It’s true: solar power’s becoming more affordable. Here’s how to keep rooftop photovoltaics open as a future option for homes with a south-facing roof.

Pete Sucheski

1. The Panel “Grid-tied” solar systems tie into the home’s electric panel and feed excess production back to the utility. Reserve two spaces in the electric panel for a 240-volt breaker.

2. The Inverter Smart electronics convert direct current (from the panels) into alternating current (used by the house and by the power utility). Save space for an inverter next to the main panel.

3. The Wiring Rooftop solar panels typically feed high-voltage direct current down from the roof to the inverter, which then supplies the house. Provide a run of conduit from the inverter to the rooftop to contain those heavy-gauge DC wires.