Slashdot Mirror
Power Plants On Rails for California
SoCalChris writes "According to this article on Wired.com, the Sierra Railroad is planning to use diesel train locomotives to produce power for California. Each of the 48 engines are expected to produce 2.1 megawatts of power for a thousand hours each year. Another key advantage to this plan is that since the "PowerTrains" are mobile, they can be taken to the areas that need power the most, so it doesn't have to be routed across the state through our power grid."
Yes, they were designed to produce electricity. Modern diesel locomotives do not couple the diesel engines directly to the drive wheels, but rather use them to turn generators. The electricity produced is then used to run electric motors that power the drive wheels.
It may seem inefficient, but you've got to remember how powerful a locomotive is. Starting a train moving from a dead stop is just not practical using a conventional clutch and transmission. The motor and generator combination provides the same ability to start from a dead stop smoothly and transform torque/speed ratios with fewer moving parts, and much less wear on parts.
And in fact, the motor and generator are not much worse efficiency-wise than the friction losses in the transmission would be. These things are designed for efficiency.
Of course, they don't natively produce power compatable with the power grid, but as the article says, that's easy (and also pretty efficient) to convert with interters.
These trains were built to produce electricity. In fact, all modern locomotives are. the engines are designed to do one thing and one thing only: generate electricity. there are electric motors that do the pushing.
My father was an engineer for Burlington Northern before Santa Fe merged with them, and i remember as a child, going to the engine plant, and actually being INSIDE an engine cylinder - they're massive!
When i asked my dad why they were so big, he said "they need to be, they run all the time and it takes a lot of electricity to pull a train." being a smart lad of 8, i asked "don't the engines push the wheels?" through a lengthy discussion that i repeated with him over the years to get more detail, i learned that the engines produce electricity and the wheels are driven by electric motors.
It turns out that this is more efficient, in money, fuel effeciency, and repair time (imagine replacing the drive train if it were not electrically driven). all you do is replace a motor, instead of a drive shaft and/or transmission. (simplified explanation, of course)
It makes perfect sense for them to do this. Resourcefullness demonstrated brilliantly!
Naikrovek