Jan Steinman said...
Ah, were it only so simple. It's tricky getting useful amount of power from salvaged alternators from most natural sources of rotational energy. They are designed for high speed, and it is unlikely that things designed for low-speed use (like bicycle chains and gears) would be useful or long-lived in a transmission. Making efficient gearboxes to get the necessary speed will take more effort and energy than simply making efficient, multi-pole low-speed alternators. This is why you don't see plans for such things in Mother Earth News or Home Power magazine -- it's really, really hard to get 5,000+ RPM from the wind!
That's not to say the entire premise is flawed, but having experimented a bit with them, I think the specific premise of using car alternators is unlikely to fly.
8/26/06, 10:27 PM
Tully said...
JMG,
I understand the broad-spectrum point you are making with this (having done what is currently called "remote lifestyle") and dabbled with "creative slavaging".
The way the RV refrigerators are designed there is a myriad of ways the could be adapted to work. The 12v DC application of them is actually quite power consuming and the least efficient option for runing one. THe most efficient method for using these is actually the natural gas system, using a flame no larger than a bic lighter. Designed originally to be propane-fed, with a minute adjustment of the pilot orifice and air-shutter it could be powered by methane. Methane generating systems are very simple to construct and can be fed raw material simply from barnyard animal droppings. We used to power our fridge on one BBQ propane cylinder for up to two weeks between refills.
As well, I've tinkered with the old-style (circa 1960's & earlier) automotive generators (not the newer alternators, they require electricity (energizing the field coils) to produce electricity. Another "salvaging" suggestion is the older style (non electric) automotive cooling fans to use for propeller blades, easily adaptable to mounting directly onto the generators, thereby causing less stress on its bearings than a heavier prop and cancelling the need for belts and pulleys which will detract from the applied kinetic energy.
Tully
(from the AODA list)
8/27/06, 1:02 PM
John Michael Greer said...
Jan,
Well, having been part of a team in the early '80s who built a quite functional wind turbine around a salvaged car alternator, I suspect it may be a bit easier than you think. The efficiency was low compared to generators designed for the purpose, sure, but we kept a 12v system trickle-charged enough to run a couple of light bulbs and a car stereo: modest, but in deindustrial times, better than no electricity at all.
More generally, one of the points of the post is that mechanical efficiency isn't the only factor that has to be considered in a deindustrializing world. In that setting an inefficient technology that's basically free, because essentially all its parts can be scavenged, can be more economical than an efficient technology that requires significant inputs of new resources. So even if alternator-based wind turbines aren't efficient, and their transmissions have to be replaced frequently (with more scrap parts), the fact that most of the parts will be available for free puts it within reach in situations where new tech won't be.
8/28/06, 11:11 AM
FrankG said...
Mr. Greer,
I've spent the better part of the last 2 years, investigating exactly what you outline (developing scrap recovery stratagies for reasonable energy projects)...
I believe that this is one of the few tangible activities that one can engage in to mitigate the overwhelming depression that typically follows internalizing the realities of "Peak-Oil"...
The link below is to numerous projects that I've posted specifically about home grown power...
http://www.theworkshop.ca/energy/energy.htm
In addition the following link (below) is to a comprehensive overview of how to establish a one-person metal foundry operation (a key skill to developing other technologies)...
http://www.theworkshop.ca/casting/casting.htm
FrankG
www.theworkshop.ca
8/29/06, 5:10 AM
John Michael Greer said...
Frank,
Thank you for posting this excellent news! The sooner people get working on the fundamentals of a salvage economy, the less traumatic the transitional period is likely to be. Good work.
8/31/06, 10:54 PM
