Solar Water Pump Issues

[Tigersnake]

I recently bought a submersible 15 meter maximum head height pump. The maximum power rating for the pump is 370 Watts and the voltage is 12 to 24 volts and it has no need for an external control box (regulator). It performs at a maximum pressure of 1.2 bar. I bought a 330 Watts monocrystalline solar panel for the pump. My well is at least 6 meters deep (water level) and the pump is connected to a 50 meters 15 mm hosepipe at the outlet. This is for my garden.

The water is coming out of the other end of the hosepipe but it's minimal flow and it requires some sucking assistance with my mouth to actually start coming out. From the manufacturers pump curve (which I have attached) it should be able to easily pump from what I was expecting (from my understanding).

What might be the problem? If there is one. How can the situation be improved?

I was thinking about adding an extra 100 Watts solar panel to make it 430 Watts total but someone has advised me not to do that because it might damage the pump. Can't the problem be solved by adding an external voltage regulator to the system?

If there's a better way of dealing with the situation I would be open to hearing about it.

 

[TomC4306]

Not enough solar. Buy another panel an connect them in parallel.

Edit - buy another identical solar panel

 

[Tigersnake]

Not enough solar. Buy another panel an connect them in parallel.

I have a 100 Watts panel, is it safe to add that panel to the 330 Watts panel? Someone had said to me it's not advisable to mix panels of different sizes.

(Ok got it I need an identical panel)

 

[TomC4306]

Solar panels almost never make their rated Watts. And they must be pointed at the Sun. It is not daylight that energizes them it is 90° sunshine striking the panels that energizes them.

 

[TomC4306]

I have a 100 Watts panel, is it safe to add that panel to the 330 Watts panel? Someone had said to me it's not advisable to mix panels of different sizes.

Safe, yes. Advisable, no. The 100 watt panel will limit the 370 watt panel to 100 Watts

 

[Tigersnake]

Not enough solar. Buy another panel an connect them in parallel.

I have a 100 Watts panel, is it safe to add that panel to the 330 Watts panel? Someone had said it's not advisable to mix panels of different sizes.

Safe, yes. Advisable, no. The 100 watt panel will limit the 370 watt panel to 100 Watts

Alright I see, so it's best to add another 330 W panel, thanks. Will I need an external control box if I add another panel since the pump specs state 370 W max?

 

[TomC4306]

Electrical power is pulled by the load (pump) not pushed by the source.
Think about it this way. Your laptop power brick is rated for 65 Watts. But it's plugged into an outlet that can provide 1800 watts. It will only draw up to its maximum 65 Watts from the 1800 watt source.
Likewise, you're 330 watt pump will only draw up to its maximum 330 Watts from whatever rating the source is. If you only have one 370 watt panel connected, and there is a thin Marine layer of clouds, the single panel can only produce 200 Watts but your pump is rated for 370. Thus, the weak flow.

 

[TomC4306]

You'll also need a par of branch connectors.

https://www.amazon.com/BougeRV-Connectors-Branch-Parallel-Adapter/dp/B0753X68PS/ref=asc_df_B0753X68PS/?tag=hyprod-20&linkCode=df0&hvadid=198064505516&hvpos=&hvnetw=g&hvrand=16425116468711744548&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9008051&hvtargid=pla-359698458424&psc=1

 

[MichaelK]

Safe, yes. Advisable, no. The 100 watt panel will limit the 370 watt panel to 100 Watts

That's not exactly how it works. What the 100W panel will do is limit the amps flowing to that of the 100W panel. Let's say the 370W panel is putting out 10A at 37V, and the 100W panel puts out 5A at 20V. Combine them in a series string and what you will get out is 5A at 57V, or approximately 285W.

 

[Tigersnake]

Ari

Electrical power is pulled by the load (pump) not pushed by the source.
Think about it this way. Your laptop power brick is rated for 65 Watts. But it's plugged into an outlet that can provide 1800 watts. It will only draw up to its maximum 65 Watts from the 1800 watt source.
Likewise, you're 330 watt pump will only draw up to its maximum 330 Watts from whatever rating the source is. If you only have one 370 watt panel connected, and there is a thin Marine layer of clouds, the single panel can only produce 200 Watts but your pump is rated for 370. Thus, the weak flow.

Alright I get, thank you for explaining in layman's terms. So it's not a problem at all, it's actually better that way having a lot more energy from the panels. An extra panel of the same size is fine.

 

[Tigersnake]

R

That's not exactly how it works. What the 100W panel will do is limit the amps flowing to that of the 100W panel. Let's say the 370W panel is putting out 10A at 37V, and the 100W panel puts out 5A at 20V. Combine them in a series string and what you will get out is 5A at 57V, or approximately 285W.

I see, so the overall energy produced will be reduced, the two panels won't necessarily add up to 470 Watts.