Hi,This is the best I've seen.hybrid grid tied

Please elaborate how this benefits a solar powered RV?Are RV solar arrays so large that DC transmission is no longer practical?Is it common for RV parks to be set up to accept "sell back" supply into their AC distribution system?

Hi GordonThree,Thanks for asking!The main benefit is that it eliminates the charge controller.It deals with shaded panels dragging down the whole array.It saves on the cost of wire.It is modular so more panels can be added later without regard to their individual profiles.The inverter itself is hybrid. Nice to have full functionality on a 15 amp service.The potential is there to reduce electricity charges if in a long term site where power is metered.If you have a sticks and brick home, using the hybrid inverter might be able lower the power bill.

Hi Don,This is interesting technology... I'm still trying to understand some of the advantages.Is it really eliminating the charge controller, or just moving it? The microinverter is taking 48v panel voltage and boosting it to 240 volts AC. The Magnum inverter takes the 240 volts and uses it to charge the battery bank and power loads using the load-support feature. Does the Magnum handle step down for 120 volt loads? The installers freely admitted the microinverters were costlier than a conventional charge controller, plus what is the efficiency cost of the double conversion?Can the Magnum hybrid dual-source AC input? AC input 1 is the 240 volt PV array, AC input 2 is the park 120 volt 15 amp outlet? From the video, it appeared you need to backfeed the grid, and that backfeed connection is what the hybrid inverter is using for an AC input.With a conventional configuration, your solar is supporting the hybrid inverter by feeding the DC input, which works independently from any AC source available from the park.If I had a 2000 sq foot roof to cover with solar, I would consider the mircoinverter grid tie route, since high voltage low amperage transmission makes sense. Batteries would be optional at this point, as long as the utility gives credit for backfeed. Daytime grid input offsets night time draw. Using time based billing, the kwh cost drops at night as well. Sell high, buy low right?A big Class A RV only has a few 100 sq foot of roof surface available. So maybe they need to run 60-100 volt DC to save on wire. I suppose working with high voltage DC is beyond the means of inexperienced DIY? High quality MPPT controllers accept up to 150v PV voltage, that's quite a large array.Very interesting discussion!

Hi Gordon,It does eliminate the charge controller. All charging is done by the inverter.Magnum does make a 120 volt model hybrid model--and for a 50 amp RV one would want the 240 volt split into two outputs.I suspect that for 4 panels @ 320 watts each that the micro inverters are cheaper than a charge controller. But of course, I don't know that for sure.

How does the inverter select the AC source. Can the hybrid inverter draw from both the PV array and shore power at the same time, or is it one or the other? Assuming you're not backfeeding shore power... I don't know what RV park owner would give permission to backfeed, sounds like a liability nightmare?Thinking more, the inverter must control the backfeed, to prioritize it ... charging batteries is higher priority than selling to the utility I would guess?

A grid tied hybrid system that could be used on an RV!

26 Replies

pianotuna
Nomad III
Jan 21, 2018
Hi MrWizard,

No, for this particular iteration of grid tied no external power (from shore power) is required for the unit to continue to produce power. The reason for that is that the inverter is a hybrid model. It is designed to continue to work when the grid goes down.
valhalla360
Navigator
Jan 21, 2018
So the charge controller is integrated in with the inverter.

I really don't see much use in an RV application.
GordonThree
Explorer
Jan 21, 2018
MrWizard wrote:
take the output from the micro inverter, and connect to the rv house 120v and power the converter ?

the trouble with grid tie micro inverter is the same as any other Grid tie
it must be connected to 120v supply and sync to it

no exterior 120v,it shuts OFF, no output

How would that be helpful if you're dry camping then? Run a generator to kick the grid tie on?

I'm completely lost on this subject. Why grid tie, why microinverter for an RV?
MrWizard
Moderator
Jan 21, 2018
take the output from the micro inverter, and connect to the rv house 120v and power the converter ?

the trouble with grid tie micro inverter is the same as any other Grid tie
it must be connected to 120v supply and sync to it

no exterior 120v,it shuts OFF, no output
GordonThree
Explorer
Jan 21, 2018
I give up then. Just wanted to know how you charge batteries with a microinverter without backfeeding shore power, but I guess that's a secret.
pianotuna
Nomad III
Jan 21, 2018
GordonThree,

I think it is on the supply side of the inverter.
GordonThree
Explorer
Jan 21, 2018
So the PV is attached on the house side of the inverter rather than the shore side?
road-runner
Explorer III
Jan 21, 2018
Duplicate posted by mistake.
road-runner
Explorer III
Jan 21, 2018
The charge controller is eliminated as a separate module. Its function remains, moved to the main inverter and microinverters. This is a nice technology jump from previous AC coupled systems, where there had to be added hardware to disconnect the microinverters or kick in a diversion load when the battery was charged and there was excess solar power. It looks like now the main inverter can tell the microinverters to throttle their output as needed. Pretty clever about adjusting the frequency. Some older systems changed the frequency to kick the microinverters totally off. Using the frequency for throttling is new (to me, anyway). Load support is a totally different feature.
GordonThree
Explorer
Jan 21, 2018
So it can use the 240v PV array to charge batteries while running load support on shore power?

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A grid tied hybrid system that could be used on an RV!

26 Replies

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