC lines at much, much higher voltages without corona discharges becoming a significant problem, which means you can transport power over much larger distances with lower loss. Like reader explained, the power loss is proportional to the square of the current or, equivalently, proportional to 1/voltage^2, so all other things being equal doubling the voltage reduces power losses by a factor of 4.

A regular high-voltage power line operates at about 115-140 kV. The highest voltage DC lines can use in excess of 1,000 kV. So for simplicity let’s use a factor of 8 between the two: the power loss over the same distance with the 1,000 kV DC line is 1/64th of that of the typical AC line. Of course, you do have some additional losses when you convert the DC voltage into AC voltage, but still, at least in transport, you save a lot of losses. Note that solar does and and wind power can be set up to generate DC voltage directly, so you would not necessarily have to have two AC-DC conversions but just one.

Note that this is also why 220~240 V circuits are inherently more efficient than 110 V circuits. Japan uses 110 V and American plugs, unfortunately, which means we can easily trigger the circuit breaker by just running the AC and cooking at the same time. Appliances are also significantly less powerful (e. g. ovens, washing machines and vacuums).

Lastly, at least in Europe the typical distances for planned or existing high-voltage DC power highways/pipelines is a few hundred kilometers:


So the losses would be even smaller. I should also mention that in Europe there is a shared, European electricity grid and electricity can be bought and sold. This also makes the network more robust as excess energy can be transmitted to a region that currently has very little. But unlike oil, the electricity does not actually have to travel all the way from one end to the other, like oil.
Originally Posted by subego View Post
Loss of what? It’s not voltage?
It is not very good to think of voltage drops, because voltage drops across a conductor no matter how small the resistance is. What matters is energy loss, i. e. the amount of leak current flowing multiplied with the voltage.
I don't suffer from insanity, I enjoy every minute of it.
     
Spheric Harlot
Clinically Insane
Join Date: Nov 1999
Location: 888500128, C3, 2nd soft.
Status: Offline
Reply With Quote
Nov 16, 2020, 07:16 AM
 
Originally Posted by OreoCookie View Post
From a practical perspective, operating costs will be more important than losses, especially since losses can simply be priced in. And the cost of spills could be tremendous.
Since those spills often enough happen in places where there is no real value placed on the environment (or human lives), they have been comparatively cheap to what they actually SHOULD cost the companies.

See https://en.wikipedia.org/wiki/Enviro...he_Niger_Delta for an example.
     
Spheric Harlot
Clinically Insane
Join Date: Nov 1999
Location: 888500128, C3, 2nd soft.
Status: Offline
Reply With Quote
Nov 16, 2020, 07:19 AM
 
Originally Posted by reader50 View Post
(rare) Idiots getting electrocuted climbing poles to steal electricity. Current loss. Power goes to cook meat.
(Emphasis mine)

Well-done!
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 17, 2020, 11:51 PM
 
Originally Posted by OreoCookie View Post
It is not very good to think of voltage drops...
I’m forced to think in voltage drops because there’s no other way to know how much power I can get from the circuit without knowing the voltage at the load.

I can’t know the voltage at the load without calculating the voltage drop in the transmission lines due to resistance or impedance.

I’ve never seen voltage drop shaming before. 2020 continues to surprise.
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 18, 2020, 01:54 AM
 
Originally Posted by subego View Post
I’m forced to think in voltage drops because there’s no other way to know how much power I can get from the circuit without knowing the voltage at the load.
The voltage drop together with the current will give you the power loss. But thinking in terms of voltage drops will lead to seeming contradictions: if you double the voltage, but keep the power constant, then the voltage drop will double, but the power (= voltage times current) drop will be 1/4th, i. e. smaller, because the current will by 1/4 = (1/2)^2.
I don't suffer from insanity, I enjoy every minute of it.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 18, 2020, 03:20 AM
 
That’s not a contradiction.

Also, if we double the voltage at the generator, unless we double the generator output at the same time, the current for the entire circuit is cut by half.

Generator output isn’t normally something we get to casually double, especially with a renewable.
     
OreoCookie
Moderator
Join Date: May 2001
Location: Hilbert space
Status: Offline
Reply With Quote
Nov 18, 2020, 04:26 AM
 
Originally Posted by subego View Post
That’s not a contradiction.

Also, if we double the voltage at the generator, unless we double the generator output at the same time, the current for the entire circuit is cut by half.
No, this is precisely the point of high-voltage lines: the generator gives out power P = U*I, which you can convert into any combination of voltage U and current I. Assuming everything is AC for the moment, you can change the voltage and current with transformers to your liking without changing power (I'm ignoring losses during the transformation process for simplicity). This is then transmitted over power lines. Generators are not directly connected to power lines. And because of what I and others have written earlier, higher voltages will reduce transmission losses (until sparks come flying).

If you have a simple circuit that entirely operates on the same voltage (e. g. you think of the voltages lines as a resistor and then the consumer as another resistor that is in series), then it makes sense to think of voltage drops since the voltages need to add up U_{tot} = U_{lines} + U_{consumer}, and the voltages are proportional to the relative contribution to the total resistance. This simple computation fails when you convert voltages before or after the transmission via the power lines. That is because the formula only works if the current that's flowing through the circuit is the same for both resistors. When you use a transformer, though, you trade magnitude of current for magnitude of voltage.

What is still true, though, is how much power each of these circuits consume relative to one another.
Originally Posted by subego View Post
Generator output isn’t normally something we get to casually double, especially with a renewable.
You do not double the generator output, you use a transformer or something functionally equivalent to convert one voltage-current combination into another.
I don't suffer from insanity, I enjoy every minute of it.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 18, 2020, 04:51 AM
 
We can’t do it to our liking due to conservation of energy.

