Solar & Pump without battery?

[Roadeater]

Hi to all the knowledgeable sparky types.

Looking for an answer to my conundrum. Now I don't know peas from pods when it comes to electrical stuff so I'm stuffing my pride and asking for help.

You see, I go camping at a little bush block in the Flinders Ranges and there's this old well that I'm trying to pump water from to a header tank set-up at an old shack. I have a solar panel (190W) and a 24v DC pump that I want to connect direct with an in-line regulator of some type. Now I know that the panel will put 50+ volts in the sun and the pump will burn out super quick at that, so I need to know what sort of regulator I need? I also don't want to run a 24v battery set-up with a controller as I really don't want to haul batteries or go too complex.

So in summary, what sort of voltage regulator - batteryless - can I connect to keep a constant 24v while I have the solar connected to the pump?

Any pictures or links will be appreciated. I don't know any electrical type mates to ask their advice so I'm here at one of the best sources of info that I know.

Cheers, Greg.

 

[Old.Tony]

I wouldn't be too concerned about it at all. The rated voltage of the panel is measured when it's unloaded and they're notoriously high. 12V panels often read around 20-22V.

The 24V pump will be a typical wound motor. It won't actually hurt it by giving it a slightly higher jolt right at the start but if there's any other circuitry involved (pressure switch or digital pressure sensor) these could suffer.

I wouldn't leave it connected all the time, just when it's needed. If the solar panel isn't producing enough power to keep the motor turning over, it could be producing enough to heat it up and that's where failures can occur.

Of course it may not work under all weather conditions. Panels prefer bright sunlight, monocrystalline panels work better in lower light conditions than poly. You might then consider a battery and a charge controller. If the pump draws 5A and you can fill the header in 10 minutes, a pair of 7Ah gel batteries (in series = 24V) is enough to do it a few times before a recharge is needed. That, and an MPPT charge controller are nice and small so you could take them away with you and store them behind the seat.