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Newbie Terms and Concepts

Cduck28z

New Member
Joined
Jul 29, 2022
Messages
26
tldr;
Are all off grid inverters capable of pulling power from the grid without sending power back to it? This should be useful for things like charging batteries and picking up the loads when your batteries are dead or the sun isn't shining?


Good evening,

I've brand new to the community, with a ton of ideas, and have been trying to learn as much as I can about all the different features and functionality of the many kinds of inverters on the market. I live in South Texas and my current electricity plan has free electricity from 8pm-6am every night. I would like to power my home from a battery bank with a bit of solar throughout the day, and recharge everything in the evening.

Here is where my newbie ideas and terminology really shine. I would like to create a semi-completely off grid system. Think of it like this: Install a sub panel for all my critical loads which covers 90%+ of my daily use (4ton air conditioning, kitchen, bedrooms, bathrooms, living room, and dining room), just like if you were to run it off of a generator when the grid goes down. The subpanel would be equiped with a Generator Interlock on the main breaker coupled to the generator input. This effectively creates a micro grid in my home and since the main breaker feeding the subpanel and the breaker being fed from the generator can never be connected at the same time.

Now replace the generator with a battery bank and inverter and BOOM, micro grid and free* energy. But here's the catch, I don't want to spend $15k to build a huge battery bank capable of running all day. I'm a hobbyist and would love to see a proof of concept and a working system before investing that much capital (and the wife REALLY doesn't like the idea of playing with numbers that big). So the big catch with the whole system is the *semi* part of semi-off grid. I need an inverter that can still provide AC power from the grid to pass through the device and power all of my energy needs when my batteries run out of juice before the end of the day. It also cannot be allowed to send any power back into the grid. And finally, it needs to be able to pull power from the grid in the evenings to recharge my batteries over night.

Is this a standard capability in the world of 'off grid inverters' or would this be considered a 'hybrid inverter'? Does anyone have any experience in building such a system? Sorry for the story time but it might be useful to explain my project and not just fish for some answers without any context.

THANKS!!
 
I'm on the same journey. In FL laws are screwed. Not legal to go off grid. Ins laws are such that going panels on the roof are not a good idea. You can't, going forward, insure a roof over 10 years old. Even if you install panels on a new roof, ya gotta take them down to replace the roof every ten years or forego insurance. not ideal So, renegade solar projects off-grid and off-roof is the way to go here. Good luck.
 
tldr;
Are all off grid inverters capable of pulling power from the grid without sending power back to it? This should be useful for things like charging batteries and picking up the loads when your batteries are dead or the sun isn't shining?


...
Some are and some are able to be set for zero export to grid while reducing grid loading. It is possible to do what you are thinking of doing the only question is loads and having an inverter rated high enough to run them. With that comes how to power the inverter.

Off grid hybrid AIO use 3 sources: Solar, utility and battery to create a AC output to your loads. In Utility mode they pass through your utility power up to the power rating for line and unit. If utlity is lost they switch to inverter powered by the battery (UPS) function). In solar mode they prefer solar power but switch to utilty if solar is insufficient. In Solar/Battery/Utility mode (SBU) the order is Solar then battery and finaly utilty.

They can charge battery either by solar, utility and both depending on how you configure it.
 
Off grid hybrid AIO use 3 sources: Solar, utility and battery to create a AC output to your loads......They can charge battery either by solar, utility and both depending on how you configure it.
So All In One (AIO) is what we're looking for then. I just put a meter on my 5 ton AC unit and it spiked to over 120+ amps. I'm hoping a soft-start unit will reduce this load to ~50amps but that's still quite the surge.

After spending quite some time shopping around, I'm looking at a couple options including the GroWatt SPF12000TDVM-MPV and Sigineer power M12048D. Both are 12kW inverters with a massive peak loading. I really like how they are 120/240 split phase which reduces complexity of the system and external wiring of a transformer. I was considering a pair of the EG4 6500 EX-48 wired together to make 240v but the AIO seems simpler?

Are there any other inverters or setups that anyone might recommend or is it time to pull the trigger start building?
 
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