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Small Generation 2

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tulum

Industrial
Jan 13, 2004
335
Hello,

I have the oppurtunity to purchase a piece of land that has a river "running through it". At one point in the land the river has a steep change in head of about 20-30ft. In the 1960's the local utilities actually purchased the land to set up a small generating station (the foundation was poured). Does anyone have any articles on performing feasibility studies for small hydro generation? Also what is the smallest capacity I need to make it viable to connect to the grid (realizing every state/province has different issues)? Any suggestion are appreciated.
 
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Talk to the utility about size as well as other interconnection issues. You don't just "connect" to the grid; many issues have to be considered. You might also consider there must have been some reason the utility didn't put the generator in themselves!
 
Hydro facilities such as what your talking about would likely require permits and such. Because we learned alot about environmental impacts, such facilities have not been built since the 60's. The only way you can put a generator around there is to not modify the flow of water (no dams, no alternate water flow). Your biggest challenge will be getting the appropriate permits.
 
Hi,

I have some documentation here indicating:
-basicaly you would require a minimum head of approx. 8 feet.
- minimum water volume flow of 2m²/sec.

regards,

Danny
 
Question to Buzz marked ///\\The only way you can put a generator around there is to not modify the flow of water (no dams, no alternate water flow).
///Please, how can there be no alternate water flow and no modification of the flow of water while the hydro-project is still realizable?\\\
 
Jbartos, Thats my point.

His biggest obstacle will be getting the permit. Environmental impact studies will take as much time as the design and construction and will be hard to get because of the reputation of hydro plants. Yes they are one of the most efficient but they are also the most damaging to the environement and this is why no new ones have been built in the US for decades.
 
I should add that since there is 'head' that it may be possible to do this without any further flooding upstream. However, there are still issues with fish passages and such.
 
How big of a "river" is this? While living in Rural new-york there were more than a few farms that used their streams running though their land for power generation.

If this is a 'medium' stream/crick with good-flow, I somehow doubt you are going to be attacked by zoning people. Though, it sounds like this is a full-on river??

I have even seen a slick wood-cutting operation that was water-powered. 6-Foot circular saw blades are scary, BTW...
 
Points you might consider:

In making your study watch for high versus low head hydro.
Low head are often un-attractive commercially because they tend to be more expensive, prone to storm damage and subject to trash accumulation problems.

I think you could have a technically viable solution as low as 5 kW.

I think induction generators - induction motor running about 3% about synchronous speed is a common solution. Very simple controls and would probably be ideal if you are permitted to connect.
 
Buzzp: "they are also the most damaging to the environement" is a very broad statement. Compared to what? Dirtburners? Really?

My understanding (as a foreign observer, yeah anuther dang furiner) on the reason no new projects are being done in US is more to do with politiks, something about not wanting hydro generation to be included as renewable generation because it makes all the others look so bad in comparison, &cetera. And this (recent) "stuff" about GHG emissions from the reservoirs is about as scientific as (unmentionable).


Pechez les vaches.
 
While head is one aspect the economic return is due to the energy and this is directly related to flow. You need to graph the flow through the year, the formula that relates flow/head to power is Generator Output [kW] = Flow [l\s] * Head [m] * 9.81 * Efficiency. Use a V notch weir to measue the flow, when you have a years readings convert to a flow duration curve ( ie histogram of flow and period, use this to size the turbine in rough terms, from there a good internet search should turn up approbriate turbines, cross flow, turgo are apropriate for low flows. Many small hydros are now been promoted in places like New Zealnad due to their low environmental impact, and are economic if there is no large dam structures.
 
regardless of everyones opinion on wether or not hydro electric systems are more or less benificial to the enviroment it still needs to be submitted to your local department of natural resources or whatever governing agency in your area handles such matters, these installations do alter the natural order of things and are usually very hard to get permits for, probably why the oringinal owner of the land abandoned it, if you procede without all the appropriate permits you could be facing very stiff penalties, people take fish and wildlife migration habits very seriously these days and I personnally believe it is well justified. Tarzan
 
P.S. to tulum, I am sure you probably are regretting this post at times since it does stir up a lot of contraversy, I believe if you could design a small system possibly using an induction type generator and divert a small amount of the water without disturbing the natural flow of things you have a much better chance of getting it past the authorities
but a larger unit consisting of dammed up water or diverting large amounts of water will be next to immpossible. Tarzan
 
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