wpns
Solar Joules are catch and release
Agreed, you get what you pay for.
Direct to PV pump, variable resistors, lions, tigers...
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efficientPV
Solar Addict
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The buck converter will take a higher panel voltage (16-21V) a convert that to higher current at 12V. That works fine till the pump is asking for more power than the panels can produce. At that point the panel voltage takes a nose dive. I believe the pump can take this situation as long as it is submerged to dissipate heat. The good part is pump voltage will never go above 12V.
That's helpful thankyou - I think I'm almost there on the rudimentals of this.
With the buck converter in place, is it the case that the pump motor (or other load) will only draw the current it needs (at 12v) and no more?
I think this is still the big gap in my knowledge here - can I use a panel with a higher wattage in such a circuit?
...or will it overpower the pump motor?
With the buck converter in place, is it the case that the pump motor (or other load) will only draw the current it needs (at 12v) and no more?
I think this is still the big gap in my knowledge here - can I use a panel with a higher wattage in such a circuit?
...or will it overpower the pump motor?
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wpns
Solar Joules are catch and release
That’s correct.
Quattrohead
Solar Wizard
You need to stop thinking about watts and instead think about the volts and amps that the motor actually requires. Then we can start recommending some kind of voltage regulation. The pump will only take as many amps as it needs but too many volts will blow it.
Thank you - a matter of volts - it's starting to click. I'd been thrown by internet guides suggesting to match panel wattage to load wattage in direct connection.
Provisional setups:
100W PV --------- 24-12v DC-DC --------- 12v DC Pump 35W (3 amps)
100W PV ----------24-12v DC-DC -----------12v DC pump (1.5 amps)
Recommendations for a suitable voltage regulator/converter (or a spec to look for) would be hugely appreciated.
A low voltage cut out strikes me as potentially useful feature here, but perhaps it's unneccessary.
Quattrohead
Solar Wizard
Ether of these would work, hope the links work as I'm on my phone
Perfect, thank you. I'll update when it comes together if anyone is interested.
wpns
Solar Joules are catch and release
Always like to hear how things turned out!
