Hydro on spring?

[Jedon]

I'll be moving off the grid soon and will have a pretty large solar setup so will have panels, batteries, inverters, charge controllers etc already.  Pretty close by ( 300 feet ) there is a year round spring that flows about 10gpm ( I need to more accurately measure it, could be a little more ). Considering the high price of solar panels, would supplementing the setup with power from the spring be a wise idea? I don't have a good notion of how solar vs hydro power compares, the panels are probably going to be Kyocera KC190GT 190W with max 7.28A at 26.1V each, I've been told I need anywhere from 12 to 24 of those panels and was kind of hoping that pulling some power from the spring would reduce the number of panels needed and provide some 24 hour power during the night and winter.

I read here that ((net feet of head) * (flow in GPM)) / 10 = watts

10gpm at 100feet = 1000 / 10 = 100W?

Thank you for any and all help!

-Jedon

http://darklingcastle.com

[drdongle]

A Pelton or Turgo wheel will fit the bill for that spring.

[Ungrounded Lightning Rod]

I read here that ((net feet of head) * (flow in GPM)) / 10 = watts

Other sources use that rule of thumb, too.

100 watts 24/7 is nothing to sneeze at:  It's 2.4 kwhr/day, almost what my vacation home averages.    Wish I had one of those things at my site.  B-)  (Of course the house spends most of its time running "scare the bird lights" and "keep from freezing the pipes" furnace operation, and would burn quite a bit more if it were continuously occupied.)

What matters for batteries isn't watts so much as charging amps times battery voltage at discharge.  Your 100 watts will get you 100/27 * 24 = ~89 amphours/day in a 24v system.  With your panels getting something like 5 solar hours/day (assuming clear weather) they're giving you about 36.4 amphours/day, so your spring replaces about 2.4 panels, or 10-20% of the recommended generating capacity.  (Of course the insensitivity to weather makes it more valuable than just adding a couple more panels, since it will generate when they're flaking out due to weather.)

Of course of it's more than 10 GPM it's more power.

I'd put in a genny with a source like that.

[Nando]

Jedon;

10 gpm = 0.63 l/s ; 100 feet = 30.48 meters

watts = 0.63 * 30.48 * 9.81 = 188 watts multiplied by the efficiency for about 100 watts or 2.4 KWH/day

The cheapest way is probably using a Turgo from www.h-hdro.com, using the blue color Turgo attached to a brushless motor, like 1/2 HP GE ECM MOTOR, I have designed a casing for such arrangement if you decide to go this way.

Try to use the larger diameter possible to reduce your friction losses.

Also the motor can generate high voltage which you can bring down with transformers to reduce the transportation losses, or possibly to rewire the motor.

Solar Panels should be analyzed well and not, I have been told, 12 panels * 190 watts * 5 hours a day is around 7.8 KWH/day generation

Investigate the water source well, measure the volume accurately as well as the head, even if you need to go higher or lower to find more head, remember more head first, then more volume.

If yuo can attain a head (meter( * water (liter) = 63 You can have better power than 12 solar panels.

Nando

[Jedon]

Thank you all for the info! This seems like it could be a good idea to procees with. I'll more accurately measure the head and flow this weekend.

My wife brought up a good point about temperature, when it freezes how do you protect the system? Bypass the pipes altogether if it is at all a risk?

I also have a larger but further away ( 1100ft) source of water that has less head but a whole lot more volume and it has the disadvantage of county regulation so if they know about it they might get their panties in a bunch.

[Jedon]

A local company offers Harris turbines, would this be a reasonable setup?

http://www.sierrasolar.com/manufacturers.php?manufacturer_id=74

[Nando]

Jedon:

You could make the turbine casing and buy the Turgo and the generator with the Nozzles for around 500 dollars ( even less).

Since the load is 300 feet away from the generator, you will need high voltage generation.

Three transformers with taps good for 240 watts and charge the battery bank.

I can assist you technically to attain the power source you need.

Nando

[Nando]

JEDON:

Indeed, you could obtain a much greater power from the 1100 feet away site, do water volume and head measurements and pipe length ( measuring where the pipe should be installed)

Supply the data to determine the available power

Power transmission No problem if sent via high voltage.

Inquire carefully about what can be done there and may be using not more than 1/3 of the volume you may harvest a good power source, making sure that you return the water to the same stream.

There are ways to protect the piping from freezing and still produce power in winter time.

One would be to bury the pipe below freezing point.

Nando

[Jedon]

I imported my GPS data into Google Earth to get a better idea of distances and elevations. The closest and easiest run is the spring that has about 61 feet of head not 100 like I thought and it's quite a bit further away than I estimated, the top of the spring is 430 feet from where the solar/batteries will be and the bottom of the run where the hydro power would be is 1000 feet away from the batteries.

The larger source of water is 2380 feet away. I'll measure the water flow tomorrow.

-Jedon

[Jedon]

I measured the stream on Sat and good news! I was able to fill a 4.25 gallon bucket in 3.17 seconds. I tried it about 6 times to make sure and got anywhere from 3.15 to 3.2 seconds so I think 3.17 is a good average. That would be 1.35 gallons per second or about 80gpm. Seems like perhaps I could use about half the water in order to preserve the ecology of the stream bed as well as for aesthetic reasons and still get 40gpm x 60' head / 10 = 240KWh?

-Jedon

[alancorey]

> 40gpm x 60' head / 10 = 240KWh?

Nope.  240 watts (no time unit).  So in 24 hours you'd get 0.240 * 24 = 5.76 KWh or 172.8 KWh/month.  You've got about 10 gpm less than I've got, and about 10 feet more head, so the estimated wattage is the same.  

The next question is how long a pipe run do you need from the top to the bottom to get that much head?  That's where the "net head" comes into effect, where you need to look at friction losses in the pipe.  My run is about 400 feet, and from the tables in the Scott Davis book I should be running 3 inch pipe for 50 GPM to keep friction reasonable.  I'd love to find equations for the friction rather than relying on tables in a copyrighted book.  Because your flow rate is a little less than mine and you've got more head you might get by with smaller pipe.  I'd be losing over 50% of my net head if I dropped the pipe size to 2 inch.

The county regulation you mention may be a factor here as well.  Looks like it's too rocky to think about burying the pipe.  It might not freeze if the water's moving fast in it, but it would be visible.  I have both problems here too, that's why I'm still thinking it over.  The concept of global warming needs to sink in and then authorities might be glad to let you do anything that might help, instead of standing in the way.

  Alan

[Jedon]

I had just come back to the post to correct my KWh vs watts, thank you for the clarification! That picture is of a larger water source I don't really want to consider right now since it's further away and like you say the county might not like it. The spring I speak of has a run of about 560 feet to get 66 feet of head.

I've heard of using a used firemans hose instead of PVC, sounds interesting!