Electrics vs. Diesels
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montana mike
Conductor
If the railroads eventually switch to Natural gas to power their engines it may be a mute point. I know BNSF is testing this right now and the initial reports have been very favorable.
jis
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And I don't think there is an universal answer to that questions. It depends on many many factors including traffic density, nature of traffic, relative cost of electricity vs. the fule under consideration at the point of use. Etc. etc.
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George Harris
Engineer
The problem with electric operation is the huge cost to get the power system into place. Talk to anyone involved in electric power transmission, and you will find that there are very large line losses in long distance transmission of electricity. If the power plants for the electric system and the engines are both running on natural gas, there may be no advantage whatsoever in electric operation in freight. Teh basic ability of a locomtive to haul is in many instances based on weight on powered axles. At low speeds you can still provide more power from a diesel than can be transferred to the rail.
For passenger service, that is a different story as acceleration beyond the lowest speed range is based on power available, not weight on driving axles.
The other is the issue of power from renewable resources. Obviously not practical except with electrification. But, with power generated by gas or oil, there is nothing gained there by electrification. We have got to go to hydropower or geothermal. I do not count wind or solar due to their limitations, daytime for the one, and erratic nature of winds for the other.
For passenger service, that is a different story as acceleration beyond the lowest speed range is based on power available, not weight on driving axles.
The other is the issue of power from renewable resources. Obviously not practical except with electrification. But, with power generated by gas or oil, there is nothing gained there by electrification. We have got to go to hydropower or geothermal. I do not count wind or solar due to their limitations, daytime for the one, and erratic nature of winds for the other.
Ryan
Court Jester
Of course there is - one big power plant is still more efficient than a bunch of little ones getting carried around (even when you account for line losses).
Don't be so quick to discount them, they can both still provide a heck of a lot of energy, and technologies such as molten salt and pumped hydro can help even out the power supplied.
N
Nathanael
Guest
Electric is always substantially cheaper to operate.
The cost of maintaining the system of overhead wires is large enough that the cost of operation + maintenance for electric may be higher than for electric for a line seeing only a few trains a day.
However, the big issue, as Mr. Harris says, is the cost of building the electrification system in the first place, which is very large. The cost savings from operations aren't usually large enough to cover the cost of building the electrification in the first place, except on lines with intensive service (different people have put the breakpoint for "intensive" service in different places; I've heard everything from 1 train/hour to 4 trains/hour).
(Remember that the cost of building the electrification has to be borne upfront, while the savings comes in over many years -- when you add in the cost of interest on the bonds issued to fund the electrification, then you start finding that the savings don't pay for it. If you have nothing better to do with a huge pile of cash, of course, electrification will always *eventually* pay for itself, but if the payback time is 100 years there would probably be something better to do with the cash.)
There is another nasty issue: it's a pain to have a partly-electrified line. Amtrak has a bunch of delays in its schedule from engine changes between electric and diesel, you'll note. So it turns out that the payback is a lot better from electrifying a whole system than from electrifying a few pieces of it.
BNSF did a study on electrification which has not been made public, but there were some leaks from it. The conclusions leaked were:
(A) it was not cost-effective to electrify part of the system; if they electrified, they should electrify *everything*;
(B) electrification was not cost-effective at then-current diesel prices, but would be if some (unspecified) higher diesel price were to persist. The higher price was never stated but was implied to be not that far above the then-current price. Of course, since then diesel prices have dipped for several years.
For reference, the advantages of electrification are many, and more than George Harris realizes.
(1) Small thermal power plants are far less efficient than large ones. Yes, it *is* more efficient to power an electric engine from an overhead line powered by a big diesel-powered power plant than to run a diesel locomotive, because the big power plant is more efficient than the one in the locomotive.
(2) Power line transmission losses are relatively small, contra Mr. Harris. They are practically irrelevant compared to the immense costs of transporting fuel such as diesel by truck, or even natural gas by pipelines. (Pipelines cost a fortune to maintain compared to power lines.) It is generally much more efficient to locate a thermal power plant next to the source of fuel (the mine or whatever) and move the electricity, than it is to locate the power plant next to the place where the energy is used and move the heavy, heavy fuel.
