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  #1  
Old 12-18-2009, 01:54 PM
twhitt twhitt is offline
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Could I build a personal hydroelectric power generator?

Assume that my goal is to power my home year-round with minimal environmental impact. Suppose that I live in an area with hills and fast-flowing streams and am situated on plenty of land. I've decided that both windmills and solar panels are insufficient because they are unreliable. Could I build a small hydroelectric power plant that would be enough for my home and nothing more? Would it be a dam, or might it be easier to build a waterwheel or something else entirely? I would suppose it matters whether winter does or doesn't bring freezing temperatures, so to keep possibilities open let's assume that we're in a moderately warm climate where streams and lakes are unlikely to ever freeze over. I'm also interested in how much such a system would cost, and if it's even possible to get a permit for something like that in anywhere in the US.
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  #2  
Old 12-18-2009, 02:04 PM
Hello Again Hello Again is offline
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I saw a program about a guy (I thiink in Colorado?) who had a home hydro set up. I recall it was not necessary for him to dam his stream, he diverted part of it with narrowing channels to increase the pressure/speed of the flow, and part of it remained natural.

Similar to the section on diversion in this.
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Old 12-18-2009, 02:10 PM
Machine Elf Machine Elf is online now
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this book gives you all the practical information you need to know to make your own small-scale hydroelectric installation. This is intended for people who are trying to bring electricity to third-world villages in mountainous areas while utilizing, for the most part, locally available resources.

As for the legalities of an installation like this in the US, my WAG is that you will have all kinds of legal issues to overcome, such as water rights, environmental impact, construction permits, and so on. I'm curious to hear from someone more familiar with those issues.
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Old 12-18-2009, 03:15 PM
TroutMan TroutMan is offline
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All a dam will do is regulate the flow. Unless your stream is spring-fed (and even possibly if it is), it's probably somewhat seasonal. If the flow is always enough to turn your turbine, no need for a dam.
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Old 12-18-2009, 05:29 PM
engineer_comp_geek engineer_comp_geek is online now
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When I went to college, every first year engineering student had to design exactly this. We were given a pile of catalogs and had to make it out of real world parts. Unfortunately we didn't get to order the parts and see if our designs actually worked but at least conceptually it really wasn't that hard to do, from a technical standpoint. The cost range was a few thousand bucks for something that would power lights and a few things for a small cabin. Obviously, as your power requirements get larger, so does the cost.

Twenty or thirty years ago this wouldn't have been a problem, but it is my understanding that they've really clamped down on this sort of thing in more recent years. Depending on where you live, you may have to do some sort of environmental impact study before you can dam or even partially block a stream even if it is on your own property.
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Old 12-18-2009, 06:51 PM
Xema Xema is offline
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This is a tolerably common and not terribly far from mainstream way to obtain electrical power in remote areas. Google "mini hydro", "micro hydro" and "low head hydro" for tons of links.

But you're going to find that it takes an unusual situation for this to make good economic sense. The cost of a setup sufficient to reliably supply a single house will be substantial - very hard to justify if grid power is at all feasible. And, as others have indicated, mucking with the natural flow of streams is typically frowned on and subject to considerable control and regulation.
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Old 12-18-2009, 09:24 PM
NinetyWt NinetyWt is offline
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Quote:
Originally Posted by Joe Frickin Friday View Post
I'm curious to hear from someone more familiar with those issues.
A few things come to mind. Let me go ahead and say these may or may not be required in every state:

Building a dam requires a state permit for 'withdrawing waters of the state'.

A person may have to check for impacts to wetlands, and may have to get a Corps of Engineers wetland permit (404 permit) or permit to disturb X linear feet of a stream ('waters of the U.S.').

Construction nowadays requires a written stormwater pollution prevention plan be filed with the state. This includes a drawing showing where erosion controls are to be placed.

If the stream happens to be associated with a floodway as shown on the National Flood Insurance Program's mapping, then a Letter of Map Revision request must be prepared and submitted to FEMA for their approval before construction can begin.

These things are all certainly do-able, people do this kind of thing every day.
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  #8  
Old 12-19-2009, 02:24 PM
Napier Napier is offline
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A trout-man may have his reasons to dislike dams, but they do more for hydroelectric power than regulate flow. By damming, you get to raise the water height differential, and roughly speaking the power you can get from a stream is proportional to the height differential you can use.

There's a little hydroelectric plant not far from here, and it has about a 30" pipe above ground following a stream from its dam for a few hundred feet. Then there is a shack with what looks approximately like a 200 hp electric pump, but it is in fact a turbine and generator.

It makes life much easier if you get to connect to the power grid all the time. In this case your generator can be an ordinary induction motor, which will feet power back into the grid if you try to turn it faster than its synchronous speed (1800 or 3600 or whatever rpm).
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Old 12-19-2009, 03:09 PM
Sage Rat Sage Rat is offline
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I'm not the OP, but I'd wonder about how well one can do without damming the stream. (A paddle-wheel, for example.)

About how much power can you get from a stream say...two feet deep and 8 feet wide, forming a rough cross-section of a circle along it's bottom, and traveling at 2 feet per second?
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Old 12-19-2009, 07:18 PM
Machine Elf Machine Elf is online now
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Originally Posted by Sage Rat View Post
About how much power can you get from a stream say...two feet deep and 8 feet wide, forming a rough cross-section of a circle along it's bottom, and traveling at 2 feet per second?
Depends how much of a drop you put that water through.

One purpose of a dam is to smooth out seasonal variations in flow, for the benefit of residents in the downstream floodplain. Where hydroelectric is concerned, the other purpose of a dam is to pile up water to a significant height so that you can use it to generate a useful amount of power.

The book I linked to (see upthread) talks about building a pipe to take in water high up on the hillside and bring it down to the powerhouse. In this case, a dam isn't necessary. The power available from the flow through that pipe is a function of volumetric flow rate AND the height difference from the inlet of the pipe down to the powerhouse. After that, it's down to how effiently you extract the power. A Pelton wheel turning at its target RPM can have efficiencies of over 90%.
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Old 12-19-2009, 07:31 PM
Bijou Drains Bijou Drains is offline
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This federal agency probably needs to inspect and permit your dam/power plant. The big power company dam licenses run for 50 years, not sure if that is also true for private ones.

http://www.ferc.gov/
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  #12  
Old 12-20-2009, 02:01 AM
T. Slothrop T. Slothrop is offline
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At one time I was building a lathe and was pondering different methods of powering it. My brother who at the time lived in Newfoundland inquired about whether I paid for water where I live. Where he lived water was free and un-metered. He could have powered a lathe by turning on the outside tap.

I finally used the traditonal method, a washing machine motor.
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  #13  
Old 12-20-2009, 03:23 AM
Amblydoper Amblydoper is offline
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Originally Posted by Xema View Post
... mucking with the natural flow of streams is typically frowned on and subject to considerable control and regulation.
I am familiar with the water rights in Colorado. If water flows across your property, you may divert it, but you can not stop the flow. For example, you can add twists and bends to the water's path, but you can not build a lake or pond. Constructing a dam for a mini-hydro plant would be a violation of the water laws.
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  #14  
Old 12-20-2009, 03:58 AM
Shamozzle Shamozzle is offline
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There's a fellow near Horsefly, BC who has his own mini-hydro project on a small river. He generates more than enough for himself as he sells the remainder back to the power company.
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