Our 5.94kW solar array with Redflow ZCell battery and Victron Energy inverter/charger system is now slightly over three years old, which means it’s time to review its third year of operation. There are several previous posts in this series:

• Go With The Flow (what all the pieces are, what they do, some teething problems)
• Hack Week 21: Keeping the Battery Full (an experiment in working around the limitations of a single ZCell)
• TANSTAAFL (review/analysis of the first year of operation, 2021-2022)
• Still Going With The Flow (review/analysis of the second year of operation, 2022-2023)

If you’ve read the above you’ll know that the solar array was originally installed back in 2017 along with a Sanden heat pump hot water service. That initial installation saved us a lot on our electricity bills, but it wasn’t until we got the ZCell and the Victron gear that we were able to really manage our own power. The ZCell allows us to store our own locally generated electricity for later use, and the Victron kit manages everything and gives us a whole lot of fascinating data to look at via the VRM portal.

There were some kinks in the first two years. We missed out on three weeks of prime solar PV generation from January 20 – February 11 in 2022 due to having to replace the MPPT solar charge controller. We also had no solar PV generation from February 17 – March 9 in 2023 on account of having our old tile roof replaced with colorbond steel. In my last post on this topic I wrote:

In both cases our PV generation was lower than it should have been by an estimated 500-600kW. Hopefully nothing like this happens again in future years.

…and then at the very end of that post:

I’m looking forward to doing another one of these posts in a year’s time. Hopefully I will have nothing at all interesting to report.

Alas, something “like this” did happen again, and I have some interesting things to report.