That's the neat thing, it doesn't have to. Every kWh that goes into these batteries is a kWh not purchased from the grid. The payback for the solar panels wou

That's the neat thing, it doesn't have to. Every kWh that goes into these batteries is a kWh not purchased from the grid. The payback for the solar panels would very quickly add up. In fact, trying to 100% charge the batteries via solar would not be the most economical way to operate as then you are just wasting money sending power back to the grid.