Tempe is the most densely developed city in the Phoenix metro, and its older housing stock — primarily built from the 1960s through 1990s — means solar installations here often require additional panel upgrades, roof assessments, or electrical panel upgrades before installation. That said, Tempe’s location adjacent to ASU and its large rental-conversion and owner-occupier market creates a steady demand for solar. Tempe is served by APS. The average Tempe home is smaller than surrounding suburbs, so system sizes tend to run 8–12 kW at a cost of $17,000–$26,000 before the 30% federal tax credit. For condo owners or renters, community solar programs are worth exploring — Arizona’s grid-connected virtual net metering allows participation even without rooftop access. All solar installers listed here are licensed with the Arizona ROC and verified active. Ask any installer about their experience with older homes and panel upgrade requirements before signing a contract.