Posted on 01/22/2007 7:39:10 AM PST by aculeus
Good reply from an expert in the field. Some 20 years ago I talked to an engineer about his EMSL(ElectroMagnetic Space Launch)concept : a 1/2 mile long cannon that shoots projectiles directly into LEO. He said his main hangup, besides funding to develop this cheap* STS as a shuttle alternate, was the power spike needed from the ultra-capacitors, equivalent to a 5 million person city he said.
Another concept was the quenched superconducting rings-cannon. In 300' to 500' you attained the necessary 5 mps injection velocity by turning off the attracting ring just above the sabot. But VESTED INTERESTS, ie, "rocket scientists" at NASA saw EMSL as a threat to their fat federal salaries, it was quietly interred after the USSR fell.
*cheap : one pound in LEO is (mv^2/2 + mgh) worth all of 4 KWH. At 10 cents/KWH that's cheaper than postage. What's the latest figure for getting that same pound to LEO on the shuttle? See now what I mean by VESTED INTERESTS...
Actually all cars have several flywheels. However the most important for propulsion is the one mounted between the crankshaft and the transmission.
I believe that the problems with most WWI aircraft were due to a spinning engine that was 40%+ of the total weight of the craft. If used in a car the flywheel for electrical storage could be mounted in such a way as to put the gyroscopic torque in a plane that would not effect the cars handling or to cancel it out with multiple wheels.
the flywheel at the back of the engine is to keep the engine from stalling at low revs. None of the flywheels (brake disks, etc.) in current autos contribute to the propulsion of the car from their rotary inertia.
As you said the WWI engines were significant enough to cause the gyroscope effect because they were rotary engines in that the crankshaft and pistons were fixed and the rest of the engine itself cylinders, crankcase and all rotated. Turn right - slow climb, turn left fast dive.
To store significant energy you'd need a pretty massive very rapidly rotating flywheel. Not something I'd like to sit near. The gyro effect is probably trivial in comparison to the rest of the problems that flywheel energy storage brings.
Cars have flywheels but their purpose is more to even out the power of multiple detonations and give a little torque with sudden engagement rather than to store energy.
The problem with flywheels is energy is 1/2 mv^2. You can increase energy storage by increasing mass but the real payoff is increasing velocity. With increased velocity you have real problems with friction and tensile strenght of common materials. The things have to be sealed in a vacuum and use space age bearings. If a bearing fails or a seal fails or if the tensile strength changes with age, you have a very dangerous device sitting very close to the occupants. People are scared of gasoline explosions, hydrogen leaks, battery arcing and the like but all of those problems are potential energy that needs a trigger to convert the energy to kinetic. With a flywheel, all of the energy is kinetic wrapped up in a hope and a prayer. I would not want one spun up and have a bearing go bad.
As Heinlein said decades ago: The World doesn't need more energy. The World needs a better bucket to carry it around in.
For electric vehicle charging stations, I've always envisioned the charging port to be safely tucked away under the vehicle and never touched by the driver.
You would pull into the charging position and a magnetic sensor on the floor of the charging station would locate the connector on the bottom of the vehicle, move into position, raise up to connect, charge the vehicle, then retract. The drive controls would be automatically disabled so the driver couldn't accidentally try to drive off until the charging connector had fully retracted.
The real issue, I think, is the electrical infrastructure to support fast charging. It is true that electrical outlets are everywhere, but a ten minute charge of a 50KWH battery would mean charging at a rate of 300KW. That is 150a at 220v, assuming some inefficiency in the charger. For a typical 'gas station', which has 10 refueling positions, that is a LOT of power to draw from the grid. The equivalent of about 35 homes. This is where the large-scale packs in the article might come into play -- big piles at the station that can be continuously charging from the grid all day and night and provide the surges of power needed to charge a bunch of vehicles all at once.
If we had storage like this, there would be a big stack at the filling station to even out the load charging cars and there would be absolutely gigantic stacks at the generating facilities to even out the load for the entire supplied region.
Yep. And I see that I stopped my sentence in mid-thought. The draw is worse than I wrote.
"The equivalent of about 35 homes."
Should be:
"The equivalent of about 35 homes instantaneous draw for each vehicle being charged -- so the total draw of each station would be like adding 350 homes to that neighborhood's grid."
BUMP!
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