Zero Electricity Bill and a Car That Runs on Sunshine: Solar + EV at Home

Most families think of solar as a way to reduce the electricity bill. But once you add an electric car, rooftop solar becomes something bigger: a personal fuel station on your roof. With the right sizing, you can bring your net electricity bill close to zero and run your car on sunshine.

Step 1: Know your home consumption

Look at your last 12 bills. A typical North Indian family home uses 250–500 units a month, peaking in summer. Under PM Surya Ghar, systems up to 3 kW get up to ₹78,000 central subsidy.

Step 2: Add your car

Most compact electric cars use about 0.12–0.15 kWh per km. If you drive 40 km a day (about 1,200 km a month), the car needs roughly 150–180 units a month.

Based on ~120 units per kW per month (North India average). Actual generation varies with orientation, shade and season.

Step 3: Let net-metering be your battery

Your car usually charges in the evening, when the sun has set. With net-metering, the surplus your panels export during the day is credited to your account, and the units you draw at night to charge the car are offset against those credits. You do not need a home battery to “run the car on solar” — although a hybrid inverter with battery adds backup during outages and lets you charge from stored solar.

The economics

*Indicative running-energy cost for a compact car; depends on tariff, vehicle efficiency and fuel price.

• Pick a hybrid inverter if you want backup + future battery
• Leave space on the distribution board for a 7.4 kW AC charger
• Consider a solar carport if roof space is limited
• Use scheduled charging to align with solar hours on weekends/work-from-home days