(3) Carrying the fuel and engine for a diesel locomotive is *dead weight*. Not carrying the power plant means you aren't moving that stuff around -- a great savings.
(4) Solar (with energy storage) has much, much larger potential than Mr. Harris thinks -- it's getting very cheap to install, it has minimal operations costs, and there's enough solar energy to power pretty much everything. Yes, storing energy at night is a big issue, but even if you could power everything with solar during the day (switching to gas at night, say), that would be a *huge* improvement.
Natural gas locomotives are a dead end. They'll work fine, of course. But then the price of natural gas will go up and they won't be a good choice. Fracking is only suppressing the price temporarily; there simply isn't that much gas to be gotten by fracking, as most fracked fields run out in 5-10 years. (Fracking for gas -- as opposed to liquids -- is actually unprofitable now and has been for quite a while. The current gas fracking companies have a business model based around land-flipping and violation of environmental standards.) Housing insulation and people switching their heating from gas to electricity will provide somewhat more sustainable downward pressures on the natural gas price, but the use of natural gas to provide peaking electricity generation will provide a countervailing upward pressure. It is also in demand for stoves and industrial uses which puts a floor on the demand.
Meanwhile the price of electricity is being held down by several things, all of which will continue. Housing insulation (the gains which can be made from this are on the order of 90%); the swap-out of incandescent lighting for LEDs (which use <1/10 as much energy), which is moving slowly but continuously; other efficiency improvements which are being driven by the desire to maximize battery life on gadgets; the continuous deployment of small-scale solar, which shows up in the electric utilities' reports as reduced demand; and large-scale solar, which now has a levelized cost cheaper than coal in some (sunny) regions. Counteracting that is the upward pressure from the deployment of electric cars, but that's going much slower than the downward price pressures. Other upward pressures are from more electronic gadgets (cancelled out by efficiency gains), from people switching heating *to* electric (but they usually make energy-efficient improvements to their house at the same time, cancelling that out), and from increase in number of households (which is slow and even stalling out).
There's some serious weirdness with electricity pricing in a few regions where the monopoly utility is charging far-above-market prices to pay for 40-year-old nuclear power plants and crazy stuff like that, but don't let that confuse you. (Though if you're running a railroad, be careful to locate your supply substations outside those regions.)
My analysis of the trajectory of energy prices says that the $$$ advantages of electric over fuel will get better and better for several decades at least. The potential bankruptcy of a number of utility companies complicates things -- better to have your own solar.
The cost of maintaining the system of overhead wires is large enough that the cost of operation + maintenance for electric may be higher than for electric for a line seeing only a few trains a day.
However, the big issue, as Mr. Harris says, is the cost of building the electrification system in the first place, which is very large. The cost savings from operations aren't usually large enough to cover the cost of building the electrification in the first place, except on lines with intensive service (different people have put the breakpoint for "intensive" service in different places; I've heard everything from 1 train/hour to 4 trains/hour).
(Remember that the cost of building the electrification has to be borne upfront, while the savings comes in over many years -- when you add in the cost of interest on the bonds issued to fund the electrification, then you start finding that the savings don't pay for it. If you have nothing better to do with a huge pile of cash, of course, electrification will always *eventually* pay for itself, but if the payback time is 100 years there would probably be something better to do with the cash.)
There is another nasty issue: it's a pain to have a partly-electrified line. Amtrak has a bunch of delays in its schedule from engine changes between electric and diesel, you'll note. So it turns out that the payback is a lot better from electrifying a whole system than from electrifying a few pieces of it.
BNSF did a study on electrification which has not been made public, but there were some leaks from it. The conclusions leaked were:
(A) it was not cost-effective to electrify part of the system; if they electrified, they should electrify *everything*;
(B) electrification was not cost-effective at then-current diesel prices, but would be if some (unspecified) higher diesel price were to persist. The higher price was never stated but was implied to be not that far above the then-current price. Of course, since then diesel prices have dipped for several years.
For reference, the advantages of electrification are many, and more than George Harris realizes.
