In the dark on solar- start-up system for duck pond

[Connie]

I'm completely lost and receiving mixed information on the next steps from various resources. I had a pond installed for a group of "unloved" ducks and under the advice of the pond builder, purchased various equipment in the hopes of powering the pump to keep water moving and somewhat filtered through totes. The system (attached) is only working for about 3 hours total daily. I live in sunny FL, seems to be pulling over 12 according to the controller for most of the daylight hours. I would like to run the system 24/7 and am doing so off the electric power now, but it's costing a lot! I contacted Renogy (most equipment is from them) and spoke to a representative who indicated I needed a ton more batteries. The next call (different person), said I needed more panels. Yet another said I should look for a different pump. Who is right?

The pump is working hard, and although I can't find the actual watts used per hour, the specs seem to indicate around 600 per hour?

Not sure where to get good direction to do the right thing. I hate to give up, but I don't have any knowledge on this equipment and live in a remote area where there doesn't appear to be anyone with experience in solar. I've attached a file with the equipment purchased, now 6 - 100 w panels and 2 AGM 12V Batteries and controllers, etc.

Where do I go from here? This is a tiny system, only looking to support the pond pump, but has become very discouraging.

Looking forward to input on what to do as its way over my head!

 

[BryceFreeman]

Hi, how many AH do the batteries have?
If the pump needs 600w power per hour, I think running 3 hours is quite normal for the solar system you have now.
6*100w panels can produce up to 600w per hour and we often calculate the sunshine as 4h per day.
It is out of the question if you want the pump keep working for over 12h with the existing solar system.

 

[Connie]

Thank you Bryce for your time in looking at my situation. I have (2) Renogy Deep Cycle AGM Batteries, 12 Volts - 100AH each, 3% self-discharge rate, 2000A Max discharge current (info taken from the order). It sounds like my system is way under what is needed to run this pump, especially it I try to do so 24 hours a day. What would your recommendation be for equipment to run 24/7 please?

 

[rodrick]

If the pump draws 600 watts you only have 2 hours of run time with those batteries if you want them to have any life expectancy don’t draw them down below 50% charge also the panels are not going to produce their maximum on a regular basis so that has to be accounted for so you need a lot more battery and panels

 

[MichaelK]

It is not realistic to expect that 600W of panels are going to produce 600W. That's not what happens in the real-world. In the actual field-testing of Renogy panels, I find they need to be de-rated to ~85% of nameplate output for operation in the real-world. Remember, that panel specifications are generated in an artificial test chamber under artificial light at exactly 1000W/square meter.

To compensate for less than optimal sun angle throughout the day, I normally recommend 2X the panels of whatever the load is. So, to properly support a 600W load, you really need ~1200W of solar panels.

Connie, which controller do you have? If you have only Renogy's PWM controller, you must wire all your panels in parallel. With an MPPT controller, you'll improve your efficiency because multiple panels can be wired in series to reduce wire resistance. The MPPT controller will also optimize the number of amps going into the batteries.

The reality here is that everyone is partially right. You do need more panels, and you do need a larger battery bank. Supporting a 600W load 24/7 however is not realistic. Assuming you want to run on battery at least 12hr per day, and you don't want to deplete your AGM batteries more than 50%, then the math for the size of your battery is.... (600W X 12hr X 2X)/12V = 1200Ah. You need a battery bank six times larger than what you have now.

Now, are you sure your pump specification is 600W/hr? Could it possibly be 600 gallons/hr? Lots of important details are left out of your original post. A full list of all your equipment would be very helpful.

An alternative solution might be to switch to a different pump controlled by a solar pump controller. You only need three items, the pump, the controller, and the panels, with no battery. In the early morning, the pump runs very slowly, or not at all. As the sun gets higher in the sky, the pump runs faster, maxing out at noon. Finally, as the sun drops in the afternoon, the pump shuts off again. This potentially might solve your pond problems without the expense of a full-sized battery system.

 

[Connie]

If the pump draws 600 watts you only have 2 hours of run time with those batteries if you want them to have any life expectancy don’t draw them down below 50% charge also the panels are not going to produce their maximum on a regular basis so that has to be accounted for so you need a lot more battery and panels

Thank you Rodrick for your reply. I'm learning that I either need to purchase a lot more equipment or settle with the higher electric bill!

 

[Connie]

It is not realistic to expect that 600W of panels are going to produce 600W. That's not what happens in the real-world. In the actual field-testing of Renogy panels, I find they need to be de-rated to ~85% of nameplate output for operation in the real-world. Remember, that panel specifications are generated in an artificial test chamber under artificial light at exactly 1000W/square meter.

To compensate for less than optimal sun angle throughout the day, I normally recommend 2X the panels of whatever the load is. So, to properly support a 600W load, you really need ~1200W of solar panels.

Connie, which controller do you have? If you have only Renogy's PWM controller, you must wire all your panels in parallel. With an MPPT controller, you'll improve your efficiency because multiple panels can be wired in series to reduce wire resistance. The MPPT controller will also optimize the number of amps going into the batteries.

The reality here is that everyone is partially right. You do need more panels, and you do need a larger battery bank. Supporting a 600W load 24/7 however is not realistic. Assuming you want to run on battery at least 12hr per day, and you don't want to deplete your AGM batteries more than 50%, then the math for the size of your battery is.... (600W X 12hr X 2X)/12V = 1200Ah. You need a battery bank six times larger than what you have now.

Now, are you sure your pump specification is 600W/hr? Could it possibly be 600 gallons/hr? Lots of important details are left out of your original post. A full list of all your equipment would be very helpful.

An alternative solution might be to switch to a different pump controlled by a solar pump controller. You only need three items, the pump, the controller, and the panels, with no battery. In the early morning, the pump runs very slowly, or not at all. As the sun gets higher in the sky, the pump runs faster, maxing out at noon. Finally, as the sun drops in the afternoon, the pump shuts off again. This potentially might solve your pond problems without the expense of a full-sized battery system.

Thank you Michael for the detailed response. I truly appreciate your time. I did create a full list of what I had (this site asked for it when registering) and I have attached here for your review. I have never heard of a solar pump controller! I live in FL, so usually get a lot of sun. There's fish in this pond currently and the water cycles down a "river" to a waterfall pond into the pond which provides some aeration and movement for the fish and also keeps water flowing over the vegetation that is growing in the river. Not sure if that needs to be running 24/7 or if a shorter time period would work. Anxious to find a solution as the pump has had a large impact on my electric bill! In looking at the math for batteries, 6 times larger than what I have now would be a total of 12 batteries? I need a bigger shed and pocketbook!