microhydro
 

No specifc spot for hydro, so put here:

Have stream at cabin, about 1 cuft/sec in winter, only trickle in summer, so only winter usage.

Have not tried micro hydro as had not come across the few hundred feet of 4" schedule 40 or 80 pvc pipe needed until last year. Probably only a 40 ft head at most, but after a 300 ft horizontal run.

16 YO grandson interested in installing a micro hydro.

Anyone here done such?

I'll probably use a PM generator and feed 100 to 200 Vdc to cabin (almost 1000 ft away) and then thru custom inverter (can design/build one of those myself)

Went to powerspout and put in your numbers. Not a lot of power (19 watts)!

AdvancedCalculatorPage

Might be fun to try.

Steve

Steve, I think you might have tripped up on your inputs. Assuming the 1 cuft/sec wasn't a typo, that is about 450gpm. Using 40ft of head, 300ft of pipe length of 4 inch pipe I came up with about 680 watts. In fact the calculator notes that 4 inch pipe isn't enough at that flow rate, and the wattage goes up to about 1500 or so at 6 inches.

Great catch - you are exactly correct. My mistake on not looking at units.

Thanks


Steve

Mejunkhound, I think you should go for it, with some caveats. I would do the transport in AC. Otherwise you will need something like 4-6-awg cable at 200vdc to keep losses reasonable, all the way to 000 awg at 100vdc. I assume you're not interested in forking out that kind of coin for a pet project. Perhaps a small generator shed with the inverter right there?

Check out the link below for DC cable wire size.

DC Cable Sizing Tool - Wire Size Calculator - MM2 & AWG - solar-wind.co.uk

It's not AC/DC that matters for losses over long distance, it's the voltage. I actually recommend around 370V DC, which works with common universal input switching power supplies.

I finally hauled the pipe down to the cabin, have 120 ft of 4" down there now, will go down on spring break with grandsons and see how we can lay the pipe.
Creek was flowing above 1.5 cu ft/sec just judging by wier formula and flow depth over an edge. The previous week had some heavy rain, so the 1.5 cuft/sec probably about the maximum.
120 ft of pipe at 500 GPM has a 15 ft heat loss, so may want to lay 2 pipes in the future.

We will lay the pipe and see what type flow we get and what the static pressure is, will likely neck down to 2" or 3" as have that size valves.

After getting the actual flow and head measured, will design and weld up a turbine and install later this spring. If we get 200 W into late spring will be happy, enough to charge battery and run screens and laptops and a few LEDs. I plan on letting generator (rewound auto generator with rotor replaced with PM) run free, wild frequency and voltage, design a boost converter for 500Vdc output and feed that up the hill to a 120 Vac output inverter. I design motor drives for airplanes, so boost supply will be custom, probably rewire/adapt a commercial 480 Vinput VFD as the 120 Vac inverter.

The turbine will be the most difficult, unless a 1 HP mixed flow centrifugal pump I have can be adapted.