diy solar

diy solar

Greetings from Denver CO

Lost_One

New Member
Joined
May 13, 2022
Messages
38
First off this is a great community and I look forward to contributing to. I have been lurking around for sometime with my ambitions to 1) expand my current system and 2) offer some some sort of power backup in the event of a power loss, or deliver power from batteries to offset peak rates as the sun goes down( if this is even possible ).

I currently have a 4.5 kW grid-tie system with Enphase 215s. This produces about half my annual power.

So I am hoping that I can add additional panels and have a battery back up for essentials, but also be able to use the power produced by the new panels. Q: Based on what I have been reading, would this be an off-grid system with a DC-coupler? Can I use this in addition with my Enphase system?

Now, let take a scenario where we have an extended power loss, I would like to have power from the new system, ( I am pretty sure that my old Enphase system will not work without grid ) to keep the critical devices up? Are my thoughts on the right track?

Finally, being that I have been out of the loop for a while, what are some good recommendations? For the new addition, I am aiming towards 1.5 kW with 6 ground mounted panels. Where I get lost is looking at the different electronics. I am used to seeing Outback, SMA etc, but seeing these new all-in-ones seem too good to be true /reliable. I look forward to your thoughts and being able to focus in the right direction. I like the idea to where I can DYI a battery bank, but am open to pre-made solutions.

Regards,

JC
 
Since you already have the Enphase Grid-Tie system its very common (and the easiest way) to go with an AC coupled battery inverter. Interestingly one of the main complaints with the Schneider Conext Pro is that it doesn't have a built in MPPT charge controller but for AC coupling you don't need it thus you are not paying for unnecessary hardware. Otherwise the Schneider checks off most of the other boxes. I'm using the older model Schneider XW+ for whole house back up in an AC coupled configuration with a 3KW Enphase M250 system AND an older 2.8KW Solar City traditional string system on a Fronius Inverter. It all works together quite well.
Lastly, one down side of the Schneider in AC Coupled operation is the lack of options to trigger a bulk recharge cycle, especially when using the Peak Load Shave feature.
 
Welcome to the forum, I'm located in Colorado Springs, if anything I can do to help locally just pm me.
 
Since you already have the Enphase Grid-Tie system its very common (and the easiest way) to go with an AC coupled battery inverter. Interestingly one of the main complaints with the Schneider Conext Pro is that it doesn't have a built in MPPT charge controller but for AC coupling you don't need it thus you are not paying for unnecessary hardware. Otherwise the Schneider checks off most of the other boxes. I'm using the older model Schneider XW+ for whole house back up in an AC coupled configuration with a 3KW Enphase M250 system AND an older 2.8KW Solar City traditional string system on a Fronius Inverter. It all works together quite well.
Lastly, one down side of the Schneider in AC Coupled operation is the lack of options to trigger a bulk recharge cycle, especially when using the Peak Load Shave feature.

Thank you for the input. I have checked out these Schneider Conext as they seemed to be a great way to add batteries to my existing system. Question is, if I had an off grid solution as well, to add additional power as well as have a bit of juice when the grid is down, will that all still integrate, correct? I would need to have: Additional Panels --> MPPT CC --> Battery Bank --> Conext Pro -- main circuit panel and critical load panels. Then I assume that if the grid goes down, then only the critical loads is active? ( Gotta keep the linepeople safe )
 
Question is, if I had an off grid solution as well, to add additional power as well as have a bit of juice when the grid is down, will that all still integrate, correct?
You certainly could add some extra solar panels and a charge controller, I would recommend a Schneider because it is fully compatible with the Xanbus network. You would then have a combination AC & DC coupled system.
Then I assume that if the grid goes down, then only the critical loads is active? ( Gotta keep the linepeople safe )
UL1741SA compliant grid interactive inverters have a built-in disconnect switch that opens when the grid is down so there is no back-feeding into the AC Input terminals. Although if it were possible to move your Enphase breaker into the critical loads panel then the micro-inverters will continue to function supplying critical loads and charging the batteries via the internal charger in the Schneider Inverter. The problem with this arrangement is the battery charger cannot regulate the excess microinverter power thus will increase frequency forcing the Enphase microinverters to shut down at 60.5Hz when the battery voltage reaches the limit you have set. The older M215 models don't have output modulation so they are either ON or OFF. What tends to happen is the batt voltage reaches the limit, frequency shifts to 60.5Hz, grid-tie inverters shut off then 100% of the critical loads are supplied by the batteries which lowers the battery voltage which causes the Schneider frequency to shift back to 60.0Hz and the grid-tie inverters start up, complete their 5 min timeout and start producing power. Then the cycle repeats. I'm not sure if this puts extra stress on the system or not. The inverters cycle on and off every day anyway, not sure that being turned on and off a few extra times during an outage would really be an issue.
 
move your Enphase breaker into the critical loads panel then the micro-inverters will continue to function supplying critical loads and charging the batteries via the internal charger in the Schneider Inverter.
Interesting point. I will dig into this a bit more as there may be additional power that I did not think that I may have during a power event. Thank you.
 
Back
Top