With 20 gpm you have over 400w theoretical, turbine should exceed 80% and a car alternator within its reasonable speed range may manage 60% so that should bring you into the 200W category as long as you can regulate the field efficiently to run the turbine at optimum speed. Even exciting with resistors and no technology you should manage over 150W.
With a decent pmg built to match the operating speed you could probably manage over 300W but it violates your simplicity requirement.
You really need to find the turbine speed, any form of belt drive will knock your power down if you need to speed increase.
Flux
What does "PMG" stand for?
The Pelton wheel is 5", I'm not sure how to do the math to figure out how fast it would turn with 20 gallons of water per minute and 100' of head(230 PSI?).
Thanks for your comments so far![ Parent ]
Permanent Magnet Generator. Well alternator to be precice as it makes Alternating Current.
TomW
"Education consists mainly of what we have unlearned."--Mark Twain[ Parent ]
So at 100 ft head velocity will be less than root (64 x 100) or 80ft/sec.
The pitch circumference of the wheel is 4 x 3.14 " just over 1ft.
Speed will be 80 rps approx max theoretical on no load. Probably run at half that so that gives 40 x 60 rps or 2400 rpm. Nicely within the range of a car alternator assuming you are using 12v.
Don't know how long bearings will last in such close proximity to water and continuous duty.
Flux[ Parent ]
I would be building a frame with a waterproof shield to keep the alternator dry and isolated from the turbine. I suppose that if I had to change the alternator out every few years, or replace the bearings, that is a expense I can deal with. But I can't deal with the price gouging going on these days on this type of equipment.
I'm going to pick up some good books on the subject so I can understand the engineering a bit better, but you have certainly given me hope, thanks!
I would also be interested to hear from anyone who may have done something like I am describing.[ Parent ]
From what I have learned here, my 100' of head plus my 20+ gallons of flow per minute should allow me to spin a alternator @2200 RPMs. My projected energy needs are 400 Amps per day, or 16.66 amps per hour, according to the chart I should be easily able to produce the needed power and more with the larger stock Delco alternators. And it looks like there will be room for more improvement.[ Parent ]
