Why don't we build power plants next to coal mines?

[rbroome]

@Una_Persson

Sorry, I forgot to answer the second part. Open-pit is part of it, and a labor force that gets paid much less than in the US is another part. However, you can get open-pit coal from Wyoming for as little as $4 a ton (and if you are willing to forgo some mine-site blending, slightly less than that). The largest factor of all is that ship transport of an easily loadable/unloadable item like coal is just very inexpensive, and the rail situation in the US is set up such that many coal plants are only served by a single company - thus, that company has a monopoly, and can charge whatever the market will bear.

To give an example of how much this monopoly adds to our delivered coal costs (and as a result your utility bills), consider this: I spoke once with the VP of a large utility, who told me that her plant, which had been served by only a single rail line, spent tens of millions of its own money to build a line connecting to a second company’s line, so they could see some competition in rail costs. Although there was a lot of anger and even outright threats from their original rail company (who threatened to cut off ALL coal shipments if the plant connected up to one of their competitors, to the point where the State had to threaten to sue the rail line if they shut down a plant supplying power to 2M people), when they were done the competition dropped the price of coal so much that their investment had a payback period of about 8 months.

Amazing. Thanks
The idea that a large American company like a railroad would try to act like a six-year kid holding his breath is just so sad. I am well aware of how prices are set (by what the market will bear not what the cost of production is), but to try to use blackmail to maintain a monopoly is, well sad. Glad they got stopped and hope they learned a lesson.

[Hari_Seldon]

I understand that the power transmission system in the US is a hodge-podge of locally owned systems, no one of which has much interest in upgrading. I have read suggestions that the US would be better off starting over with a unified grid. I am not sure there are more losses in sending power 1000 miles over a modern 730KV DC system than to send the coal 1000 miles. This becomes even more urgent when the possibility of solar power from the desert or wind farms (say, in the Senate) would require long distance transmission.

Here in Quebec the power company owns all the generation and transmission installation and most of the power is generated 1000 miles from where it is used and mostly now sent at 730KV and nowadays, often DC, which doesn’t have radiative losses. It used to be that high power rectification and inversion were expensive, but with new solid-state converters, this is no longer so.

[Walloon]

@Una_Persson

So the primary, #1 reason coal plants are sited away from the mines is T&D losses.

Translation of “T&D” for laypersons?

[MikeS]

@Walloon

Translation of “T&D” for laypersons?

“Transmission and distribution”, I believe.

[Una_Persson]

@MikeS

“Transmission and distribution”, I believe.

Exactly, thank you.

[GusNSpot]

@Hari_Seldon

I understand that the power transmission system in the US is a hodge-podge of locally owned systems, no one of which has much interest in upgrading. I have read suggestions that the US would be better off starting over with a unified grid. I am not sure there are more losses in sending power 1000 miles over a modern 730KV DC system than to send the coal 1000 miles. This becomes even more urgent when the possibility of solar power from the desert or wind farms (say, in the Senate) would require long distance transmission.

Here in Quebec the power company owns all the generation and transmission installation and most of the power is generated 1000 miles from where it is used and mostly now sent at 730KV and nowadays, often DC, which doesn’t have radiative losses. It used to be that high power rectification and inversion were expensive, but with new solid-state converters, this is no longer so.

DC current is now as good or better than AC for long distances?

I din no dat… How do day do dat? Require a two wire system and no earth ground? Splain me please…

[Chronos]

The advantage of high voltage is that you can crank down the current very low for any given amount of power delivered, and therefore minimize resistive losses.

The advantage of AC is that it’s easy to build transformers to change the voltage and current, so you can crank up the voltage (and down the current) for long-distance transmission, and then step it back down for the folks using it (who don’t have the safety equipment to handle hundreds thousands of volts in their homes). The disadvantage of AC is that you get an extra source of loss in transmission, radiative losses (effectively the wires act like a huge low-frequency radio antenna).

Nowadays, though, they’ve developed devices which do the same job as a transformer, but work on DC. So you can still take advantage of ultra-high-voltages for long-distance transmission, but without the radiative losses.

The presence of an earth ground is irrelevant. All electrical systems that I know of use at least two current carrying wires, and would function just fine (albeit perhaps not as safely) without a ground.

[Una_Persson]

Another advantage of HVDC is that it’s not synchronized, so it is resistant to failures where one part of the grid goes out of synch with another part.

The two-wire systems are on either side of ground (+/-), not at ground. There are earth-grounded systems but I do not know how common they are.
See also this: http://www.energy.siemens.com/cms/us/US_Products/Portfolio/HVSystemsupto800kV/HighVoltageDCTransmissionSystems/Pages/BasicsofHVDCTransmissions.aspx

There are also tripolar systems, but I can’t explain those very well.

[Chronos]

Another advantage of HVDC is that it’s not synchronized, so it is resistant to failures where one part of the grid goes out of synch with another part.

This is true. Even aside from failures, it’s not straightforward to define phase in a power grid of size comparable to 1/60 of a lightsecond (a few thousand miles), so if your grid is big enough, then you’ve always got something resembling being “out of synch”, even when everything’s running perfectly.

[BubbaDog]

I just stopped here to offer any help that can. I’ve worked in transmission planning and resource planning as well as power marketing. Una handled the majority of the questions. I just have a few points to add.

