Hello all, newb here. However I am not exactly an electronics newb(although I probably know just enough to get myself into trouble concerning whether I really know what I think I know ). That aside . . . I am looking for an idea of where I may want to start.
I have some questions concerning 'base' voltage output of any given alternator, for use in charging a 12v battery bank.
Would using a 48v alternator for charging a 12v system make good sense while using an efficient buck converter ? I know there is more than one aspect to this question so let me explain some of my ideas.
First off I am thinking that while a 48v HAWT/VAWT may need a higher RPM to 'cut-in' at it's intended voltage, that cut-in speed would be lower for a 12v system. I am nearly possitive this is a good thing, however I am expecting some trade off's here, and am not exactly sure what they might be.
Secondly, I have been thinking a lot about using an a/c, PWM controlled/double mosfet designed buck converter. Again, I am not an Electronics genius, but I have found a shcematic or two(thanks to Ed Lenz's link pages). Anyways, from what I think I know, this would be good for converting that extra voltage to amps. SO I guess what my question here is this: does this make sense ? Is there a better way of doing things here ? I know that batteries will 'clamp' the output down, but not sure how high you can go before it can damage the batteries. If reasonable to use, my idea of placement would be just before the DC rectifier, which its self would be in close proximity to the battery bank. Hopefully, this would reduce as much line loss as possible.
This whole idea I have had here started with a conversation I had with a neihbor here that has had plenty of hands on experience with pre-made systems(24v Mallards). These PMA's mounted on a 20' pole burned out within 3 months of use in our area. He now uses a well designed AirX system I believe, and it works good, but does not output as much power as the Mallards when they work. My neighbor is a very experienced electrician, but since these car alternators on what looks similar to a wrought iron frame do not have a furling system, I suspect they ran wild until they burned out. Personally, I would not be adverse to using these if I could find a way to keep them in good working order, as my neighbor says they can put out a good 500W a lot of the time in moderate winds.
The Wind in our area here seems to average at about 5-7mph, but we can get some really good gusts of up to 60+ mph. The cool thing about here(Eastern AZ at ~5700FT above Sea level), is that we get a lot of sun, but when it gets cloudy(like it often does mid-day this time of year), the wind starts blowing. We already have a PV system, a very good one at that, but when the sun goes away . . .
What I am hoping here is making a HAWT/VAWT that can output a decent amount of power in low winds, but be able to live though the high winds here when they do happen. My idea of 'decent' is somewhere between 50W-100W between 7-14mph winds(but of course I would not mind more!). On the dump load end, we are considering designing a controller that will dump into a hydrogen generator. Heating water, or dumping that energy to air through resistors just does not make much sense to us, but I can understand the need for it if nothing else is possible.
Wrapping things up, I hope that I have given enough information for you guys/gals to comment on. Yes, I know I do not have anything very specific here, but please go easy on me as I know several of you are very knowledgeable concerning these things(this would be why I am posting here ) Any comments are welcome of course.
For what it is worth, we are completely off grid, and since the power company wants 10's of thousands of dollars to supply us with power . . . We also have a 30Kw cummings powered diesel generator, but that right now is only used to pump water(until we get a good pumping mill working - for irrigation/consumption), and to power the 220v shop equipment that we have. Eventually we hope to have the hydrogen generator I spoke of above manufactured, and working, as well as a bladder for storage, and possibly even a means for putting that hydrogen to good use
OH! and hey. Anyone have any ideas on where one could find surplus/used forklift batteries ?!