In the summer of ’24 I replaced my North roof (project info). A complication was that the roof was under my solar array. The following graph explains another complication, my desire to add more solar panels:
The blue bar is my household energy (all electric) consumption and green is electricity to power our electric vehicles. In most years, I produce enough solar (yellow) to nearly power the house. In the last two years the house power consumption has been less and that extra solar was car fuel. I’ve calculated my Levelized Cost Of Electricity at $0.05/kWh. That’s a substantial discount from grid power so it’s advantageous to buy more panels and produce more fuel for the cars.
As part of the roofing project, I removed and rebuilt my solar array (details here) and upgraded two of my subpanels. What I didn’t know when I did the work in the summer of 2024, was that the soon-to-be-adopted 2023 electrical code requires that all electrical panels have a SPD (Surge Protective Device). By the time I scheduled my final inspection, the newer code was in force and that was the only correction Inspector Friendly required of me.
Despite not being required (grandfathering), I had already installed a SPD in the main panel, since it seemed to me like really cheap insurance. I had also installed a Midnight Solar (MNSPD-300-AC) SPD in my PV combiner box, so now I have 4 SPDs. It feels a tiny bit excessive, until I think about how much it would cost to replace a panel full of AFCI/GFCI combo breakers.