Solar PV Hints, Tips & Troubleshooting

You'd need to check the specification of your inverter and panels to determine how many panels may be connected. but as bullit said 12 or 13 is typical. German division of my inverter manufacturer has an excel sheet to calculate all this easily and for instance with my panels 12 is max but another manufacturers panels the max is 7 per string!

If you only have 10 on one string you could add a second string (assuming you have two MPPT). Note like the max per string there is also a minimum per string as well.

The inverter is a Solis-mini-3000-4G. 10no. 320w currently fitted.

Your going to struggle there with your inverter. What you can do is upgrade your panels by adding 7-8 more into your existing 3.3kw inverter. Even though you will have 5Kw+ in panels, you inverter will only pull down 3.3Kw.

In some respects, you will be "wasting" generation, but what it will mean for you, is that you will hit your "max production" threshold on more days of the year. If for example say you were generating 2-3Kwhr off your existing panels for some day in Feb. Then increasing your panel capacity would raise that generation to 3-4Kwhr. However come summer time.....when the sun is shining you'll be wasting your panels output by your inverter cap.

It's a tough one to call. I think long term, if you are thinging of powering your EV and adding a 2nd one, coupled to the rising price of electricity/gas (Ukraine notwithstanding) replacing your existing system with a higher capacity one is the way to go. Keep your existing panels, but add a new array of new panels to a new hybrid inverter rated 5Kw (ideally 6Kw)

my bad, was taking this image as two strings

It was on your advice I went for the 6kw inverter for my install and really glad I did so thanks for that. What batteries are you running in your system?

Good luck with that 👍👍

Does it "really" matter though? 5kw verses 3Kw? I ask not knowing your situation.

My thinking on this is more around the fact that you have a certain energy in your battery. That battery will last a certain time limit. If it's empty at 7pm and you've been importing 2Kw from the grid cause the battery couldn't give everything......or the battery is empty at 6Pm cause it could give everything.......you're just moving the timeline of what your importing. In either case it's given out all that it has stored into your house. No?

I should say that with the high usage that I have, there hasn't been one single day that my battery (8.2Kwhr) has gotten me to night rate......so I might be a little unusual here.

We both work from home for most of the week. For the mileage we are doing we are saving 30-40 euros a week with the one ev. Going with a second ev would yield a similar saving but countered by having to pay additional charging at the night rate to make sure both cars are sufficiently charged. With longer days ahead maximising the yield from the inverter that we have seems the most sensible option.

That is pretty great TBH. You mentioned tweats... anything you can share? Was it on the Solis Inverter side of the house or the battery side that you tweaked?

I suspect - with a 4.8Kw Dyness battery - i cant get to 5Kw unless I add a second 4.8Kw Dynness battery - im only getting 2.5Kw now - but i think thats correct for my setup (my inverter is 6Kw and 5g)

That doesn't sound right unless the battery only has 0.5C and not 1C charge/discharge.

Seems like a waste not having 100a charge/discharge on a 5kwh battery. You sure the charge/discharge settings are correct on the inverter? The inverter can do 100a for sure. Check the spec sheet of the battery and see if it's only 50a

I logged a call after the install with Solis and they told me I was running the latest code.

I've recently had a system installed, with a 6kw Solis Hybrid 5G inverter, 5kwh Puredrive battery and an EDDI. 

In general, I'm very happy with it. There are few things I'm trying to get a greater understanding of.

During non-daylight hours, when the PV is no longer producing, I see a mismatch between the power the battery is delivering compared to what the house is consuming.

I realise that the battery side is possibly measured in DC @ 50v, and that there are going to be conversion losses. But, the difference exceeds what I'd expect.

The Solis Home app shows the readings, and I'm also verifying the same by querying the inverter/datalogger directly with a python script (pysolarman, thanks all in the monitoring/automation thread).

Per this screenshot, you can see that battery is delivering 480w, and the house is consuming 330w. A this point in time, there is no grid import (but that can flip to 40 or 70W, depending on when I look)

So, there is a delta of 150w. And there is always a delta of somewhere between 120 and 180w.

While 150w is not a huge amount, it does add up. 

150w over 6 hours (i.e. 5pm to 11pm) is 900wh. Which equates to 18% of my battery drained from sunset to night rate.

The 330w house load is accurate: to verify I've switched off most mcbs, and put a power monitor socket the remaining appliances.

Are others seeing this?

And what is the reason of a mismatch? (I can accept 10/15% conversion losses, but this is always greater)

If you look at the previous days data does it show all that wasted power ?

Just wondering is it a timing thing.