How many panels do I need?

[thedjwcc]

I am trying to find out how many panels I need to power a motor that runs a high elevation water pump. I am currently using a gas motor for the job, but have been trying to find out what I need to power the electric motor that I have to get the job done. No luck from any where, hope you guys can help me out.

Heres what I am trying to power: It is a 1/2hp 12VDC motor with 39 Full Load Amps. From my calculations, .39 hp is required to do the job, if that helps figure out actual power consumption, i havent tested the system to see how many amps are actually being pulled while running.

It does not need to run at night or when there is not sufficient sunlight, but I would like for it to run continusouly when sunlight is avaliable. Ideally for 8 hours per day for two consecutive days, but which is not completely nessicary. From my calculations (W = V x A) I will need 468 Watts to power it continusly during the day. This means two 250 watt panels with a couple batteries should do the job??? Thanks for your help!

[inetdog]

I am trying to find out how many panels I need to power a motor that runs a high elevation water pump. I am currently using a gas motor for the job, but have been trying to find out what I need to power the electric motor that I have to get the job done. No luck from any where, hope you guys can help me out.

Heres what I am trying to power: It is a 1/2hp 12VDC motor with 39 Full Load Amps. From my calculations, .39 hp is required to do the job, if that helps figure out actual power consumption, i havent tested the system to see how many amps are actually being pulled while running.

It does not need to run at night or when there is not sufficient sunlight, but I would like for it to run continusouly when sunlight is avaliable. Ideally for 8 hours per day for two consecutive days, but which is not completely nessicary. From my calculations (W = V x A) I will need 468 Watts to power it continusly during the day. This means two 250 watt panels with a couple batteries should do the job??? Thanks for your help!

Problem number 1: Light enough to see by is not light enough to produce rated output from a solar panel, even if you use a tracker mechanism to keep the panel aimed directly at the sun. Depending on your location, you may only get 4 or 5 "solar hours" of light in the middle of summer unless you use a tracker. In winter, it will be a lot less.
Problem number 2: Even then, you are not likely to get 250 watts from a 250 watt nominal panel.
Problem number 3: Not all of the panel output will be effectively delivered to the batteries. More power will be lost with a PWM controller than with a more expensive MPPT controller.

All of this can be taken care of by using more panels and larger batteries. But to get decent life from the batteries, you should not discharge them beyond the point where they can be recharged by the panels during the next 1 or two days.
Lots more details are involved with the design, but a good place to start is to tell us your geographic location or you can look at pvwatts.

[green]

Do you have grid power available? Much cheaper to just plug it into a 12V power supply.

Green

[inetdog]

Do you have grid power available? Much cheaper to just plug it into a 12V power supply.

Green

If OP is currently using a gas engine, chances are he does not have grid power available.

[green]

If OP is currently using a gas engine, chances are he does not have grid power available.

One thing I've learned in life is you can't assume anything. Figured it needed to be asked because I've seen stranger things around here.

Green

[thedjwcc]

No, there is not grid power near the site for about a mile, which would cost a lot more to run than any solar operation. Here is the data that I pulled up off of pvwatts that is closest to the location. This information is about 150 miles from where the site actually is. The actual elevation at the site is right above 6000 ft. I dont understand the best way to construct this solar operation. Is there a device that will shut down the power supplied to the motor if it begins to get too low automatically so that you dont have to stand around and wait for the sun to set? We usuially just let the motor run out of gas to shut it off. It would be fine if the motor ran only at useful solar hours during the day when power can be supplied adequately possibly avoiding having to use batteries all together.




Station Identification
City: Albuquerque
State: New_Mexico
Latitude: 35.05° N
Longitude: 106.62° W
Elevation: 1619 m
PV System Specifications
DC Rating: 4.0 kW
DC to AC Derate Factor: 0.770
AC Rating: 3.1 kW
Array Type: Fixed Tilt
Array Tilt: 35.0°
Array Azimuth: 180.0°
Energy Specifications
Cost of Electricity: 8.7 ¢/kWh

Results

Month Solar Radiation
(kWh/m 2/day) AC Energy
(kWh) Energy Value
($)
1 5.33 505 43.93
2 6.06 506 44.02
3 6.44 594 51.68
4 7.16 611 53.16
5 7.40 633 55.07
6 7.10 573 49.85
7 7.13 592 51.50
8 7.02 588 51.16
9 6.71 549 47.76
10 6.55 578 50.29
11 5.73 508 44.20
12 5.14 488 42.46


Year 6.48 6726 585.16

[Sunking]

Here is what you will need to generate a minimum 4 Kwh/day minimal year round production :

Panel wattage = 1200 watt
Midnite Solar Classic 150 80 amp MPPT Charge controller
12 volt 1600 AH battery like 6 units Rolls 2KS33PS

[Naptown]

Slow down folks there are well systems that run entirely off of solar without batteries.
The big questions here are how deep is the well, how much water do you need daily, is there overhead storage for the water, if so how much higher than the well level this is and can you use gravity to feed the end use.

[thedjwcc]

Slow down folks there are well systems that run entirely off of solar without batteries.
The big questions here are how deep is the well, how much water do you need daily, is there overhead storage for the water, if so how much higher than the well level this is and can you use gravity to feed the end use.

The setup runs off of a 6000 gallon storage tank, it pumps the water for about a mile and a half with an increase in elevation of about 600ft to another storage tank. The system that's on it is a high pressure water pump with a gas motor on it. I have looked at just tying an existing solar well system into the line, but I've yet to see one that will even do 200 head ft of water. The closest solution I have found is putting the, said from previous post, electric motor in place of the gas motor. I would like to use the same concept as those systems with a minimal cost that will work effectively when the sun is shinning.

[Wy_White_Wolf]

Lots of pumps here that will do over 200' of head.

http://www.backwoodssolar.com/catalog/pumps.htm#SOLAR_SLOWPUMP

WWW