Question 1

How many solar panels do I need to charge my EV?

Accepted Answer

It depends on how far you drive, your car's efficiency, and how much sun your area gets. A typical driver covering 12,000 miles a year needs roughly 3–4 kW of solar — about 8–10 standard 400W panels — to generate as much energy annually as the EV uses for charging.

Question 2

What are peak sun hours?

Accepted Answer

Peak sun hours are the daily equivalent of full-strength sunlight (1,000 W/m²) your location receives. The Southwest averages about 5.5–6 hours, while the Northeast is closer to 3.5–4. Fewer sun hours means you need more panels to produce the same energy.

Question 3

Does solar fully replace charging from the grid?

Accepted Answer

Not exactly. This sizing offsets your EV's energy on an annual basis, but solar produces during the day while most charging happens at night. Net metering or a home battery lets you bank daytime production to cover evening charging — how much you self-consume varies by utility and schedule.

Question 4

Why include charging and system efficiency?

Accepted Answer

AC charging loses some energy as heat (about 10%), and a solar array loses energy to wiring, inverter conversion, heat, and soiling (about 20%). Accounting for both gives a realistic panel count instead of an idealized one.

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