Tom
I also live off grid (20years) and generate power
with solar and hydro. My hydro site sounds somewhat
similar to your proposed site except that my house is
near the turbine and my intake is just a small dam
that holds a couple hundred gal. of water. A pond
makes a great intake so your maintenance on that end
should be minimal, but changing Nozzels can be a
hassle especially since your turbine will be some
distance from the house. From what you have described
about your site I think you must make some care full
measurements of available flow during the non-summer
months. Sounds like you should be counting mostly on
solar for summer. If you get a dry spell the the fall
(a month with little rain) How many gallons/min can
you count on? If you do not know the answer to this
question then perhaps alittle more study should be
done before you start sending money. If you could
count on 20 gallons /min or more your site would
produce at least 300 watts which should easily make
the effort worth while for an off grid battery system.
Such a flow could be accomadated with a 2 inch pipe
which is very economical. In my opinion its not worth
changing nozzels more than a few times a year. Forget
about the peak flows in the spring. Put a nozzel on
that you can be sure is going to be supplied with
sufficient water for the 8 or 9 good months and then
change to a small summer nozzel. During the summer my
site produces power intermittently. often it will
produce power(150 watts) during the night and
morning,but not in the afternoon and evening. those
deciduous trees are very thirsty on a hot sunny day!
The four inch pipe that you were talking about seemed
very large to me for a site with intermittent flow
three months of the year. This is about all I can say
with the limited information provided but would be
happy to comment further if you would like.
Peter Allen West Chazy NY.
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>
> There are 6 messages in this issue.
>
> Topics in this digest:
>
> 1. Re: ABOUT MICRO HYDRO
> From: Manfred Mornhinweg
> <[EMAIL PROTECTED]>
> 2. Re: Planning a new hydro system
> From: Eilrem Fernandez
> <[EMAIL PROTECTED]>
> 3. Effective water flow calculation
> From: "Mihai Radulescu"
> <[EMAIL PROTECTED]>
> 4. Fwd: Re: ABOUT MICRO HYDRO
> From: himani goyal
> <[EMAIL PROTECTED]>
> 5. Re: Effective water flow calculation
> From: "Radu Babau"
> <[EMAIL PROTECTED]>
> 6. Re: Effective water flow calculation
> From: Eilrem Fernandez
> <[EMAIL PROTECTED]>
>
>
>
________________________________________________________________________
>
________________________________________________________________________
>
> Message: 1
> Date: Tue, 30 Aug 2005 00:39:26 +0000
> From: Manfred Mornhinweg <[EMAIL PROTECTED]>
> Subject: Re: ABOUT MICRO HYDRO
>
> Hi,
>
> > HI Any body can tell me how i can determined any
> micro hydro plant
> > capacity if i know his Discharge,water head.
>
> Very simple: Every kilogram of water is attracted by
> Mother Earth with a
> force of 9.8 Newton. Force times distance traveled
> gives energy. So, one
> liter of water falling one meter gives 9.8 Joule of
> energy. If this
> happens every second, you have a continous gross
> power of 9.8 Watt. Then
> you must subtract the losses of the whole system
> (penstock, turbine,
> transmission, generator) to reach the final
> electrical power output.
>
> > If any formula please tell me in brief.
>
> Electrical power (Watts) = 9.8 * flow (liters per
> second) * head
> (meters) * efficiency
>
> The efficiency should be between 0.3 and 0.8,
> depending on the quality
> of the system.
>
> An example can make things simpler: Suppose you have
> a stream giving 30
> liters per second, with a usable head of 25 meters,
> and a system
> efficiency of 50%, or 0.5. You will get:
>
> 9.8 * 30 l/s * 25 m * 0.5 = 3675 Watt.
>
> Clear?
>
> Best regards,
> Manfred.
>
>
> P.S.: This is my first post to this group. I hope to
> buy a piece of land
> soon, build my definitive home on it, and power it
> from a microhydro
> setup. So I joined here a few months ago, to get
> into gear!
>
> --------------------------
> Visit my hobby homepage!
> http://ludens.cl
> --------------------------
>
>
>
>
>
>
________________________________________________________________________
>
________________________________________________________________________
>
> Message: 2
> Date: Tue, 30 Aug 2005 02:54:39 -0700 (PDT)
> From: Eilrem Fernandez
> <[EMAIL PROTECTED]>
> Subject: Re: Planning a new hydro system
>
> Hi Tom,
>
> I'm assuming that you're using GI or BI pipes since
> the maximum pressure at the bottom is about 85psi.
> Your penstock could handle up to 12L/s flow rate
> with reasonable efficiency.
>
> For proper operation, the intake only requires a
> minimum depth of submergence 3x its diameter,
> theoretically 12" in your case, which makes your
> plan (4ft) more than sufficient. However, if you
> could immerse your intake deeper, you can use the
> pond as water storage during the dry weather.
>
> You can operate the system at full power (around 5kW
> @12L/s for pelton runners, or 3-4kW for crossflow
> runners) when water availability is sufficient. If
> the system is outfitted with multiple nozzles or
> with a spear valve, you can just adjust the flow
> rate to match what is available.
>
> However, generators and alternators are notoriously
> inefficient when operating at partial capacity. So
> if you have sufficient water storage capacity in
> your pond, you can operate your system for a few
> hours then wait for the pond to fill up before using
> it again.
>
> May I know your battery bank capacity and the total
> watt-peak capacity of the PV array? Are you planning
> to use your microhydro just for battery charging or
> have plans for other applications? Are you using
> your system as a hybrid system? Are you planning to
> fabricate your own turbine? Such info is also
> relevant in deciding what is best for your
> microhydro system.
>
> Eilrem
>
> thomas_a_phillips <[EMAIL PROTECTED]> wrote:
> To introduce myself, our OTG Solar home is located
> on the Cumberland
> Plateau, north of Chattanooga. We use Solar
> electric, propane and
> diesel with some wood for energy needs. Our home
> sits on a bluff
> that rises 150' above a raveen with a creek. We have
> a 1 acre pond
> up on the bluff that is fed by a wet weather stream
> that runs 8 or
> nine (winter)months. The out flow from the pond goes
> over the bluff
> to the creek below.
>
> I have surveyed a route for a 4" penstock from the
> spillway over to
> the bluff and down the slope to a suitable turbine
> location. Total
> length of the penstock will be around 800 ft. The
> Penstock will be
> buried from the pond to the edge of the bluff. The
> slope is too
> rocky to bury it from there to the turbine site, the
> last 200'.
> Difficulties will be the length of the penstock, the
> fact that it
> traverses a dip before droping over the bluff, the
> need for concrete
> thrust and slider blocks on the steep slope, and the
> distance of the
> turbine from the house, probably about 600'.
>
> I have two questions I'd like some input on. One, I
> think I can
> place the intake for the penstock out in about 4
> feet of water in
> the pond away from the spill way. Is that a good
> plan?
>
> And two, It is a wet weather stream that drains
> about 50 acres. This
> year has been unusualy wet, so the stream has almost
> not stopped
> running. But other years we have seen little or no
> flow in July,
> August and September. (Of course the solar panels
> crank then). How
> are these periods of intermittant flow handled? Does
> it require
> constant adjustment, or do you just shut it down
> till you have
> sufficient flow?
>
>
=== message truncated ===
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