Solar Power and Electric Vehicles: How Home Batteries Enhance the Connection

Are you part of the growing number of electric vehicle (EV) owners or thinking about purchasing one soon? You’re in good company as a significant number of Bay Area homeowners have made the switch to electric cars, avoided high gas prices, and now enjoy substantial savings every month.

However, the average EV, driven under regular conditions, requires roughly 5,000 kWh of charging a year. If you rely on PG&E’s electricity to charge your electric vehicle, you likely won’t see the significant savings you’re hoping for. This is because Bay Area residents are already dealing with some of the steepest electricity rates nationwide, and they’re expected to rise.

One major solution is charging your electric vehicle with solar energy, which can make a significant dent in both your monthly PG&E bills and how much you spend on gas. Plus, if you charge your EV during off-peak hours with PG&E’s electricity, you’ll enjoy even bigger savings.

With solar energy, you can protect yourself from the fluctuating costs of traditional energy sources and make your transition to EVs an economical and environmentally conscious choice. In this post, we’ll discuss how solar power, electric vehicles, and home batteries can save you money on your energy bills, give you more control over your energy use and power your EV for every drive.

Understanding Solar Power, Electric Vehicles, and Home Batteries

How Solar Power Works

Photovoltaic (PV) solar panels harness the sun’s energy and convert sunlight into direct current (DC) electricity, which is then converted to alternating current (AC) electricity by an inverter. The resulting energy powers your home, which can reduce or even eliminate your reliance on the grid.

Electric Vehicles: An Eco-friendly Drive

Electric vehicles run on electric motors, rather than internal combustion engines, which means they produce zero direct emissions. Since they’re powered by rechargeable batteries, EVs are not only environmentally friendly but also incredibly energy-efficient, which translates to significant savings on fuel costs.

Home Batteries: Storing Excess Energy Generated by Your Solar Panels

Home batteries like the Tesla Powerwall and SunPower SunVault are storage systems that store any excess solar energy generated throughout the day. This stored energy can be used during peak demand hours, when the sun isn’t shining, or to charge your electric vehicle (even when the grid is down). This can lead to significant savings on your energy bills, especially if you live in an area with high electricity rates.

A 2015 survey conducted by the California Clean Vehicle Rebate Program found about 40% of California electric vehicle owners had a solar PV system installed at their home, or were planning to install one. This means there are an estimated 1.4 million California EV owners who already have solar panels on their roof or planned to install them.

How Many Solar Panels Will You Need to Power Your Home and Charge Your EV?

Determining the optimal number of solar panels to install to charge your EV will depend on your unique driving habits and the specific type of EV you drive. To calculate the number of panels required to power your electric vehicle, you’ll need to look at these three data points:

  1. Your car’s annual electricity consumption,
  2. The power output (wattage) of your solar panels, and
  3. How much electricity your panels generate in your area

Based on the Federal Highway Administration’s report for the average miles an American travels per year by car (about 13,500), the average EV will need about 4,000 kWh of electricity per year.

According to an EnergySage Solar Marketplace Intel report, most solar panels fall within the 320 to 330 Watt range. However, SunPower’s Equinox® A-series panel is equipped with the latest Maxeon® Gen 5 solar cells, which is the world’s first 400 Watt panel.

The electricity generated by your solar panels will fluctuate depending on your location. For example, systems in our sun-drenched state of California tend to perform better than the less sunny regions.  

When you combine these data points, you get a clearer understanding of the solar power needed to charge various types and sizes of electric vehicles in different parts of the country each year. Generally, you’ll find that around 7 to 9 solar panels should charge your electric vehicle, depending on your location.

Remember that these estimates are based on the assumption that your annual mileage is similar to the average American driver. If you drive less than 1,000 miles a month, your electric vehicle’s solar power requirements (and number of solar panels) will decrease.


Overall, pairing your solar system with a home battery is a powerful combination that can charge your EV and help save you money on your energy bills, reduce your carbon footprint, and give you more control over your energy use.

If you’re ready to power your home with solar energy, contact us today to schedule your online appointment


Related Links:

5 Ways Switching To An Electric Vehicle Can Save You Money

Electric Cars 101: The Answers to All Your EV Questions

Electric Vehicle Tax Credits & Incentives

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