Summer Project Help: Solar Powered Pool Pump


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BinaryData

Hey Guys,

 

So, my family members asked the impossible of me.

We're building a pretty big pond, enough to put several koi in it. Well, where we live we have a massive problem with mosquito's (Not like the Mid-US).

 

 

I've never done anything like this before, and I'm looking for help. This is what is needed...

Solar Power Absorbing Thingy ----> Pool Pump
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Back Up Battery for at Night

 

 

This size of a Pool Pump

 

I have the pool pump already, picked it up at a yard sale for 10$ with the full pool setup. Pool doesn't work for my family, because we're all freaking giants.

So where can I find the solar panel (It'd be on my roof).

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Astra.Xtreme

Is there any reason why you want to run it on solar as opposed to plugging the pump into a 115V outlet on your house?  If the solar panel is going to be on your roof, you're going to have to run wiring anyway.

 

The reason why I ask is because it's going to be really expensive.  Most likely several thousand dollars.  Solar panels typically output 12VDC, so to get 115VAC, it requires an expensive inverter.

 

Running the pump with sunlight won't be a problem.  Assuming the pump is rated at 115V and 2.5A, it will require 288W of power.  Add on 20% efficiency loses and it gets bumped up to roughly 350W.   Not too big of a deal.  Recalculate all of this with the Amp rating of your pump.

 

When you don't have sunlight, it's going to take a ton of battery capacity to keep it running.  In Washington you get an average of 5 sun hours where you can pull good energy. For the remaining 19 hours, it will take 3,150 Watt-hours to keep the pump running.  At 115VAC, it will take a battery bank with a capacity of 27.4 Amp-hours.  I don't know what your loses will be when you invert the 12VDC battery voltage into 120VAC, but it's going to take a monster battery bank to make it work.  It's probably not even worth trying to keep the pump running without sunlight.

 

Something like this might get you close:

http://www.homedepot.com/p/Grape-Solar-400-Watt-Off-Grid-Solar-Panel-Kit-GS-400-KIT/203505963?N=5yc1vZbm31#specifications

 

It's rated for 400W, but that's at 18VDC, so I'm not sure what the output is on the 115VAC inverter.

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BinaryData

Is there any reason why you want to run it on solar as opposed to plugging the pump into a 115V outlet on your house?  If the solar panel is going to be on your roof, you're going to have to run wiring anyway.

 

The reason why I ask is because it's going to be really expensive.  Most likely several thousand dollars.  Solar panels typically output 12VDC, so to get 115VAC, it requires an expensive inverter.

 

Running the pump with sunlight won't be a problem.  Assuming the pump is rated at 115V and 2.5A, it will require 288W of power.  Add on 20% efficiency loses and it gets bumped up to roughly 350W.   Not too big of a deal.  Recalculate all of this with the Amp rating of your pump.

 

When you don't have sunlight, it's going to take a ton of battery capacity to keep it running.  In Washington you get an average of 5 sun hours where you can pull good energy. For the remaining 19 hours, it will take 3,150 Watt-hours to keep the pump running.  At 115VAC, it will take a battery bank with a capacity of 27.4 Amp-hours.  I don't know what your loses will be when you invert the 12VDC battery voltage into 120VAC, but it's going to take a monster battery bank to make it work.  It's probably not even worth trying to keep the pump running without sunlight.

 

Something like this might get you close:

http://www.homedepot.com/p/Grape-Solar-400-Watt-Off-Grid-Solar-Panel-Kit-GS-400-KIT/203505963?N=5yc1vZbm31#specifications

 

It's rated for 400W, but that's at 18VDC, so I'm not sure what the output is on the 115VAC inverter.

 

Thanks for the reply. So what you're saying is, it'd be cheaper to run it from a wall plug, than a solar panel.

 

Well, that solves my problem. I can tell them it's too expensive, and I don't have the knowledge to work with SP.

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Astra.Xtreme

Thanks for the reply. So what you're saying is, it'd be cheaper to run it from a wall plug, than a solar panel.

 

Well, that solves my problem. I can tell them it's too expensive, and I don't have the knowledge to work with SP.

Yeah if you calculate the power usage, it doesn't cost too much.

For Washington, it looks like $0.09/kWh is typical.  So with 288W being pulled from the pump, it comes out to roughly 2500kWh per year if it's running 24/7.  At $0.09/kWh, your yearly cost is $225.  You could put the pump on a timer and not run it at certain times of the day to decrease that cost if you wanted.

 

But yeah, it's going to be way way cheaper to just use an outlet than installing a solar panel.  Solar is a good idea, but with something around a 10 year or more return on investment, it's a hard sell.

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BinaryData

Yeah if you calculate the power usage, it doesn't cost too much.

For Washington, it looks like $0.09/kWh is typical.  So with 288W being pulled from the pump, it comes out to roughly 2500kWh per year if it's running 24/7.  At $0.09/kWh, your yearly cost is $225.  You could put the pump on a timer and not run it at certain times of the day to decrease that cost if you wanted.

 

But yeah, it's going to be way way cheaper to just use an outlet than installing a solar panel.  Solar is a good idea, but with something around a 10 year or more return on investment, it's a hard sell.

I wanted to have it just be online during the day. Probably use a fish pump to move the water at night. I doubt I'd have problems with mosquito's over night, but I'm not an entomologist.

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