Re: Hydrogen Economy Requires Cooperation



Don Lancaster wrote:

Mike McWilliams wrote:

Don Lancaster wrote:

Mike McWilliams wrote:

or take the time to review the efficiency of ICE vs. electric motor.




It has yet to be shown whether fuel cell/electric motor vehicles can even remotely begin to approach ICE efficiency. Certainly none of them do today.

See http://www.tinaja.com/glib/energfun.pdf



I of course opt for constantly grid connected systems like trolleys as opposed to vehicles with autonomous storage.

I am also curious as to why a 42 volt electric system is required for increased ICE efficiency. Is this to run on-demand electric devices that replace the pulley/belt system?

Basically, yes. And it will make it cost effective to do it with less copper.

Electrical losses are proportional to current.

No, incomplete. The loss is I^2 * R. Now you can use less copper.

The higher the voltage, the lower the current for a given wattage.

Also many solid state control devices will drop a volt or more in their on state. This is much higher of a loss fraction at 12 volts than at 42.

Actually, MOSFET drivers have an Rds of a few mOhms. At 5 mOhms you would have a .02v drop for a 50 watt headlamp. But you can save money with smaller devices.

Voltages above fifty or so raise shock hazards and have increased insulation and compliance costs.

Electrically controllable valves are one of many ICE efficiency improvers that will demand higher wattage electrical systems.

It also means you can electrify much more like the power steering, water pump, even the air conditioning. Less copper makes it economical. There is even talk of an SOFC plant for the system.

--
"We need an energy policy that encourages consumption"
George W. Bush.

"Conservation may be a sign of personal virtue, but it is not a sufficient basis for a sound, comprehensive energy policy."
Vice President *** Cheney

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