AC Coupled Enphase Micro Inverters & Lead Acid Batteries – Whole home UPS

skidew42

New Member
Joined
Dec 5, 2021
Messages
2
The ask: Can I use the Enphase Smart Switch with a Non-Enphase inverter/charger? What are some options that might work together? If not, what other options exist?

I have a grid tied 10.4kw Enphase solar system and 16kw of batteries that I want to combine in a way that would allow the solar panels to produce if the sun were up and the grid were down. I have the IQ7A micro inverters and an Enphase Envoy in a combiner box right now. I was looking to add the Enphase Smart Switch (for grid-agnostic) but it appears it would require the Enphase Encharge battery system. I already have 16kw of lead-acid batteries I can use if I can figure out how to charge/invert them to feed the Smart Switch. I am open to looking at other options to provide the grid agnostic capability. If there a different option that I should be looking into please suggest it. The goal is to use the grid if it is there and have solar and/or battery backup when the grid is down.

The Enphase Smart Switch provides the automatic transfer switch function as the grid comes and goes. Additionally it has a generator hookup that is appealing as it would allow for a longer grid down outage and allows for emergency power. In theory the system should act like a whole home UPS with generator backup. I understand the solution using batteries and solar only works for a short outage and augmenting the power from another source like a generator would be required for extended grid-down coverage.
 

Ampster

Renewable Energy Hobbyist
Joined
May 3, 2020
Messages
4,648
Location
Kenwood, California
I already have 16kw of lead-acid batteries I can use if I can figure out how to charge/invert them to feed the Smart Switch.
Do you mean 10kWh?
I agree that the Enphase Smart Switch would probably only work with the Enphase battery. A switch without a battery powered inverter is not going to enable AC coupling the micros anyway. The only solution, that is obvious to me, is a hybrid inverter which contains a transfer switch.
 

newbostonconst

Solar Addict
Joined
Sep 24, 2019
Messages
663
Just use a "hybrid inverter" with "ac coupling" and a "critical loads panel". Search those key words if you have questions.....It am guessing it will be cheaper.
 

skidew42

New Member
Joined
Dec 5, 2021
Messages
2
I appreciate the replies. Can someone provide specific suggestions for hybrid inverters or other options that may work? My initial research is showing that it would be cost prohibitive and it would be better to spend a couple thousand more on a new Encharge 10 and Smart Switch. For about $9000 I can have that solution in place but then I have 16kwh of batteries that are useless. They didn’t cost me anything but it’s just a waste.
 

newbostonconst

Solar Addict
Joined
Sep 24, 2019
Messages
663
It depends on your capabilities...
Like the Outback Radian 8k will AC couple for $4500 without the load center...$600 more with the load center....$0.56 per watt
Outback Skybox 5k will AC couple for $3600 .....$0.72 per watt
Sol Ark 8k will AC couple for $6100.....$0.76 per watt

The Radian is what I have and is the cheapest but takes the most setup as far as I know.

Those are the inverters that I know of that have been successfully set up to AC couple that I know of and are UL listed.
 
Top