Generators and Hydropower

So the previous post produced a lot of knowledge about generators, which has clearly been of interest to many of you. I'm going to put a follow-up question out there: how much do you know about generating electricity with water?

I live on a mountain, with a clear and fast-running creek a few yards from my house. There's a good grade -- mountainside and all -- and the water flow is year-round. I've always thought that putting a turbine in the creek would generate enough power to run my house, and the source would be only a few yards away.

How much do you folks know about that project? 

8 comments:

Douglas2 said...

I've certainly looked into it but without direct experience. The turbines to "drop in" to a river or creek are playthings in my view, what's needed is a pipe picking up water uphill with sufficient head to go through a turbine near the downhill point. There's a pretty old "Backwoods Home" article that speaks of the survey, planning, and installation of such a system:
https://www.backwoodshome.com/a-small-creek-provides-plenty-of-power-for-this-off-grid-home/

I think also I would be heavily battling temptation to do it "on the sly" with minimal visibility to the casual observer, because permitting doesn't look fun.

Texan99 said...

Amazon has dozens of micro-generators suitable for water flow in a creek, from super-cheap little 12V camping models under $20 to house-sized models in the $3K range. Most are a few hundred dollars and big enough to help with a house. I see one for about $200 that generates 600W at 110V. Whole-house gas-powered generators tend to be more like 6KW to 16KW, but on the upper end that runs a full-sized house with AC in the summer without straining.

Unfortunately we have no experience with them, and although Amazon reviews are often helpful, there are practically none for this class of product.

Review article: https://www.popsci.com/gear/best-hydroelectric-generators/

Texan99 said...

"Permitting"? Yikes. Not here, thank goodness.

Anonymous said...

I don't think a run-of-river generator would require a permit, since you are not 1) disturbing the flow or 2)interfering with usufructary rights up or downstream. Diverting water, yes, because it would do both 1 and 2.

That typed, I am in a prior-appropriation area, where water laws are ... a bit more complicated as far as in-stream use is concerned.

LittleRed1

douglas said...

It's simple enough that I've seen them make water wheel generators out of found scrap (mostly) on the homestead rescue show.
Seems like a great idea if you have the conditions.

Anonymous said...

Hydropower is almost always the cheapest and most reliable renewable power system. The bad news is, a "run of river" system is not likely to be efficient enough to be useful. (Most of the water just bypasses the turbine.) You need to impound the water at a high point, then channel the flow through your turbine (at the low end of the race), then discharge back into the streambed. Potential power is then simply a factor of the flow rate and head:

Power (watts) = Head (m) x Flow (litres/sec) x 9.81 (gravitational constant ‘g’)

Most small water dynamos are about 70% efficient, so you'd multiply that potential power by 0.7 to get your expected electrical output. You also need various conditioning equipment, and if you are still grid-tied, there would be additional safety equipment (mainly to protect linemen from your system). Even so, microhydro is one of the few renewable systems that can often be justified on a cost-basis (i.e. without subsidy).

Two links from DOE:
https://www.energy.gov/energysaver/microhydropower-systems
https://www.energy.gov/energysaver/planning-microhydropower-system

--Janet

raven said...

IIRC, at one time, the Fed Gov had subsidies for micro power. John McPhee wrote about this,
in "Table of Contents", chapter "minihydro".

The ranger station in one of our Olympic parks has a nice pelton wheel set up, supplied by a 6" line from a creek- has a lot of drop, they pick the water up way up the hill, which are are close to vertical there. No longer in use, it sits moldering well off the path.

We also have a nice creek, with a waterfall about 12' high,but getting permitted for such an effort around here would require a social status I do not have.

With a small water flow or drop, perhaps a battery bank could be used to store the power for higher loads- this might make a minimal charge rate workable. Certainly it would be more reliable and higher output than solar or wind.

There are some very good YT videos out there on this subject.

Grim said...

Janet,

I've been trying to engage the local power company in the discussion, so far without success. I understand that they may be legally obligated to purchase power from me if we over-generate our needs, so that may be partly why they aren't encouraged in the discussion. On the other hand, protecting their linemen is a real concern. Those guys are good people who work hard; I would certainly not wish to endanger them.