# Residential Hydro Power Generation



## C-Dog (Dec 13, 2007)

I have been looking into different ways to reduce the dirty power I have been buying for the house. I have cut electricity usage significantly (we have dropped on average about 100 kWh per month arty-smiley-048: ) by changing out the lights and appliances with more efficient ones. I am now looking into generating my own power. Here are my options I see I have:

1. Solar: Good southern exposure with roof pitched at correct angle, but I need more $$$.

2. Wind: Not so good wind where I am (tall trees and in a river valley)

3. Hydro: There is a small stream that runs through my back yard that I could harness.

Hydro will be the least expensive and most reliable, however I probably have to get environmental permits. Does anyone have experience with a residential hydro system on the order of 500 W to 2 kW?

Thanks!

C


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## Hill William (Dec 13, 2007)

You would have to go thru the permitting process to alter the stream around here


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## Dark Knight (Dec 13, 2007)

C-Dog said:


> I have been looking into different ways to reduce the dirty power I have been buying for the house. I have cut electricity usage significantly (we have dropped on average about 100 kWh per month arty-smiley-048: ) by changing out the lights and appliances with more efficient ones. I am now looking into generating my own power. Here are my options I see I have:
> 1. Solar: Good southern exposure with roof pitched at correct angle, but I need more $$$.
> 
> 2. Wind: Not so good wind where I am (tall trees and in a river valley)
> ...


You are on the right track C-Dog. If you have not done that yet the next step in order is the water heater. Installing a solar water heater is the first big change to do if you are really into it.

About the main topic on your post my advice is solar. I had the chance to see a photovoltaic system and I am into it. As soon as I have my own house I plan to install one. It is expensive so think about that as an long time investment. If you need info I have some links.

With solar power, depending where you are, you can even offset your power bill. There is a program called Net Metering that allows you to put the excess power provided by your PVS back to the utility grid. The meter will spin or measure in a bidirectional way: the power you consumed from the grid and the power you provided to the grid. Depending of the agreement with your utility you can even get paid for the power you put into their system. Most utilities will give you a credit and others will bill you for the Net use of power: Power consumed - Power put back.

Wind is unreliable, and in order to generate hydro power a small stream is not enough. If you take a look most of the hydro plants have a huge drop. They are pretty tall. I know you do not want to provide power to a whole city but it is the same concept, only in a smaller scale.I think a small stream is not going to provide enough torque.

Go Solar.


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## mudpuppy (Dec 13, 2007)

My senior project in college was really cool. We had to investigate, design and install an off-grid power system for a remote cabin owned by a conservancy. We investigated the three options you've listed and ended up going with solar. We did visit a couple wind installations and one house where the owner had both solar panels and a small hydro generator.

Since you're in a valley, wind is pretty much out of the picture. Solar is the most commonly used form of renewable energy for residential installations, and in my opinion is fairly easy to install. Solar panels have come down a lot in price, but they are still pretty expensive.

The big advantage of hydro is that it is producing power 24/7, where wind and solar obviously aren't. The installation I saw was on a very small stream (about 3 feet wide and a foot or less deep), but it's not just about size--it's about head. How much of a drop does your stream make? I don't recall for sure because it was 7 years ago, but I think this guy had about 10 feet of head and was able to power a 300 W generator. I'm sure there's other engineers here that can do the calcs to figure out how much you can get out of your stream (I'm just an EE).

The 'dam' for this installation was just some concrete the guy had poured himself. He then ran a penstock (I think it was 2" black plastic pipe) down to the generator (at the lowest point on his property). Obviously the 2" pipe couldn't carry the entire stream flow, so his dam was always spilling. Pretty simple setup, actually. He did say he had to get a permit from the Michigan Department of Environmetnal Quality, but it didn't sound like it was that big a deal in his case. Although he wasn't creating any kind of real resevoir and the stream was way too small to support fish.

Now, 300 W may not sound like much, but remember that it's running 24/7 so he's getting 7.2 kWh/day, or more than 200 kWh/month (assuming the energy isn't wasted and instead goes into a battery system or to the grid through net metering). This isn't nearly enough to run a whole house, but an installation like this would be pretty cheap and I think it is the option which would give you the most bang for your buck.

Personally, I think the hydro option sounds like a lot of fun to try, and even if it doesn't work out you can always go with solar. No matter which option you go with, keep us posted!


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## C-Dog (Dec 14, 2007)

Thanks. I would love to do PV solar, but the cost is prohibitive right now. I have strongly considered solar HW, since that has about a 5 - 7 year pay back with the federal tax rebate now.

For my hydro, the stream drops about 10 to 15 ft while it runs through my property. It is 3 to 4 feet wide and varies in depth from .5 to 1 ft. I was thinking of just diverting a portion through a pipe and running that through a turbine/gernerator. I would not be installing a damn or anything like that.


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## Guest (Dec 14, 2007)

^^^ That's pretty interesting.

I was at a workshop this past week (discussing hazardous waste) but I have experience in a number of cross-over fields. One of the subjects of interest turned to discussing on-site generation of electricity with a few folks who were looking to harness energy from (in this case landfill gas production). The primary issue seems to be rectifying the cost of micro-scale generators with the cost savings potential from the generation. It seemed in most cases that larger companies that have attempted small-scale efforts have abandoned the concept because on a 'fleet-wide' basis it actually turned out to be a drain.

