I think the person you are replying to is suggesting using PV panels to heat a thermal mass (using resistive heating or possibly a DC heat pump) to avoid the ex

I think the person you are replying to is suggesting using PV panels to heat a thermal mass (using resistive heating or possibly a DC heat pump) to avoid the expense of an inverter and other electronics necessary to connect to the grid. This is actually a pretty good idea now that PV panels are a much smaller percentage of the total cost of solar nowadays.