suggestions for adding grid tie to existing Off grid system

Only need to change inverters if you intend to sell power.
The plus I see is it could increase your property value having utility.
The minus is the expense to connect and possible building department/utility requirements.

If you are running a genset for air-conditioning you really should look into mini-splits. I have over 100 offgrid clients doing that. Many do not even need a genset depending where they live. I am happy to be one of them

For a split to work well and cool the whole house offgrid, it needs to be the best model available.
 If you look at LG, Panasonic, Fugitsu or mitsu, they all have 3 or more models in the 12,000 btu range. The most expensive is what you want. It will have SEER ratings of 25+. Many use the 9,000 btu models offgrid and they can easily get over 30 Seer. You need to run a split from 220 vac to get these numbers.

An array that faces south east to start the cooling early and a south west array to run late when cooling. They run all the time when you need it and can use as little 300 watts at night keeping the place at 77 or so. 

We were at 100f alot with wildfire smoke and had no problem running 24/7 for a month.  It seemed like a year. Man did this year suck or what? Can't wait until New Years to kiss it goodbye

I would lose the 24v inverter, go 48vdc with the Schneider CSW 4048 or the small Outback Radian. Your batteries will be much happier. Good Luck! 

denlow1 said:

Thanks for your insight. I am not real concerned with selling power as we are just "squeaking by" as is. 

It's a good time to remember that off grid systems have much more losses than the grid. Because you must reach full charge and lose all the 'extra wattage' several times a week.  Array's for the same amount of energy used will be more than 2x the size for the same energy used. I would encourage you to 'bank your energy' with the grid and use the batteries as backup. Do a full cycle, every month for battery health. Bring down to 50-60% and recharge.

If you can do this without allowing your energy use to grow too much, you should be better off with your energy budget, on a grid tied system. Your FLA batteries 'suck energy' with losses, as well as your inverter changing DC to AC. If you have both the grid and a battery system you will save a minimum of 25% wattage drawing from the grid rather than the battery system BEFORE considering the energy lost when you reach absorb and later float.

I'd be glad for others to jump in if they feel I'm wrong, I've lived off grid only, have huge losses as I sized my system to run air conditioning. I don't own a generator.

denlow1 said:

Trace PS2524 invertor with generator control module and  remote controller

8 L16 RE batteries (24 volt: 2 parallel strings of 4 ea)

Nice to see you are currently running 2 parallel strings of batteries for your 24 volt system. It will be a great time to replace your 24 volt inverter with a 48 volt one. Wish I could address hybrid inverters, but no experience with them.