Off Grid and on Grid 120v vs 240v efficiency with Sol Ark without Net Meter

[byteharmony]

My sol ark is reporting about a 5x% efficiency and I wanted to share this information for educational purposes. Not because sol ark or anything is wrong with my system.

There are a couple photos attached.

You can see my panel is not balanced at all. I draw a lot more on one 120v leg than the other. I also can not export until my system passes inspection. Please correct me if I'm wrong, but I believe once I am net metered the excess on one leg will be sold to the utility.

So if I have enough solar / battery production power I don't pay the utility. That has dropped my bill by about a hundred or two hundred dollars a month. I'm not going to work on figuring out exactly how much as I hope the net meter will change everything.

I just hoped this info could help people who are off grid and would benefit greatly having a balanced 120v load or understanding how important net metering is.

 

[niktak11]

That "efficiency" number is simply the incoming PV power divided by the stated PV array size. It has nothing to do with the inverter efficiency or unbalanced loads.

 

[byteharmony]

That "efficiency" number is simply the incoming PV power divided by the stated PV array size. It has nothing to do with the inverter efficiency or unbalanced loads.

Do you have any information about the efficiency of balanced vs unbalanced loads?

 

[zanydroid]

Please correct me if I'm wrong, but I believe once I am net metered the excess on one leg will be sold to the utility.

Not quite. There shouldn’t be any per leg excess until grid tied… and when grid tied the leg imbalance doesn’t matter. The inverter when exporting would just push power on both legs up to the export limit. The utility transformer will do a lot of the work of balancing the neutral current.

Efficiency of balanced vs unbalanced is hard to analyze. It’s probably irrelevant because this is probably a HF inverter arranged as two stacked 120V inverters (someone who owns this can correct me). The analysis would involve asking SolArk what the efficiency curve for the inverters looks like at different loading scenarios.