(1) Small thermal power plants are far less efficient than large ones. Yes, it *is* more efficient to power an electric engine from an overhead line powered by a big diesel-powered power plant than to run a diesel locomotive, because the big power plant is more efficient than the one in the locomotive.
(2) Power line transmission losses are relatively small, contra Mr. Harris. They are practically irrelevant compared to the immense costs of transporting fuel such as diesel by truck, or even natural gas by pipelines. (Pipelines cost a fortune to maintain compared to power lines.) It is generally much more efficient to locate a thermal power plant next to the source of fuel (the mine or whatever) and move the electricity, than it is to locate the power plant next to the place where the energy is used and move the heavy, heavy fuel.
(3) Carrying the fuel and engine for a diesel locomotive is *dead weight*. Not carrying the power plant means you aren't moving that stuff around -- a great savings.
(4) Solar (with energy storage) has much, much larger potential than Mr. Harris thinks -- it's getting very cheap to install, it has minimal operations costs, and there's enough solar energy to power pretty much everything. Yes, storing energy at night is a big issue, but even if you could power everything with solar during the day (switching to gas at night, say), that would be a *huge* improvement.
Natural gas locomotives are a dead end. They'll work fine, of course. But then the price of natural gas will go up and they won't be a good choice. Fracking is only suppressing the price temporarily; there simply isn't that much gas to be gotten by fracking, as most fracked fields run out in 5-10 years. (Fracking for gas -- as opposed to liquids -- is actually unprofitable now and has been for quite a while. The current gas fracking companies have a business model based around land-flipping and violation of environmental standards.) Housing insulation and people switching their heating from gas to electricity will provide somewhat more sustainable downward pressures on the natural gas price, but the use of natural gas to provide peaking electricity generation will provide a countervailing upward pressure. It is also in demand for stoves and industrial uses which puts a floor on the demand.
Meanwhile the price of electricity is being held down by several things, all of which will continue. Housing insulation (the gains which can be made from this are on the order of 90%); the swap-out of incandescent lighting for LEDs (which use <1/10 as much energy), which is moving slowly but continuously; other efficiency improvements which are being driven by the desire to maximize battery life on gadgets; the continuous deployment of small-scale solar, which shows up in the electric utilities' reports as reduced demand; and large-scale solar, which now has a levelized cost cheaper than coal in some (sunny) regions. Counteracting that is the upward pressure from the deployment of electric cars, but that's going much slower than the downward price pressures. Other upward pressures are from more electronic gadgets (cancelled out by efficiency gains), from people switching heating *to* electric (but they usually make energy-efficient improvements to their house at the same time, cancelling that out), and from increase in number of households (which is slow and even stalling out).
There's some serious weirdness with electricity pricing in a few regions where the monopoly utility is charging far-above-market prices to pay for 40-year-old nuclear power plants and crazy stuff like that, but don't let that confuse you. (Though if you're running a railroad, be careful to locate your supply substations outside those regions.)
My analysis of the trajectory of energy prices says that the $$$ advantages of electric over fuel will get better and better for several decades at least. The potential bankruptcy of a number of utility companies complicates things -- better to have your own solar.
Are there truly any diesel powered locomotives (the diesel engine directly turns the wheels)?
I thought all of today's train locomotives were driven by electric motors, just some also have their own diesel powered electric generator on-board.
jis
Permanent Way Inspector
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Administator
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Gathering Team Member
Would you consider the Vossloh diesel-Hydraulics or the Indian Suri transmission which is a combo of hydraulic and mechanical to be truly diesel powered. Even the diesel-electrics IMHO are diesel powered since the only source of power in them is diesel. The electric part is just the transmission coupling the on board power source to the driving wheels.
It of course starts getting complicated in hybrid situations where you can have a plug-in with an additional on board ICE power source etc. too.
battalion51
Engineer
The DMU model that was put out by Colorado Railcar about ten years ago used a diesel engine tied to a transmission to deliver its traction power. The challenge with this model is that it significantly changes the way Engineers operate their train versus a traditional diesel-electric model, and therefore doesn't provide the same acceleration/time keeping.
