Will solar power change my gas bill or just the electric bill? Adding solar PV to your structure typically will not lower your natural gas bill, just your electric bill. You do have the opportunity while sizing the solar PV system to make changes that will lower the gas bill. If you know that your gas hot water heater is on its last legs you can up-size the solar PV system slightly and replace the hot water heater with an electric heater that uses your free clean solar electricity to produce hot water. Or if you have rooms that your gas furnace never quite keeps warm enough so you’re always turning up the thermostat to compensate, we can install electric heaters in those rooms, up-size the PV system and allow you to lower your home thermostat and save gas.