MPP LV2424 grid-tie mode efficiency

[ohseedee]

I bought an MPP LV2424 for backup reasons during a power outage, but I’ve been experimenting with the grid-tie feature. Everything seems to be working fine, but I’m outputting about 40% of the Power I’m generating from solar. I’m currently generating about 500 watts via my solar setup, but my MPP is only showing a little less than 200 watts of load. I have nothing plugged into the inverter output and my battery is just maintaining a full charge at about 1 or 2 amps Charge from solar (so thats about 24 or 48 watts). As such I’d expect at least 400 watts being fed back into the grid. Also, I’m only relying on the load reading on the MPP. I tried at Watt meter, but it didnt play nice with grid-tie and gave an ”Overload” message (if anyone has suggestions on a watt meter that would work with grid tie let me know that too). So I’m not sure if the reading is right or this is about what i can expect in terms of efficiency. Another interesting thing i noticed is that if i put a 100 watt load on the utility powered outlet that I’m using for grid-tie I see the load on the MPP go down by about 20 watts, which makes no sense to me. So leads me to think the load reading isn’t an accurate way to see how much power is being fed back into the grid.

Using this for grid-tie long term is not my intention as I don‘t want to do anything unsafe (It’s not even plugged in right now), but I’m just experimenting while on lock down...

 

[kxy]

Any updates on your findings, I am getting similar results.

 

[madmax]

clamp meter?

 

[Xerxes]

Is that a split phase unit?
Were you trying to grid tie at 230V or single phase 110V?
I do not have this unit, just guessing a path.

Last, I have to condemn you for violating rules, laws, and safety concerns for doing such a thing without the proper inspections and permitting.
There are several safety reasons as well as concerns for equipment of your utility and neighbors when you do something like that.

 

[kxy]

@ohseedee ,

You might be over voltage your lv2424, at least that is the case with mine. Try connect your solar panels in parallel configuration.

 

[ohseedee]

I did end up installing a permanent clamp meter on the AC input to monitor the energy being fed back to the grid. It shows a little higher watts, but still way under what I'd expect. The lv2424 shows maybe 160 watt load while the meter shows ~200 watts when solar is producing about 500 watts and charging the battery at about 1 or 2 amps. Since the primary purpose for this system is for backup power during an outage + power some outdoor appliances (e.g. pool pump), I have not really worried too much about it.

kxy - Interesting thought on the over voltage. However, the watts are coming in and are displayed correctly screen, why would solar over-voltage have an impact on AC output? I have 6 100 watt panels in series, which is usually around 100 volts and pretty close to the max. I could get a higher gauge wire and try them in parallel (don't want more amps on my current wire). Probably not something I'm going to do tho unless I decide to get a couple more panels in the future.

Xerxes - I get it...but this unit does shut down when the power goes out. I've tested it and it does work as advertised in that department.