OlympianHiawatha
Engineer
The Budd Rail Diesel Cars (RDCs) that were used by many American Railroads for short haul light volume passenger operations used a Torque Converter to transmit power from the 2 diesels to the axles. They sound much like a bus, but then the same diesel model was used in many city buses.
jis
Permanent Way Inspector
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Administator
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The Siemens DLRTs used on the Oceanside - Escondido Line also use a torque converter.
Great explaination.Electric is always substantially cheaper to operate.
The cost of maintaining the system of overhead wires is large enough that the cost of operation + maintenance for electric may be higher than for electric for a line seeing only a few trains a day.
However, the big issue, as Mr. Harris says, is the cost of building the electrification system in the first place, which is very large. The cost savings from operations aren't usually large enough to cover the cost of building the electrification in the first place, except on lines with intensive service (different people have put the breakpoint for "intensive" service in different places; I've heard everything from 1 train/hour to 4 trains/hour).
(Remember that the cost of building the electrification has to be borne upfront, while the savings comes in over many years -- when you add in the cost of interest on the bonds issued to fund the electrification, then you start finding that the savings don't pay for it. If you have nothing better to do with a huge pile of cash, of course, electrification will always *eventually* pay for itself, but if the payback time is 100 years there would probably be something better to do with the cash.)
There is another nasty issue: it's a pain to have a partly-electrified line. Amtrak has a bunch of delays in its schedule from engine changes between electric and diesel, you'll note. So it turns out that the payback is a lot better from electrifying a whole system than from electrifying a few pieces of it.
BNSF did a study on electrification which has not been made public, but there were some leaks from it. The conclusions leaked were:
(A) it was not cost-effective to electrify part of the system; if they electrified, they should electrify *everything*;
(B) electrification was not cost-effective at then-current diesel prices, but would be if some (unspecified) higher diesel price were to persist. The higher price was never stated but was implied to be not that far above the then-current price. Of course, since then diesel prices have dipped for several years.
For reference, the advantages of electrification are many, and more than George Harris realizes.
(1) Small thermal power plants are far less efficient than large ones. Yes, it *is* more efficient to power an electric engine from an overhead line powered by a big diesel-powered power plant than to run a diesel locomotive, because the big power plant is more efficient than the one in the locomotive.
(2) Power line transmission losses are relatively small, contra Mr. Harris. They are practically irrelevant compared to the immense costs of transporting fuel such as diesel by truck, or even natural gas by pipelines. (Pipelines cost a fortune to maintain compared to power lines.) It is generally much more efficient to locate a thermal power plant next to the source of fuel (the mine or whatever) and move the electricity, than it is to locate the power plant next to the place where the energy is used and move the heavy, heavy fuel.
(3) Carrying the fuel and engine for a diesel locomotive is *dead weight*. Not carrying the power plant means you aren't moving that stuff around -- a great savings.
(4) Solar (with energy storage) has much, much larger potential than Mr. Harris thinks -- it's getting very cheap to install, it has minimal operations costs, and there's enough solar energy to power pretty much everything. Yes, storing energy at night is a big issue, but even if you could power everything with solar during the day (switching to gas at night, say), that would be a *huge* improvement.
Natural gas locomotives are a dead end. They'll work fine, of course. But then the price of natural gas will go up and they won't be a good choice. Fracking is only suppressing the price temporarily; there simply isn't that much gas to be gotten by fracking, as most fracked fields run out in 5-10 years. (Fracking for gas -- as opposed to liquids -- is actually unprofitable now and has been for quite a while. The current gas fracking companies have a business model based around land-flipping and violation of environmental standards.) Housing insulation and people switching their heating from gas to electricity will provide somewhat more sustainable downward pressures on the natural gas price, but the use of natural gas to provide peaking electricity generation will provide a countervailing upward pressure. It is also in demand for stoves and industrial uses which puts a floor on the demand.
