Off grid experiences and regrets

Thought I would share some of my experiences and learnings with my quest to be independent of ESKOM.

First some stats of the system that i had installed.

2 x Chase Megarevo 8kva inverters

6 x Chase 6.1 Kwh lithium batteries

22 x Trina 550w solar panels

Things to consider in your off-grid journey in South Africa

1.       Inverter KW rating (minimum 12KW)

In sizing my system, I had to keep in mind the primary purpose was to go off grid or get as close to it as possible. My starting point was to replace the ESKOM single phase input which is 220V at a max of 63A giving a theoretical max from ESKOM of 13.8 KW so I wanted my inverters to be rated for at least that, so I decided that my choices were one 16KW or two 8KW inverters I decided for the parallel inverter setup for the redundancy and added flexibility in panel configuration that it offered. I have not been over the 63A usage often but I have, so this was a must for me.

2.       How many panels (As many as you can)

There are many calculators and opinions on how many solar panels you should install, and here is my take: Install as many as physically possible. I can’t tell you how many times I regret not getting panels installed on some of the less-than-optimal areas on my roof, Why? Well it seems that most of those opinions and calculators telling you how many panels to install are looking at average sunlight for your location, when going off grid average is not going to cut it, you want worst case, when it is overcast for 3 to 5 days in a row and you start shouting at people for using hot water and your wife is grumpy that the pool is green because you switched off the pool pump, and you looking at the solar app obsessively, when those overcast days roll around you will be glad you put those extra 10 panels in, the additional cost when you do it all at once is far less that calling your installer back to install a few more.

3.       Battery KWh (24 hours of usage)

These are the most component of the system and hard to get an idea of how much capacity to install, so I went with the following install enough battery to run your house for 24 hours or as close to that as you can afford, it follows from the solar panel logic that you are not sizing for the average day you are sizing for the worst case. In winter when there is less solar production, my batteries hardly ever go under 50% in summer it is almost never at 100% because of all the cloud about.

I consider the above the minimum for gong off grid, there are other things to consider when selecting the equipment, you will be using, and the many manufacturers out there offer a variety of features that will interest you, good luck with that choice.

Some things I regret,

550w panels instead of 720w the price difference is minimal,

Wrong soalrman dongle, the ones I got do not integrate to Solar assistant.

Not putting on more panels.

The batteries I got seem to only charge at 100A (could be a config issues that I need to look into)

A high voltage setup may have been better for my needs.

The firmware on the inverters is not very good

Some summary stats from solar assistant,

the grid usage by the inverters irritated me so I disconnected the inverters from the grid totally in October.

The house hold has 3 adults till May when it increased to 6.