Long distance to Pressure Pump.

[mungewell]

Hi all,

I'm in the process of design a solar home (passive with PV for power), at present the design consists of a house sited further up a hill from the garage/workshop, which will house the batteries/invertors/etc. I intend a long 120V AC run from garage to power the house.

My understanding is that 12V DC pumps are much more efficient than 120V AC when it comes to pumping, so it make sense (to me anyway :-) to the locate the pressure pump in the garage and then run a 200ft pressured water line to the house.

As the house is higher than the garage I would expect a lower pressure at the house, but this is acceptable.

Does anyone see any problems with this arrangement?

Cheers,

Simon.

[deerslayer660]

  watch manufacturs  lift rateings so water doesnot get to heavey for the pump

george

[alcul8r]

Are you sure you want to go 12 V?  Find the inverters, charge controllers, etc, that you want to use.  You might find you want to go 24 or 48v.  The wires for 12v will be much thicker than for the higher battery voltages.

Rex

[mungewell]

Yes,

I meant 12, 24 or 48 V DC as PV setup dictates. All DC wiring will be contained within garage so runs shouldn't be too long.

I'm considering MPPT to squeeze the most out the panels, I feel that my site I too windy to have trackers... and  yes a windmill is planned for a future time.

Simon.

[ghurd]

Read some independant reviews of MPPT controllers.

My opinion is generally the MPPT money is better spent on more panels, for more power all the time instead of just sometimes.

They could be OK if the system is quite large.  I never put a system in large enough to have a MPPT that would gain nearly as much as the same money spent on more panels.

A quote from windsun.com.  And they are trying to sell them!

""Some MPPT's on the market don't give you as much you would hope for. The reason is efficiency. So you gain 25% by adding a MPPT - that does not help you much if your MPPT is 85% efficient. You've only gained about 5 watts - not much to get excited about...""   ""$500 to $1200...""

$500 to $1200 gets a lot more than 5 watts of panel!

The extra PVs will last what, 50 years? Who knows. But I can't see a high percentage of fancy controllers going even close to that long.

G-

[Bryan1]

Hiya Munge,

           You say that your house is higher than your shed so is your house on top of the hill???. I would suggest using a hydraulic water ram to pump the water to a header tank but if the high allows you could gravitate the water(just a thought)' or just place your pressure pump beside the tank, you'll find the pump will run alot cooler and use less power. The problem with 12 volt motors is the amperage draw and trying to pump a decent head with a 12 volt pump could draw more than 30 amps out your battery anyway I'm in the process of making up a water ram using 2" poly fittings to pump water from the back of my place to my front dam

 see my thread at (http://www.fieldlines.com/story/2004/12/17/23323/946).

   If I can help out more Id be glad to.      

Cheers Bryan

[mkseps]

Assuming that you go the 12 volt route.  At 200 feet, you will have to provide wiring heavy enough to provide the starting inrush of the motor.  I would suggest this:  Provide the necessary wire for the motor running current.  Insert a power diode in one of these lines so the motor must get its power through this diode.  Now on the motor side of the diode, you place a garden tractor battery.  Now when the motor kicks in, the battery supplies the inrush.  When the motor stops, the battery is recharged through the diode using much smaller cables.

Gene