Skip to Content.
Sympa Menu

homestead - Re: [Homestead] Nuclear energy in an oil-poor world

homestead AT lists.ibiblio.org

Subject: Homestead mailing list

List archive

Chronological Thread  
  • From: "Wendy" <crazygardens AT verizon.net>
  • To: <homestead AT lists.ibiblio.org>
  • Subject: Re: [Homestead] Nuclear energy in an oil-poor world
  • Date: Thu, 02 Jun 2005 00:31:35 -0400



At 6/1/2005, you wrote:
I cannot see using solar as a stand-alone system. My planer has a five
horsepower motor. Batteries would never handle the starting load.

Do batteries start your car?

Very different loads and batteries. To start an AC load such as a
synchronous motor, you have to contend with huge inrush currents before
back EMF increases the load and reduces the current. The high starting
loads add to the power requirements. Inverters are sometimes designed to
handle those surge currents but they do drag the battery into low voltage.
Sometimes the inverter will see this low voltage and shut down.

Deep cycle and marine batteries are designed for steady current drain to
get maximum capacity. SLI (starting, lighting, ignition) batteries are
designed to generate large amounts of current quickly then just as quickly
recharge. The starter motor is a fractional horse power motor so has
smaller inrush currents, also as both field and stator coils are
energized, back EMF builds much more quickly.

Don Bowen Awl Knotted Up

You are absolutely right, Don. It is not a good comparison. What is
usually done with RE systems, is the AC motors are replaced with DC motors.
If you add a clutch and gear assembly that allows the motor to start
no-load, then the load is applied more gradually, would place even less
stress on the batteries. I wouldn't want to use an inverter anywhere except
where it was absolutely necessary. For the most part, they are an
unnecessary expense and a waste of power.

Wendy






Archive powered by MHonArc 2.6.24.

Top of Page