Looking to supliment (not bypass) shore power with solar

[Fleet204]

Long time fan if Matt's vids. 1st post.

I know this is possible, but the application is so odd, I cannot google or youtube a good tutorial or parts list to confirm. Hoping a generous soul can offer some advice.

I have purchased a campsite... well, the site is leased year to year, but this campground allows structures to be built. So in essence I have a 20' Jayco Trailer connected to a small cabin + shed.

The old owners had a janky electrical set up. I want to use a proper sub panel and dedicated breakers to the few plugs, a/c, and the trailer rather than everything relying on the main breaker from the shore power plug.

Getting to the question, I promis. The camp site is provided with 120v/30a of shore power. This is included in the lease price, so reducing my "grid" consumption is not the goal here... quite the opposite, I want to use that as 1st priority.

I want to supply the camper and Cabin (and shed) with more available amps than the 30 provided by shore power, in case there is a temporary need.

If total consumption is under 30a, then I am just drawing from shore power. But, if combined use of power were to exceed 30a, or there was a brief surge, the solar/inverter/batteries would cover for this.

Ideally, when loads are under 30a and the batteries are not fully charged, the shore power would charge the batteries. If there is no good sunlight in my location, I may not even use solar panels at all (GASP!) and rely on the provided shore power to keep a battery bank charged up when there is extra to spare.

I feel a hybrid all in one is the way to go, but I cannot confirm it for sure. All the vids and articles focus on grid tied systems (I will tie to shore power but must not back-feed), transfer systems (the batteries could act as power if the shore power goes out, but I want to combine the power, not switch between it), or off-grid which does not apply here.

Ideal set up:
AIO hybrid, accepts 120v/30a AC, 12/24v DC from battery bank, supplies a single 50 or 60a 120v ac which I feed to sub panel, AIO charges batteries from grid or if possible depending on available sunlight, solar.

Am I correct that I need an AIO hybrid rid and if so, any suggestions on one that would fit in my ideal set up? Am I going to just burn off lot of idle power running an inverter doing this?

Thanks for any advice.

 

[SamDeleted]

Isn't this kind of power supplementation available on some victron inverters ?

Normally used for supplementing bigger loads from smaller generators

Eg. 1kw geno, 2kw of load , victron will split the load between generator and it's batteries

Not sure this would work for you, just an idea

 

[rodrick]

If your not doing pv a inverter charger is all you need

look at a victron multiplus or some of the other tier 1 units

and you would have a grid assist not grid tied and if power went out your battery would supply your power

 

[timselectric]

Yes, some Victron models have grid assist mode.
I don't know of any other manufacturer that does.
Normally, solar is prioritized. And the grid is only for backup. But grid assist takes just what's available from the grid source and supplements it with solar and/or battery.

 

[Fleet204]

Thanks for the ideas above. This feature shows some promise (from a Victron MultiPlus inverter/charger):

PowerAssist - Boosting the capacity of shore or generator power
This feature takes the principle of PowerControl to a further dimension. It allows the MultiPlus to supplement the
capacity of the alternative source. Where peak power is so often required only for a limited period, the MultiPlus will
make sure that insufficient shore or generator power is immediately compensated for by power from the battery. When
the load reduces, the spare power is used to recharge the battery.


I will update if I proceed or learn anything else.

 

[Hedges]

Also works with Sunny Island. Some on eBay around $2500.
120V, 5.75kW inverter. You can program for 24A max draw (80% of 30A breaker) to avoid tripping, and it would draw from battery to supply more current when needed. Charge battery from grid the rest of the time.

If you want to add PV, various AC and DC coupling options. Most AC coupled inverters are 240V, less convenient to use with this 120V inverter. A DC coupled SCC and battery shunt could be the way to go.