Coal fueled power plants?
In the US, a very large portion of the electrical power comes from coal. In the short to medium term, there is no way to avoid the combustion of coal.
In the Powder River Basin in Wyoming, abour 500 million tons of the cheapest, cleanest coal in the nation is railed an average of 7-800 miles each year, to feed power plants throughout the midwest and beyond. That requires 100,000 railcars burning in excess of 500 million gallons of diesel fuel, and contributing vastly to greenhouse gases, over and above the burning of the coal itself.
So my question is, what are the physical. engineering factors concerned with the idea that, rather then building coal plants near cities like Chicago or Detroit, we build one or more HUGE plants in the PRB itself, and use high voltage power lines to move the electricity, instead of the coal?
Any ideas?
Thanks, KJ, you let us know when you’ve developed a solution that does not involve coal.
Does anyone have a link that might give some details on the relative power losses in the high voltage long distance power lines used in many countries? In terms of % per mile would be great. Given that we’ve already got a huge network of transmission lines moving power where it is needed, the additioanl losses from the PRB source (again, average <800 mile trip) would strike me as probably less than that 500 million gallons of fuel.
Electrical transmission is not 100% efficient, ie, there are significant line losses due to less than perfect conductivity. It actually costs less to freight the coal by train and use local water and limestone than the value of energy lost during transmission. You also need to consider the capital cost of using existing roads and railways to transport coal fuel versus building new high voltage transmission lines.
EDIT - You asked what the percentage loss is. The line loss from electrical resistance increases as the square of the current and therefore decreases as the square of the voltage. That also means that the greater the load, the greater the line loss. So the percentage is a function of distance, voltage, and current, and its not a straight line answer.
here’s a link that explains the line losses in more detail:
I agree that coal fired power plants should eventually be shut down as they produce more air, ground, and water pollution than any other type of electricity, and they release more radiation than a nuclear power plant for the same amount of power produced. But on the short term we need to make better use of our energy sources and look at alternative sources capable of producing local energy without transportation and line loss costs. Nuclear energy fits our requirements better than any other technology we currently have.
Coal plants should be shut down.
Ohm’s law.
Even the best Copper wires have a certain amount of resistance. Electricity traveling up and down the wires is partially turned into heat energy and lost. This is why transformers have to be linked along power lines to keep the electricity flowing.
I assume it was calculated that it would not be economically viable to simply build enormous power plants far away from cities. As things stand, only about 5% of the chemical energy in the coal is eventually turned into electrical energy. This is due to entropy, which states no tranformation of energy can be 100% efficient. The coal is turned into heat energy, the heat is turned into mechanical energy and this finally becomes electrical energy. The 5% efficiency of coal fired plants is offset by the tremendous amounts of coal available. Shipping the coal is viable only because petroleum is still relatively abundant, although internal combustion engines are under 30% efficient. I can only assume that if they were as efficient as power plants, large cities would be built around coal reserves, not rivers or oceans.
Things will change if and when superconductors are developed. The sorts available at present only operate efficiently at hundreds of degrees below zero. If they could be made to operate at ordinary temperatures, there would be no resistance in the wires and coal plants could be infinite distances from cities.
Truthfully, it is likely that the fuel consumed to move the coal outweighs the losses of long distribution lines. Also the train is moving energy much slower than the power lines can.
The true physical limiting factors are likely economic. Economic in the true sense, meaning the use of limited resources to meet possibly unlimited needs and wants. Utilities need rights of way and permission from overseeing organizations. Establishing new rights of way and installing the equipment comes at a large cost while the rail is already there operating. There is also more opportunity for failure in a larger distribution system and associated maintenance costs.
The people involved have to balance these factors with the available resources. Being human, they may be short sighted. Being in a society, they can’t just do whatever they want. What you get is a result of the aggregate of these factors; These great many variables.
One big factor in locating any power plant is the availability of water both for cooling and makeup to the steam system.
For those who object to the CO2 emissions, it is possible technically to strip the CO2 from the stack gases, compress them and inject them into the ground. To do this, plants need to be located where there are underground strata that will accept the CO2.
a top contributor is asking , why ? , i thought u guys answer only
I have no idea. It must have been the right way to do it when the first plants were built. But one way to reduce the oil requirements is to electrify the lines. Initial costs will be high but the long term benefits are great. The CO2 generation is a separate problem.
There is 250 megawatts of power at the Black Hills Corporation facilities around Gillette at the Wyodak and Neil Simpson plants. These are Mine-Mouth power plants. At the upper end of the PRB in Colstrip, MT is 740MW. These are just the plants in the PRB that I’m aware of due to my working for Black Hills at a gas turbine plant in Nevada. I’m sure there are more
I don’t know the exact data for transmission losses but on a monetary note it takes about $2.25 million per megawatt of output to build a 100MW plant in the PRB (Wygen III). It’s about $1.75 to $2 million per MW for a coal plant proposed for eastern Nevada. The proposed eastern Nevada coal power plant will have to include 200 miles of new transmission lines to Las Vegas at $2 million per mile (at last estimate). So far we are up to $6 Billion. In order to get electrical power out of the PRB of that magnitude to a location that could use it, larger than Billings, Cheyenne, Sheridan, and Rapid City would take a lot of money to distribute that kind of power to Denver and Minneapolis.
I understand the logic behind your statement but monetarily rail transport to the usage location is a cheaper alternative, currently, for the power plant owners and investors.