Meanwhile the price of electricity is being held down by several things, all of which will continue. Housing insulation (the gains which can be made from this are on the order of 90%); the swap-out of incandescent lighting for LEDs (which use <1/10 as much energy), which is moving slowly but continuously; other efficiency improvements which are being driven by the desire to maximize battery life on gadgets; the continuous deployment of small-scale solar, which shows up in the electric utilities' reports as reduced demand; and large-scale solar, which now has a levelized cost cheaper than coal in some (sunny) regions. Counteracting that is the upward pressure from the deployment of electric cars, but that's going much slower than the downward price pressures. Other upward pressures are from more electronic gadgets (cancelled out by efficiency gains), from people switching heating *to* electric (but they usually make energy-efficient improvements to their house at the same time, cancelling that out), and from increase in number of households (which is slow and even stalling out).
There's some serious weirdness with electricity pricing in a few regions where the monopoly utility is charging far-above-market prices to pay for 40-year-old nuclear power plants and crazy stuff like that, but don't let that confuse you. (Though if you're running a railroad, be careful to locate your supply substations outside those regions.)
My analysis of the trajectory of energy prices says that the $$$ advantages of electric over fuel will get better and better for several decades at least. The potential bankruptcy of a number of utility companies complicates things -- better to have your own solar.
A couple of minor quibbles though.
Natural gas (methane) vs diesel has potential advantages to being cleaner burning, less nox and carbon particulates. With enviromental regulations considered natural gas may not be a dead end.
Electric automobiles are, imho, likely to be a "dead end" or at least a limited "niche" use. Without some incredible breakthrough in battery technology the limitiations of excessive battery dead weight, limits to recharging speed, and battery costs, including upstream and downstream enviromental costs, make them a non-contender. Too often the "business plan" for electric cars assumes the right for the vehicle to be charged for "free". Hybred vehicles will find use where there are a lot of starts and stops... switch engines one of them.
MikefromCrete
Engineer
The high cost of installing electric substations, overhead wires, third rails, etc., has just about always knocked out long-distance railroad electrification in the U.S. You need a very high volume of traffic to make it worthwhile.
N
Nathanael
Guest
Ah... but biodiesel!
I think automobiles in general are going to get relegated to niche use, so I'm not going to argue. Gasoline cars are certainly not going to remain viable for the masses.
N
Nathanael
Guest
FWIW that breakthrough has already happened (actually, there are several candidates for it) -- it's just a matter of commercialization and industrial-scale manufacturing. Which will take a while, obviously.
N
Nathanael
Guest
Yeah. But as I said there's an extra wrinkle.
Lines like the former New York Central mainline certainly have enough volume to justify electrification -- probably all the way from NY to Chicago.
But it makes no sense to electrify only one line. It's a pain in the neck to switch engines whenever a train needs to go to a branch line.
Ryan
Court Jester
Timely article: Around the clock solar electricity generation:
http://arstechnica.com/science/2014/02/making-solar-power-even-after-the-sun-goes-down/
Comes at the cost of significantly increased cost and lowered production during the main hours. Even then, it's only a few hours of extra production.
jis
Permanent Way Inspector
Staff member
Administator
Moderator
AU Supporting Member
Gathering Team Member
I think the study of the optimum mix of pre-production and post-production storage of energy in the form of heat vs. electricity is at its infancy at present. There is much to learn, and engineering is all about working out such details.
Ryan
Court Jester
I'm sure the first internal combustion engine didn't work all that well either. Good thing they didn't just write it off as "not as good as what we have now, forget it".
N
Nathanael
Guest
FWIW, energy usage is generally a lot higher during the day when the sun is shining *anyway*. Lots of stuff shuts down and closes at night.
Much of the nighttime usage is for two things:
(1) lighting, which is going to be a massively reduced electrical load as LEDs take over
(2) heating, which can be massively reduced by proper insulation
(There's also industrial stuff and whatnot, of course, but that's not dominant.)
Even if we just converted all the "daytime peak" electricity production to solar, it would be huge.
Much of the nighttime usage is for two things:
(1) lighting, which is going to be a massively reduced electrical load as LEDs take over
(2) heating, which can be massively reduced by proper insulation
(There's also industrial stuff and whatnot, of course, but that's not dominant.)
Even if we just converted all the "daytime peak" electricity production to solar, it would be huge.
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