Other advantages of power plant location include local voltage support and support for transmission outage contingencies. During peak load conditions some power plants are “must run” not for their production but simply to hold up the voltage of the transmission grid in that part of the system. I know of plants in western Kansas that are dispatched under that rule. Granted plants aren’t built just for voltage support but that definitely keeps some of the older ones on the grid.

Una made a comment about the possibility of a problem crossing the grid boundary into Texas. The “problem” shows up more as an economic issue in that the congestion on the DC ties can get quite expensive during peak periods. A market group I was associated with made very good money by owning transmission rights on one tie and using that as an arbitrage position between two market areas.

One thing that seems to be less empathized in this discussion is that even though it may be more economical (in theory) to produce power at the mine and then transmit it out, that idea gets clobbered by the cost of new transmission construction to supplement or replace the existing systems which are already congested. Throw on top of that some NIMBY issues occurring with transmission right-of-way and and “why’s that stinky old power plant messing up my air and sending the power out of my state” and well, a good idea gets crushed.

[BubbaDog]

@HongKongFooey

One of the reasons, I think, is politicians in each jurisdiction need to get jobs for their area. One fights for a big project in one area and another fights for another part of the project in another area, neither cares about the overall project so much as making a name for themselves in their region.

I’ve never seen this happen for coal power plants. While some politicians may be receptive to power plants in their area most seem to be fighting to keep coal plants out of their states. One example is the Holcomb power plant proposed in Kansas. The story linked here displays the typical squabbling that goes on within a state’s government.

I would think that one factor (possibly small) about locating the plant within your own state is that other state’s won’t allow it on their turf.

[Public_Animal_No.9]

@BubbaDog

I’ve never seen this happen for coal power plants. While some politicians may be receptive to power plants in their area most seem to be fighting to keep coal plants out of their states. One example is the Holcomb power plant proposed in Kansas. The story linked here displays the typical squabbling that goes on within a state’s government.

I would think that one factor (possibly small) about locating the plant within your own state is that other state’s won’t allow it on their turf.

The ability to site a plant is a big factor in where they are located. These days, there are lots of people and groups that fight tooth and nail to prevent siting near where they live, where it might cause pollution - that is, pretty much anywhere. But there are quite a few plants located in the Rocky Mountains that send a significant amount of their power to California, given the impossibility of siting a coal-fired plant in that state. Some of those plants are sited because of proximity to coal, others because of proximity to water, and still others (particularly in Navajo Indian country) because the governmental authority was indeed looking for jobs. Most of that happened in the late 60s and early 70s, and has quieted down considerably since then.

Thanks, Una Persson, for the very nice discussion of the coal vs. electricity transport issue. Care to add your thoughts about adding a CO2 pipeline network to the coal transport/electricity transmission system? Nothing like a bit more complexity to make things really interesting.

[Chronos]

I’ve never seen this happen for coal power plants. While some politicians may be receptive to power plants in their area most seem to be fighting to keep coal plants out of their states.

Interesting… Montana politicians, from what I’ve seen, seem to love the idea of power plants in our state, mostly since any electricity that flows out of the state is dollars flowing in.

[BaneSidhe]

@Una_Persson

I work for a utility and government consulting firm, not in any government capacity (although I’m sometimes hired by State, the US, and governments of other countries).

Cool! I thought that might be what you did but wasn’t sure. Thanks for the answer.

[Una_Persson]

@Public_Animal_No.9

Thanks, Una Persson, for the very nice discussion of the coal vs. electricity transport issue. Care to add your thoughts about adding a CO2 pipeline network to the coal transport/electricity transmission system? Nothing like a bit more complexity to make things really interesting.

I’m a consultant on two projects looking at CO2 pipelines for carbon dioxide sequestration. What can I say…well, I love it, because the economics are so poor it makes my job easy. When you have a significant amount of CO2 to store, and most power plants are not located next to a tertiary oil recovery site…it’s just so expensive to transport it. And the logistics/siting problems, NIMBY stuff…it’s getting insane. Most folks don’t seem to object to a CO2 pipe, until the Sierra Club sends flyers to the town reminding them that CO2 is heavier than air, and in the event of a major pipeline break the gas will suffocate everyone nearby like Lake Freaking Nyos. Plus, as I mentioned in another thread, there is a bit of history with CO2 sequestration that’s starting to show some unexpected results, such as the reservoir caps being corroded by carbonic acid, and much, much more seepage and leakage from the reservoir than thought (including one case where part of the deep aquifer water was being carbonated like seltzer…not good.) For all people like to point to the North Sea and Canadian projects that have been storing CO2 pretty much successfully, those are small-scale operations compared to what we’d need to make a serious dent in our net GHG emissions.

(Never mind the fact that using CO2 for tertiary oil recovery means that you then extract more oil, which you burn…to produce more CO2).

[Public_Animal_No.9]

Thanks again, Una Persson. Are the results you discussed about corrosion and other problems published anywhere? I’ve got some interest in that very topic, and haven’t seen a lot of info on those sorts of issues.

[Una_Persson]

@Public_Animal_No.9

Thanks again, Una Persson. Are the results you discussed about corrosion and other problems published anywhere? I’ve got some interest in that very topic, and haven’t seen a lot of info on those sorts of issues.

You know, I honestly don’t know. I was out west talking to some R&D guys (pro-CO2 storage guys) a few weeks ago who were saying they were very concerned about it, to the point where they were looking into some sort of zirconium ceramic plug instead of concrete. But I confess I’ve never researched it personally.