Finally - My solar PV installation

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semipro

Minister of Fire
Jan 12, 2009
4,027
SW Virginia
I finally installed the batteries but not what I'd originally planned. I ended up buying about 20 kWh of LFP plug-and-play batteries from BigBattery. I toyed with the idea of used former EV batteries for backup but fear burning down the house and feel that LFPs are safer. One 200 watt panel is backed up, the other not. I rearranged all the wiring and loads accordingly.
Solar inverter and batteries.jpg carport looking north.jpg carport with metal roof.png panels.jpg Gutter.jpg EVSE.jpg
 
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SpaceBus

Minister of Fire
Nov 18, 2018
5,948
Downeast Maine
Wow, that's pretty amazing! At least they offer a discount for multiple battery packs. I'm hoping by the time we are ready to move forward with solar the cost of storage will come down.
 

semipro

Minister of Fire
Jan 12, 2009
4,027
SW Virginia
I've been thinking that I can add extra capacity to my system by adding a 6th row of panels along the bottom after extending the rails. However, this would overload my 8kw inverter so I was thinking I could use microinverters with the added panels and tie those into the 50 amp circuit for the vehicle charging station shown in the last photo.

I'm thinking that even during an outage the microinverters would sense my central inverter-driven microgrid, think that the "grid" is up, and continue to produce power.

Am I thinking about that wrong? Anything else I might be missing?
 

semipro

Minister of Fire
Jan 12, 2009
4,027
SW Virginia
Wow, that's pretty amazing! At least they offer a discount for multiple battery packs. I'm hoping by the time we are ready to move forward with solar the cost of storage will come down.
Prices for a decent battery that you can install without a lot of work or know-how are really dropping. One of David Poz's latest videos shows a good example.
 

peakbagger

Minister of Fire
Jul 11, 2008
6,350
Northern NH
I've been thinking that I can add extra capacity to my system by adding a 6th row of panels along the bottom after extending the rails. However, this would overload my 8kw inverter so I was thinking I could use microinverters with the added panels and tie those into the 50 amp circuit for the vehicle charging station shown in the last photo.

I'm thinking that even during an outage the microinverters would sense my central inverter-driven microgrid, think that the "grid" is up, and continue to produce power.

Am I thinking about that wrong? Anything else I might be missing?
My 660 watt array uses microinverters, except my 4 panels are home run to my basement and my microinverters sort of look like a blade server installation. I think your proposed use of microinverters "should sync" to the microgrid you have built as long as the house is continuously pulling more load than the microinverters can use. In theory the microinverters just offset the house load and the hybrid inverter just shunts more load to the battery. The devil is what happens if the micros are generating more than the house is using?. My guess is without enough load the voltage goes over the 1741 inverter setpoint and the micros drop off until the micro goes through the 5 minute wait time and then repeats. I seriously doubt the hybrid inverter will run backwards to take 240 VAC from the micros and charge the battery with power from the micros. Then again you may see the expensive puff of smoke from the inverter ;) but I expect not as I expect it would have AC input overvoltage protection (check the spec sheet).

An interesting but potentially expensive experiment. If you have a spare panel, used enphase micros are cheap so you may want to experiment with one.

I will need to check out your battery source, maybe they can supply a battery to replace the Tesla high voltage battery that my hybrid inverter needs
 
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semipro

Minister of Fire
Jan 12, 2009
4,027
SW Virginia
If you have spare panel, used enphase micros are cheap so you may want to experiment with one.
I was thinking the same. I have a spare panel and have been looking at microinverters.

The devil is what happens if the micros are generating more than the house is using?. My guess is without enough load the voltage goes over the 1741 inverter setpoint and the micros drop off until the micro goes through the 5 minute wait time and then repeats. I seriously doubt the hybrid inverter will run backwards to take 240 VAC from the micros and charge the battery with power from the micros. Then again you may see the expensive puff of smoke from the inverter ;) but I expect not as I expect it would have AC input overvoltage protection (check the spec sheet.
I had assumed that microinverters would just cut back production once demand was met so it sounds like I should look into that in more detail to protect my inverter.
 

peakbagger

Minister of Fire
Jul 11, 2008
6,350
Northern NH
BTW in addition to the micro you need a trunk cable for it to plug into. There is usually someone on Ebay selling used trunk cable.
 
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semipro

Minister of Fire
Jan 12, 2009
4,027
SW Virginia
BTW in addition to the micro you need a trunk cable for it to plug into. There is usually someone on Ebay selling used trunk cable.
Thanks. The cables seem to be a gotcha as far as cost. I've been looking on Ebay for used units with cabling.
 

semipro

Minister of Fire
Jan 12, 2009
4,027
SW Virginia
The devil is what happens if the micros are generating more than the house is using?. My guess is without enough load the voltage goes over the 1741 inverter setpoint and the micros drop off until the micro goes through the 5 minute wait time and then repeats. I seriously doubt the hybrid inverter will run backwards to take 240 VAC from the micros and charge the battery with power from the micros. Then again you may see the expensive puff of smoke from the inverter ;) but I expect not as I expect it would have AC input overvoltage protection (check the spec sheet).
I had assumed that microinverters would just cut back production once demand was met so it sounds like I should look into that in more detail to protect my inverter.
I found out that my hybrid inverter is smart enough to shift the frequency of the microgrid it creates out of specs so that any AC coupled grid-tied inverter/microinverters will shut down to maintain a net zero balance of microgrid power (input versus output).
 
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