Converting 50kW system from micro inverters to 8x SMA inverters

[Ampster]

........We had a power outage that lasted from around noon until 4pm. I made a note to myself that if we get another power outage like that when its really cold outside, I'll turn off the DC disconnects on the SBs. That said, when the grid is down, nothing it being "inverted" to AC, so I don't know if that means the SBs would be ok if the DC input went above 600V?

That is probably a safe strategy in cold weather. I do not know the internal electronics of the SB's but high voltage could damage the MPPT section of the device even if the inverter is not running and no current is flowing.

[pclausen]

Yesterday afternoon I got pretty close to the 600V DC input limit the SBs with 16 panels in series per string:



13 Volts to spare. We had a power outage that lasted from around noon until 4pm. I made a note to myself that if we get another power outage like that when its really cold outside, I'll turn off the DC disconnects on the SBs. That said, when the grid is down, nothing it being "inverted" to AC, so I don't know if that means the SBs would be ok if the DC input went above 600V?

[pclausen]

Got a new toy:







Man, that 225A breaker sure gets hot with 200+ Amps passing through it. So does the 300 MCM copper table.

Its not quite as bad on the other end of the 300 MCM where it terminates at the meter base:

[oregon_phil]

Thanks for the very complete build history and Home Assistant screen shots. I have HA, but have nowhere near your level of devices. I only have one SMA inverter and I don't mine, however. That makes it much easier for me to display data.

[pclausen]

I had the devs that do the SMA integration for HA add the Isolation Resistance sensor to their integration and I was able to incorporate that into my solar dashboard:



Since the default threshold is 500 kOhm, and the max reading is 3 MOhm, I set the threshold to 16% (where the red turns green).

I'll probably do a time graph as well to track how the value changes for each inverter during the day, but this will do for now.

August was pretty cloudy this year, but I did manage to break 350 kWh a day once: (I had to restore from backup on 8/8, so I lost a day of data)



So I'm easily producing more power that I consume for my mining operation this time of year: (I had an issue mid week with the BrulTech GEM collecting power consumption from the mining rigs, normally they are all at around 200 kWh daily)



I'm overall very pleased with the conversion from micro inverters to string inverters so far and it feels good to know that all panels are operational.

[pclausen]

Yeah I'm aware. That's basically my mining rigs and servers that run 24/7. I just put together a "Mining" dashboard a few hours ago, so it had not yet had a chance to accumulate much for kWh for the mining rigs yet, but you can see the live Watts are about 10kW:



I got the shop panels cleaned last night:



Every little bit helps, lol.

[SunEagle]

I don't know if you noticed but you used 10kWh each hour for a number of hours in the morning. That amount would drain a standard Tesla battery system.

[peakbagger]

Definitely looks slick !

[pclausen]

Finally got my Energy dashboard in Home Assistant properly configured:



Pretty slick I think.

[pclausen]

Good idea about even and odd lots. Will definitely give that some thought.

Finally had the sun peek out today:



The shop roof inverters finally got a bit of a workout. Still can't wait for a nice clear, cloud free day, from sunrise to sunset.

[GoingElectric]

GoingElectric ... and 2 daughters, so yeah, I use a lot of power.

Yeah, that would do it.
(shudder to think what bill was like before)

VERY nice work, thanks for sharing your experience!

On the micro sale, maybe a lot of ODD and EVEN, perhaps 3 and 4, people can buy a few lots to get the number they need (thought)

[pclausen]

Hot and hazy today with a thin layer of clouds, but I did manage to break 45 kW:



Trying to figure out how to best sell all those micro inverters and cables. I'm thinking trying to sell them in packs of 12. All tested of course, with cables and end run connectors. They will be plug and play into a 20A breaker. They still have 5 years of warranty left on them.

[pclausen]

GoingElectric My solar augments my crypto miners and the house is pretty big and I got a pool and servers and stuff like that. Also have an in-law suite in part of the basement where my mother-in-law lives and wife and 2 daughters, so yeah, I use a lot of power.

I finally got everything done yesterday afternoon. It was pretty grueling with temps in the 90s and high humidity. I had to take frequent breaks, jump in the pool and what not. After that experience, I really feel for people that install solar panels in the summer, especially in the Southern states. Back in 2016 when I initially installed the panel on the shop roof, I was in September, so much cooler temps.

nerdralph Those fittings you linked to worked out perfectly. I used a 9 wire one on the roof and it matched the 1 1/4" threads on the EMT elbow perfectly:





I tied the wires up nicely before dropping the last panel over top of it.

All 8 inverters wired with #6 L1/L2:



Wire ways ended up pretty well stuffed in some sections:



I bundled the AC wires separately from the DC wires:



All closed up:



I literally had a mountain of cables left over from removing the micro inverters:



Power output @ 9:30 am this morning:



Home Assistant Energy readout at the that same time:



I only just configured it yesterday, so I'm still tweaking.

Also still working on adding all my devices. Here are the ones I added yesterday and this is their consumption so far today (as of 9:30 am):



I have a total of 96 channels with CTs on them that I need to add and that still doesn't quite catch all the circuits I have between the 2 main 200A subpanels, the shop 200A subpanel, the server room 100A subpanel and the garage 100A subpanel.

Even with the 50 kW solar plant, my electric bill is still about $300 in the summer and higher than that in the winter.



But now that all the panels are producing all the time, and my efficiency should be better, I'm very curious to see what my next few bills are going to look like. I'm also going to wash all the shop roof panels as most of them were pretty nasty looking.

[GoingElectric]

pclausen May I ask what you do with 50kW of power?

[pclausen]

I hear on not walking on the roof until it is completely dry. Challenge is that by then it is hot as hell. My Dockers sandals seems to stick pretty well to the metal roof, even if wet. But yeah, I hear you. Its about a 12ft drop from the lower edge of the roof to the ground. Would probably hurt plenty.