This system, designed by Michael Jahrer from Graz, Austria, has been developed over the years, starting in 2020, with minimal changes since October 2022. Since then, it has delivered 46,356 kWh of AC energy and continues to perform reliably. It is an off-grid 3-phase system with 86 kWp of PV panels and over 100 kWh of lithium battery storage. Optional AC grid chargers are available to support during adverse weather conditions. The system powers two houses, with heating provided by deep-drilling heat pumps. It also charges three electric cars and runs several air conditioners during the summer.
The focus of the entire build is on using cost-efficient components that perform effectively. The battery setup is primarily a 14S LiFePO4 configuration with a voltage range of 42-47.5V, handling the substantial current through a divide-and-conquer approach. The charge controllers, batteries, and inverters are connected to a central 400mm² busbar capable of handling 500A continuous current. The plant room is air-conditioned to ensure components remain cool during the summer months.
The PV panels are divided into 22 arrays, each connected to a modified 60A PowMr charge controller. The largest arrays are 5.7 kWp. The six PowMr inverters used for generating AC can be stacked in parallel, consuming 10 kWh of standby energy per day. In winter mode, Michael runs only one inverter per phase, reducing the standby consumption to 5 kWh per day. Overall, the setup runs incredibly well and remains stable. Michael Jahrer is very pleased with all the PowMr components.
