Solar + EV Charging ROI Calculator

No, not for a homeowner buying a system outright. The One Big Beautiful Bill Act (OBBBA, signed July 2025) repealed both the EV federal tax credit (IRC §30D) and the residential solar tax credit (IRC §25D), the latter for any system placed in service after December 31, 2025. A separate business credit (IRC §48E) still runs through 2032, but that only benefits third-party owned systems such as solar leases or PPAs, where the leasing company claims the credit, not a homeowner who buys or finances their own system. If you placed your system in service by December 31, 2025, your 30% credit is unaffected. This calculator no longer applies a federal credit to purchased systems.

A rule of thumb: 1 kW of solar capacity produces roughly 1,200–1,800 kWh/year depending on your location. An EV driven 1,000 miles/month uses about 317–400 kWh/month (3,800–4,800 kWh/year). At 3.5 mi/kWh with 90% charger efficiency. To cover your EV alone: 2–4 kW of additional solar. Most homeowners add 1–2 kW beyond what their home needs. Use the system size slider above to see exactly how much of your total energy (home + EV) your proposed system covers.

LCOE (Levelized Cost of Energy) is the total lifetime cost of the solar system divided by the total lifetime energy it produces — your effective cost per kWh over 25 years. In 2026, residential solar LCOE ranges from $0.04 to $0.07/kWh depending on system cost and sun hours. At $0.05/kWh LCOE vs your grid rate of $0.18/kWh, every kWh of EV charging from solar costs 72% less than from the grid.

Net metering credits you for electricity your solar panels export to the grid when you generate more than you use. Most states credit you at your full retail rate (100%). California’s NEM 3.0 (2023) dramatically cut export credits to ~25% of retail, making battery storage more attractive there. The export rate you set in this calculator directly impacts your annual savings.