Solar payback for EV owners: 4-7 years instead of 10

If you drive an EV, your annual electricity use roughly doubles compared to a typical home. Each kW of solar offsets more grid spend, so your panels work harder per dollar invested. A US household with a Tesla Model Y driving 12,000 miles a year uses ~3,400 extra kWh of electricity. At 0.17 dollars per kWh, that's 580 dollars a year , a non-trivial expense. Add 4 kW to your solar system (about 12,000 dollars before ITC), and you offset that EV cost completely. After 30% ITC, your net is 8,400 dollars, and your payback is 5 years vs 7-10 years for solar alone.