The product of voltage and current going into an ideal transformer will equal the product of voltage and current going out of the transformer.

If we double the voltage, we halve the current.
     
Doc HM
Professional Poster
Join Date: Oct 2008
Location: UKland
Status: Offline
Reply With Quote
Nov 18, 2020, 04:59 AM
 
To broaden the picture slightly it seems that the only useful endpoint is the amount of energy that is moved form one place to another, since at the end of the day that's what we need, energy and the whole life cost of the energy.
I would argue that consistently the fossil fuel industry focuses on the apparent efficiency of pipeline trasport vs long distance AC transmission and smugly folds its arms.

There are very many additional factors to consider (not leat environmental ones - that have traditionally been valued at zero). When renewables are planned suddenly its horrific the damage they may (or may not) do to birds or snails or whatever while the entire Niger Delta sinks into a slurry of petrochemical sludge, whole countries are mired in oil money corruption, wars are fought and refought over pipeline routes and suddenly the whole of the Arctic Circle is up for grabs).

But hey, lightbulbs
This space for Hire! Reasonable rates. Reach an audience of literally dozens!
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 18, 2020, 06:32 AM
 
Even if we could get the oil industry to take their thumb off the scale, we have several bajillion dollars of sunk cost in oil infrastructure, and it excels at transporting energy across truly enormous distances in a way electricity does not.
     
Laminar
Posting Junkie
Join Date: Apr 2007
Location: Iowa, how long can this be? Does it really ruin the left column spacing?
Status: Offline
Reply With Quote
Nov 18, 2020, 07:49 AM
 
Originally Posted by subego View Post
I’ve never seen voltage drop shaming before. 2020 continues to surprise.
What will the SJWs go after next??

Originally Posted by subego View Post
Even if we could get the oil industry to take their thumb off the scale, we have several bajillion dollars of sunk cost in oil infrastructure, and it excels at transporting energy across truly enormous distances in a way electricity does not.
Maybe I missed this part in all of the back and forth, but why is it important for renewables to be able to transmit energy over extremely long distances? I thought some of the benefit of renewables was the decentralization of the grid, where power sources could be smaller, spread out, and closer to point of use. O&G has to be able to transport over long distance because we can't control where it's sourced from, the earth decided that millions of years ago. And as we suck dry all of the easy-to-access resources, we have to get more remote and transmit over longer distances, hence the huge investment in LNG over the past decade.

But wind, solar, geothermal, etc. can be captured just about anywhere with varying levels of effectiveness, so we don't really have to care about how easy it is to transmit electricity 2000 miles away, right?
     
Spheric Harlot
Clinically Insane
Join Date: Nov 1999
Location: 888500128, C3, 2nd soft.
Status: Offline
Reply With Quote
Nov 18, 2020, 08:51 AM
 
Originally Posted by subego View Post
Even if we could get the oil industry to take their thumb off the scale, we have several bajillion dollars of sunk cost in oil infrastructure, and it excels at transporting energy across truly enormous distances in a way electricity does not.
It also excels at spectacularly ruining extraordinarily large ecosystems and geographies when it fails at doing so, and while it excels at transporting energy, this does not come without losses, which constantly need to be made up for.

By contrast, renewable energy may lose more energy in transfer, but making up for that loss is literally free, once the infrastructure is built at the appropriate scale.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 18, 2020, 01:41 PM
 
Originally Posted by Laminar View Post
Maybe I missed this part in all of the back and forth, but why is it important for renewables to be able to transmit energy over extremely long distances?
What sparked (heh) the discussion was putting a giant solar farm in the Sahara.
     
Doc HM
Professional Poster
Join Date: Oct 2008
Location: UKland
Status: Offline
Reply With Quote
Nov 18, 2020, 02:07 PM
 
Originally Posted by subego View Post
What sparked (heh) the discussion was putting a giant solar farm in the Sahara.
Or using renewables as a way to revitalise the economy of the centre of America where there is a lot of sun and wind.
This space for Hire! Reasonable rates. Reach an audience of literally dozens!
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 18, 2020, 10:40 PM
 
Originally Posted by Doc HM View Post
Or using renewables as a way to revitalise the economy of the centre of America where there is a lot of sun and wind.
Revitalize? No one lives there.
     
subego
Clinically Insane
Join Date: Jun 2001
Location: Chicago, Bang! Bang!
Status: Offline
Reply With Quote
Nov 18, 2020, 11:05 PM
 
Originally Posted by Spheric Harlot View Post
It also excels at spectacularly ruining extraordinarily large ecosystems and geographies when it fails at doing so, and while it excels at transporting energy, this does not come without losses, which constantly need to be made up for.

By contrast, renewable energy may lose more energy in transfer, but making up for that loss is literally free, once the infrastructure is built at the appropriate scale.
It all boils down to supply and demand.

We tolerate environmental damage from oil because there’s a massive demand for it which renewables can’t fill.

There will come a time when, say, long-haul trucking can run on electric. We’re not even close to there yet. I’m not sure what we’re supposed to do in the meantime.
     
 
Thread Tools
 
Forum Links
Forum Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Top
Privacy Policy
All times are GMT -4. The time now is 06:37 PM.
All contents of these forums © 1995-2017 MacNN. All rights reserved.
Branding + Design: www.gesamtbild.com
vBulletin v.3.8.8 © 2000-2017, Jelsoft Enterprises Ltd.,