Dave
05-26-2009, 08:38 AM
I have a good friend of mine who is working on a mission farm in Haiti. They currently have 10 fish ponds that need aeration but each pond has a pump drawling 7 AMPS at 120V pretty much continuously. Power in Haiti is unreliable to put it nicely.
They are discussing the possibility of replacing all of these pond pump systems with solar power solutions.
There are two trains of thought here.
1) Use the in place 120V AC pumps and replace grid power with solar and inverters.
2) Replace the AC pumps with DC pumps to potentially reduce requirements and complexity (We are talking about a 3rd world nation).
Obviously there are lot of variable here. My goal is to help my friend put together the most cost effective but reliable system as possible. They are hoping to increase the yield of the current system so they can literally feed more kids who depend on the food supply from this farm.
Quite literally, the overall success of this project will save lives.
I couldn't think of a better place where I could post this question and hope potentially come up with a workable and affordable solution. The people involved in this mission are literally funding this project out of their pockets.
So far here is what I have calculated using the current 120V Pumps:
120V electric pumps, a 7AMP drawl at 120V would equate to 840 Watt/hrs. 840 Watts at 24 hrs a day would equal 20,160 Watts total consumption every 24 hours. Additionally, 7 AMPs would drawl about 175 AMP hours through the course of the day meaning your should have a battery bank capable of ideally 700 AMP Hours (considering you lose about 10% of your power in the DC to AC conversion process).
Naturally, you will require a solar array large enough to replenish the total used power. Assuming you have 8 hours a day of peak sun light, you would need to generate 20,160watts / 8hrs = 2520 watts per hour. This is a pretty sizable solar array because you have to account for "cloudy days" in your calculations.
Your battery array would likely consist of 8, 6V 175AH (or greater) batteries with two sets of four batteries wired in series and then combined in parallel in create 24VDC to your inverter.
This system could be pretty costly when you consider you are doing this 10 times for each pond.
Thank you!
Dave
They are discussing the possibility of replacing all of these pond pump systems with solar power solutions.
There are two trains of thought here.
1) Use the in place 120V AC pumps and replace grid power with solar and inverters.
2) Replace the AC pumps with DC pumps to potentially reduce requirements and complexity (We are talking about a 3rd world nation).
Obviously there are lot of variable here. My goal is to help my friend put together the most cost effective but reliable system as possible. They are hoping to increase the yield of the current system so they can literally feed more kids who depend on the food supply from this farm.
Quite literally, the overall success of this project will save lives.
I couldn't think of a better place where I could post this question and hope potentially come up with a workable and affordable solution. The people involved in this mission are literally funding this project out of their pockets.
So far here is what I have calculated using the current 120V Pumps:
120V electric pumps, a 7AMP drawl at 120V would equate to 840 Watt/hrs. 840 Watts at 24 hrs a day would equal 20,160 Watts total consumption every 24 hours. Additionally, 7 AMPs would drawl about 175 AMP hours through the course of the day meaning your should have a battery bank capable of ideally 700 AMP Hours (considering you lose about 10% of your power in the DC to AC conversion process).
Naturally, you will require a solar array large enough to replenish the total used power. Assuming you have 8 hours a day of peak sun light, you would need to generate 20,160watts / 8hrs = 2520 watts per hour. This is a pretty sizable solar array because you have to account for "cloudy days" in your calculations.
Your battery array would likely consist of 8, 6V 175AH (or greater) batteries with two sets of four batteries wired in series and then combined in parallel in create 24VDC to your inverter.
This system could be pretty costly when you consider you are doing this 10 times for each pond.
Thank you!
Dave