Now, as far as your concept - I am thinking about what sort of regulatory drivers might come into play. The biggest thing in my mind is flood control - are you going to be releasing too much water at some time or withholding to much to affect your neighbors upstream or downstream. There will probably be requirements for monitoring water quality as well. Honestly, I don't know enough about hydropower in streams because in FL you DO NOT have enough topographic relief to generate sufficient head to generate electricity.

Good luck with your continued efforts - please continue to update this thread.

Also, let me know if there is anything I can look into for you regulatory wise that might assist.

JR


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## C-Dog (Dec 14, 2007)

At first glance, I don't see flood control as a problem, since I am not reducing flow. I will just be diverting a "sall"amount. I could have a problem with the environmental permits (don't even know if they are required yet) since I will be redcing the flow of the stream for a short distance to run the water through my turbine. But I really don't see a problem here either because down stream the stream is covered by a parking lot and road before it enters the larger river. If they can force the thing to run a mile or so in concrete ducting, why can't I run 20% through pipes to my turbine?


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## mudpuppy (Dec 15, 2007)

Sounds like your location is a good candidate for a small hydro generator, C-Dog. I'm wondering, though, how is it possible to make water flow through the turbine without building a dam? If water is like electricity, wouldn't it take the path of least resistance, and just flow through the stream rather than through the pipe/turbine? Again, I'm an EE so maybe I'm missing or misunderstanding something.


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## C-Dog (Dec 17, 2007)

mudpuppy said:


> Sounds like your location is a good candidate for a small hydro generator, C-Dog. I'm wondering, though, how is it possible to make water flow through the turbine without building a dam? If water is like electricity, wouldn't it take the path of least resistance, and just flow through the stream rather than through the pipe/turbine? Again, I'm an EE so maybe I'm missing or misunderstanding something.


Good pnt. I still need to look into it (as well as a billion other things). If I have to build a dam, then I can say it is a no go :-(


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## Desert Engineer (Dec 17, 2007)

You shouldnt need that large of a dam, it just has to be large enough to impound the water to constantly supply your penstock. Where i work, we have a small hydroelectric plant fed from a 12" pipe that get its supply from a small dam that only has a few feet of depth behind it. The head is created in the long penstock, which in my case is a couple of miles and about 500' elevation drop.

Hope that helps...


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## LindaM (Dec 24, 2007)

C-Dog said:


> I have been looking into different ways to reduce the dirty power I have been buying for the house. I have cut electricity usage significantly (we have dropped on average about 100 kWh per month arty-smiley-048: ) by changing out the lights and appliances with more efficient ones. I am now looking into generating my own power. Here are my options I see I have:
> 1. Solar: Good southern exposure with roof pitched at correct angle, but I need more $$$.
> 
> 2. Wind: Not so good wind where I am (tall trees and in a river valley)
> ...


Did you look into Geothermal? I knew an engineer in CT (I think in Farmington or Wallingford area) that built a house with geothermal heating. This was done when the house was built, not a retro-fit though.


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## C-Dog (Dec 24, 2007)

LindaM said:


> Did you look into Geothermal? I knew an engineer in CT (I think in Farmington or Wallingford area) that built a house with geothermal heating. This was done when the house was built, not a retro-fit though.


I didn't look into it, but I would imagine all of the digging and wells would make the retrofit too expensive.


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## C-Dog (Jan 28, 2008)

Here is an update on my power generation plans.

Nix the small hydro. I had a "friend" (only have talked a handfull of times) came over who is an "energy engineer" for a couple of beers and free consulting. He used to manage a medium sized hydro plant and now does on site generation consultation and application engineering. Anyways, we went back to the stream and he said the best place to build the damn was pretty far upstream from my property and that the permiting and approvals would not be worth the hassle and it is not worth the risk to do it illeagally...

So anyways, it looks like we will be doing some solar hot water in the near future. I will keep you posted.


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## Wolverine (Feb 1, 2008)

I was pulling for you, but the outcome is not unexpected.

I got a call one day from a guy who wanted to interconnect with the utility, but was very secretive about WHAT he wanted to connect. After some cajoling using the few clues he gave me, I got him to admit that he planned to build a micro-pump-storage facility in the northern suburbs, self-contained. (For the uninitiated, that's a hydro-gen that runs during peak, selling the power, then pumps water back up to the reservoir at night off-peak when power is cheap). Without being too pessimistic (since I'm an agent for The Man), I tried to tell him good luck but that it wouldn't work and that he should be careful that some snake oil salesman wasn't selling him an unworkable concept. A few months later I followed up and he said yep, that was it. Sounded good - the scale just doesn't work. It can be done, but it has limited applications where it can be successful, and it ain't easy.

There are some old factories on the canal in Augusta. One got converted to condos and, almost as a hobby, the developer restored the old hydro gens to service (heavy cost, low return). When they opened the sluice gates, the canal dropped 3 feet in about 3 minutes. Then the gates filled up with trash. It takes a lot of water to run a gen (well, to run a 1920's vintage generator).

It was neat to read about the small 300 watter above. I've read a few positive stories like that from out West.

I keep telling myself "just because I've never heard of it being done, doesn't mean it can't be done", and I keep secretly hoping that someone will blow my cynicism away one day, but until then, my green skepticism remains strong. Segueway to a pro-nuke rant...


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## C-Dog (Feb 20, 2008)

With all of the rain and snow runoff in the last week, the stream was roaring over its banks! If it only flowed like that all the time...


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