If you can divert, I would make a small catchment pond at the top and take a pipe to the lower level, then you could fit a low head turbine at the low level where it re-joins the stream. It sounds as though you could easily manage a 12" pipe and that should give a nice steady source of power.

You could bury the pipe to hide it. This should be much better than any wheel in an open channel.

If you self build a Banki turbine is probably the best choice, but a Turgo, Pelton or even a Francis or Kaplan would work if suitably chosen. The last two could use a draft tube and gain you a few more inches of head.

Some ideas to think about.

Example: if you have 10 feet head and 1 gallon/sec (60 gallon/minute) of water you may get around 60 to 70 Watts for a daily harvesting of 1.44 to 1.68 KW/hour of energy that is good for lighting and entertainment.

I am traveling but returning after OCT 16,

I can help you with the design of your system, so keep my address and send to me a message nando37-at-comcast-dot-net

Regards

The alternator, it is not that efficient cause it lose power thru the rotor coils. Still, this is acceptable as it is rugged and potent and in your case you may be able to waste a few watts here. Many hydro has been built with those.

The charge controler,tough, is not efficient and does'nt charge appropriately for a homebrew system. This controler will just reduce the load on the alternator when it's not charging. This would mean impeller overspeeding and explosion from centrifuge forces as the water speeds it up and up and up if there is no load.

Thus, you need a suitable controler so that the less you charge, the more you dump in a load. This is not the same as just switching the load on and off to charge and no charge as in windmills. This usually involve Pulse Width Modulation. This mean you switch the lenght of the Charge Time and DumpLoad times in a cyclic fashion quite high (usually around 10,000 times per sec).

You will need to find or hack a charger that sense battery voltage and vary charge time in consequence. You don't want to dump 50A in an almost full battery. The Off time must be diverted to the load in the circuit. Should be pretty easy to come up by some electronic wiz. I might design one in the near future as I will build a micro-hydro at my creek.

The other ways is to make a centrifugal vane so that water deliver get reduced as the speed get higher. So that you'll limit the speed of the impeller. This essentially is one of the biggest catches, but really worth it as hydro is full-time ON and quite powerfull. For mechanically inclinded, centrifuge van is not that hard to do. You just have to keep an eye on it.

Btw, marine deep discharge batteries are the winner as for availability and fit pretty well the need. More is better than less, especially if you have 50 amps comming your way all the time... Since you would have the capacity to keep them pretty well charged with a good hydro, you can take the peaks without hurting them if you have a few.

Think well about speed or charge/dump control before spending 200$ on an impeller. Prepackaged solutions are one venue, but homemade is so rewarding...

Well, good luck with the system.

http://www.motherearthnews.com/printable/1985_January_February/Mother_s_Microhydroelectric_Plant_Rev isited