I'm on my second Nissan Leaf EV. I also own a diesel VW campervan which is used fairly frequently thoughout the year. House is fully electric except for LPG cooktop. Water heating is via water solar collector on roof plus EcoDan heat pump which also heats two hot-water radiators in the living area of the house. No other space-heating.In January 2022 I contracted New Plymouth-based company Natural Technologies Ltd., to install 22 x SunPower SPR-P3-380W solar panels on the roof of my shed. These panels have integrated micro-inverters. Hence all cabling is 240V AC, not high voltage DC. Cost around $25,000.At this time I changed my electricity supplier from Meridian to Our Energy Ltd as they have a much better arrangement for selling surplus power to other Our Energy customers on the Taranaki Powerco network. Buy and sell at $0.12 per kWh.In April 2022, I started monitoring the performance on a speadsheet. From 1st April 2022 to 31st December 2023 the average cost per kWh was $0.102. In December 2023 I contracted Natural Technologies again to install 4 x 5kWh Enphase batteries. Cost around $33,000. From 1st January 2024 to 17th March 2024 the average cost per kWh was (minus) -$0.103. Currently in credit to $86 for the year-to-date. So far, I'm very pleased with the decision to install PV panels and battery back-up.