Using a Grid Tied inverter off grid using the ac coupling abilities of the victron multiplus

[@Electronzap]

I think that makes sense. A grid tied inverter is just intended to turn off when the grid goes down so that it doesn't electrocute someone working on the grid. The grid tied inverter has no idea if the other power it senses comes from an alternator/generator or from the actual grid as far as I know. Instead of helping the grid, it's helping some other AC source.

[@livingoffgridinscotland]

Yes exactly

[@offgridwanabe]

I have been doing this for years, it works great as long as you don't exceed the load when your batteries are full unless your inverter can control the hertz from the grid tied inverter so keep your grid tied portion at 80% of your inverter rated max power. I would also run my generator through a separate inverter just for charging the battery when there is not enough sun.

[@camillitech1]

Great work Richard, big fan of AC coupling my self here been using it for years. However not so keen on the idea of using a lightweight inverter with no transformer to do it ;-) Your PV capacity should never exceed your inverters charging capacity. If using wind it should be double the output of your wind turbine ;-)

[@livingoffgridinscotland]

What inverter would you suggest? The Ginlong/solis was recommended by several people on Facebook…..

[@camillitech1]

@@livingoffgridinscotland the Ginlong is a great inverter. The founder of the company 'Ginlong Jimmy' was at uni in Edinburgh with a Pal of mine. I have done trials for Powerspout using one of their inverters and several others. First class product and 'back in the day' a very approachable company. However for AC coupling I would always use a low frequency inverter like a Victron, Outback, Studer or SMA. Probably not so crucial with solar only applications but I'd be very dubious about AC coupling wind or hydro with one. Good luck, for applications like yours or mine (large with lots of inputs over several buildings) AC coupling rules ;-)

[@HotNoob]

nice. i'm going to be doing something similar this summer. i have 2 locations, 2 solar setups and want to make my own "off the grid" "grid". my concern is tho; i thought the grid tie inverters will only output to the grid if there is voltage on it... but i could just have to find a setting for that or something.

[@livingoffgridinscotland]

Victron and older outback inverter act as the grid, so then the grid tied inverter outputs power at 1volt higher than the victron output and slightly higher frequency

[@Self.reliant]

The only thing I can see as a problem is that the main inverter doesn't know how much AC wattage is coming in so it won't know to maximize the charge. I'm interested to see how you are over coming this

[@jasontaverner2634]

"make your own grid" = use the AC out of an inverter to provide "mains" power. Its called creating a micro grid. "AC coupled" = solar controller outputs AC instead of DC to use with Victron in an off grid scenario, the grid tie inverter needs to respond to changes in the frequency so that the grid tie inverter backs off power in case the batteries are full. Otherwise you can overcharge your batteries.

[@livingoffgridinscotland]

Just to confirm, a dump load is also connected to the batteries as a fail safe through a tri star charge controller

[@GregOnSummit]

Interesting ... if the panels producing power to the grid-tie stop because of night time, and stop sending power to the Multi, how does it recognize that there is a fake grid on start up? Are you running on batteries to the Multi to create the AC that the grid -tie needs to start up?

[@livingoffgridinscotland]

Yes we are off grid so we have batteries

[@s.r.8471]

Awesome 👍

[@livingoffgridinscotland]

Thank you! Cheers!

[@contemporiser]

I have Shneider XWpro and I plan to do exactly what you did here. I'm sure it can do it. I am only concerned what will happen if I have full solar production, batteries at 100% and just a few watts of consumption.

[@livingoffgridinscotland]

You need to set up either a dump load or diversion load to divert the excess power to heaters or hot water

[@bad191000]

I've never done this before. Can someone explain how this would be more beneficial than just taking AC power straight from the victrons?

[@livingoffgridinscotland]

I’m sure I explained this in the video? Only 5% losses using ac coupling, it’s 30% losses going into the batteries and back out, it also allows us to use diversion via pwm controllers so excess power can be used for heating and hot water via dump loads using a relay driver

[@briansmall_ca]

Interesting!

[@livingoffgridinscotland]

Thanks!

[@scott5747]

Aren't you suppose to use concrete backer board and not plywood or drywall for mounting hardware?

[@livingoffgridinscotland]

I can’t find anything in the 18th edition regs regarding this….. My other system is on 1mm galvanized steel sheet

[@ivanleow1]

Hi may I know which Victron multiplus inverter did you use for this setup.

[@livingoffgridinscotland]

You can use any multiplus, provided the charging capacity is higher than the pv output

[@MTHomestead]

It is like you are talking to me, because I do not know what I am doing when it comes to this. Is there a Solar Power Class 101 professor before I jump into this 202 class, just kidding but I want to know more about this stuff.

[@earthenergyhex]

I see you have grid out there. LOL just kidding

[@mattsaulsbury1831]

i thought this was possible. basically just loop it around and fool the other one, and use it to feed each other??.......

[@mattsaulsbury1831]

everyone kept telling me u can't use one to create a grid and another one to feed it.

[@livingoffgridinscotland]

@@mattsaulsbury1831 the victron multiplus or Quattro is an inverter charger and creates a “mini grid” the grid tied inverter senses this as the grid and powers up, feeds power to the grid constantly, the victron uses surplus power that isn’t used to charge the batteries, you do need dump or diversion loads in the event that batteries are full and you arnt using all the power the panels are using

[@johndalton183]

You lose more energy going from 500vdc to 230vac and into the other shed and then a battery charger than using 4mm PV cable to take the dc to the other shed. So efficiency wise you’re doing the wrong thing.

[@briansmall_ca]

I was thinking about this as well.

[@livingoffgridinscotland]

@@briansmall_ca not really, the point is this inverter overrides the victron so the power will be used first and only the excess will be charged into the batteries. We also have standard charge controllers, it’s part of a bigger system, you get 30% losses going panels-charge controller-batteries-inverter, this system you get approximately 5% losses

[@briansmall_ca]

@@livingoffgridinscotland Interesting. I’ll go back through your videos to get a better sense of your system. I’m not looking just to be critical 😉. I am in the process of developing an acreage in the middle of nowhere Saskatchewan. It’s currently grid connected but solar is on the todo list. By training, and occasionally by profession, I’m an industrial control systems technologist but I have little experience with solar.

[@livingoffgridinscotland]

It’s very much a case of “horses for courses” I’m seeing most of the proper off grid guys over here using a combination of standard off grid kit and these modern grid tied inverters then running their big loads when they have lots of power coming in, so setting timers for electric heating, hot water etc to take advantage of the power when it’s available to save storing it in batteries….