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benniec avatar image
benniec asked

Powering a 220V 3kW inverter with solar panels and no battery

Hi I am looking for a solution to drive a 220V inverter for a load of 2-3kW directly from Solar Panels. Unfortunately all questions result in a complete battery assisted power solution. I only need power during sunlight and do not wish to buy expensive batteries, except maybe to support fluctuations if the controller needs. A MPPT charge controller of sufficient size appears to be the kind of product but they all need batteries. Any assistance in pointing me to the right direction will be appreciated.

MPPT Controllers
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klim8skeptic avatar image klim8skeptic ♦ commented ·
What is your load ?
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nickdb avatar image
nickdb answered ·

Get a PV inverter then. Multis and quattros all need batteries.

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benniec answered ·

Whenever I search for PV inverter I just get standard solutions requiring batteries. Can you please be specific, maybe a company or product name

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pwfarnell avatar image pwfarnell commented ·
Fronius for one.
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sharpener answered ·

Or SMA or Gro-Watt to name but two others.

However ordinary PV inverters are designed to work synchronised to the grid (or to the AC-Out of a MultiPlus or Quattro), they will not operate in free-standing mode, you need a specialised off-grid inverter for that.

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wkirby answered ·

I'm pretty sure the Fronius Gen24 Plus can make AC power from PV without a battery. 3kW from its backup outlet without a battery IIRC?

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sharpener answered ·

For most applications you would need really steady continuous sunlight for it to be useful. Even the OP writes "I do not wish to buy expensive batteries, except maybe to support fluctuations if the controller needs".

I assume that the Fronius will switch off gracefully if the load current demanded is more than the sunlight can produce instantaneously but even so there are not many loads that like being continuously stopped and started, the exception perhaps being a resistive dump load like a water heater.

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