Need help with Grid interactive/Hybrid inverters,

[Logan005]

We are having our 1k watt solar off grid backup system upgraded with another 5k watt's of solar. Our installer wants to install 16 Micro-inverters, but we want to have power during and after storms. before he installs, I need to know what inverter I can have him install that is similar price to the 16 micro inverters. that will allow me to expand as we go along. We currently have 8XT-105's but will likely upgrade to 4 or 6 salt stack 48 volt batteries in the future. We have a large home but is mostly Nat Gas for cooking and hot water. Led light's throughout. We would unlikely need Air conditioning after a hurricane, Sometimes we even need heat, but we have Nat Gas for that.
I would love a Radian, but it need to be similar price for the contract we already have with the company.

Thanks in advance Jim...

[Mike90250]

Hold yer horses !
Mixing micro-inverters with an off grid inverter will be problematic. When the battery fills up, how do you tell the micros to stop ?

Some brands (sunnyboy) can shift the AC frequency to knock micros offline, to limit charging, but this needs to be well planned, or you will have a mess.

Pricewise, there is not a lot to choose from.

[inetdog]

I think you meant to refer to the SunnyIsland, the off-grid inverter, not the SunnyBoy.
One useful feature of the SB is that the grid tie inverter output can be proportionally controlled by the SI through frequency shift rather than just having an all-on or all-off choice.

[Logan005]

. Thanks, Jim...

[ButchDeal]

If you read OP, notice, I have a DC system, no inverter. I am having installed grid interactive system. Installer wants to install micro inverters. I want central islandable Hybrid inverter info. No mention of mixing inverters. Rather making the right choice now so system will be scalable for future upgrades. I am considering the Sunny Island, Just need to know enough to get my installer through it, since he has only done micro inverter installations. Thanks, Jim...

Yes the micros would be grid tie and the Sunny Island would be battery. Thus the mixing that he was talking about.
I would also suggest skipping the micros altogether and going with OutBack, a much more focused bimodal brand than the add on Sunny island.
I would suggest also that you find another installer. One ONLY familiar with Micros is pretty limited in experience to be tossing into the deep end with strings and bimodal.

[Logan005]

Yes I also like the Outback product line, we already have a Flex80 for the existing panels and batteries Yes again, as I said in original post I do not want the micro inverters our installer has been offering. I am just getting info, so I know what to tell them that I do want. We already have a contract. I will look further into the Outback radian systems, but sunny island seems like it will do everything I need it to do. I just want to make sure everything is done correctly and in our best long term interest. Thanks Jim..

[Logan005]

So are the only options SMA sunny Island and the Outback/Schneider radian. what about the mains auto cutoff? I have 2 panels one outside and a sub inside. I only plan to energize inside panel during power outages. and eliminate unnecessary heavy loads for long outages.

[inetdog]

So are the only options SMA sunny Island and the Outback/Schneider radian. what about the mains auto cutoff? I have 2 panels one outside and a sub inside. I only plan to energize inside panel during power outages. and eliminate unnecessary heavy loads for long outages.

In general hybrid inverters contain their own transfer switch to cut off the grid connection when the inverter is supplying power in standalone mode, in the absence of grid power.
So you would wire a grid input to the hybrid inverter and connect the inverter output only to the inside panel which is supplying your critical loads.
If you need to also disconnect some of the loads on that same panel then you would have to install some sort of separate load shedding device and drive it with something that sensed the presence of grid voltage.

[Logan005]

since both panels contain heavy loads, should I consider a sub panel for critical loads to pre isolate them for outages?

[inetdog]

since both panels contain heavy loads, should I consider a sub panel for critical loads to pre isolate them for outages?

That would certainly be the simplest way to handle it, yes.

[ButchDeal]

So are the only options SMA sunny Island and the Outback/Schneider radian. what about the mains auto cutoff? I have 2 panels one outside and a sub inside. I only plan to energize inside panel during power outages. and eliminate unnecessary heavy loads for long outages.

Outback makes the Radian and what I would recommend for your size would be the Outback Flexpower 1 which is about 3kw with auto transformer if you need 240V (PSX-24). Schneider makes xantrex systems and they are similar.

http://outbackpower.com/outback-products/integrated-systems

The bimodal system would connect between two breaker panels like you have them and disconnect from the outside one on grid outages. keeping the inside one running on solar/battery.

I think you mentioned that you already have a FlexMax CC so the outback would integrate well with that and control it. The Flexpower 1 would come with another FlexMax CC as well for the new PV modules.

[Logan005]

Very well, I am prepared for that and seems most logical for the circumstances. this would simplify everything and allow seamless operation as desired. so the SMA sunny island should compare in price to the 16 micro inverters? or am I going to have to pay a lil more? I can get an electrician to create a sub for critical loads, should it be a problem if the batteries are located 20 feet across the garage? I would locate the inverter directly at the battries and run the feed to the Critical load panel.

[sensij]

The Sunny Island will manage the battery and grid connection, but you'll need a Sunny Boy inverter along with it to manage the array. There is no hybrid solution comparable in price to the micros.

[ButchDeal]

Very well, I am prepared for that and seems most logical for the circumstances. this would simplify everything and allow seamless operation as desired. so the SMA sunny island should compare in price to the 16 micro inverters? or am I going to have to pay a lil more? I can get an electrician to create a sub for critical loads, should it be a problem if the batteries are located 20 feet across the garage? I would locate the inverter directly at the battries and run the feed to the Critical load panel.

put the inverter next to the batteries. Make sure you have the batteries in a battery box vented to outside.
The Sunboy/Sunny Island is not going to be cheaper than micros.
OutBack Flexpower one will likely run you around $3k and will integrate well with existing FlexMax.

[Logan005]

put the inverter next to the batteries. Make sure you have the batteries in a battery box vented to outside.
The Sunboy/Sunny Island is not going to be cheaper than micros.
OutBack Flexpower one will likely run you around $3k and will integrate well with existing FlexMax.

Thank You! Butch, this is exactly what I was looking for. Let me research and digest and further questions. Jim..