Solar and electric cars go together like peanut butter and jelly. If you have a solar electric system, it's almost a no-brainer to add an electric car to your system so that your transportation can be less expensive and emissions-free. But how do we break down the cost savings and emission savings to ensure we're making the best choices? 

Check out the following tools to help you decide what car to choose, and how best to set up your solar system so you can drive on sun power.

Electric Vehicle Basics

First let's take a look at some of the basic questions most people ask about  owning an all-electric vehicle (EV). What is the range, and equivalent MPG of an EV to a gas-powered car? How much will charging the electric car cost? And how much cleaner is an EV to run over a gas-powered car?

Range and MPGe

The first thing many people ask about EVs is the range, and this varies by the model. For a full list of 2020 options, check out this great round-up published by the Alternative Fuels Data Center.

Another important thing to know is how much power your car will require for each mile traveled.  Since electric cars don’t run on gasoline, the EPA rates them based on how many kilowatt-hours (kWh) it takes for the car to drive 100 miles, which they convert to a “miles-per-gallon equivalent” (MPGe). You can use FuelEconomy.gov to find and compare the kWh/100 miles and MPGe ratings for all of the electric vehicles on the market in the United States. You'll find that most EVs have an MPGe rating of between 70-140 miles-per-gallon equivalent. 

Cost Savings of Driving on Grid Energy vs. Gas

The next piece of information to know is how much it's going to cost to run an electric car with grid energy (typical electricity that comes from your utility company) rather than gasoline. The Department of Energy has a great calculator called EGallon that shows you your savings based on fuel costs in each state. On average, it costs about half as much to power your car with electricity than gas. 

Carbon Emissions Savings with Grid Energy vs. Gas

Once you have a handle on how much it'll cost to power an EV over a gasoline car, the next step is to see how much lower your carbon emissions will be. Even though grid power is still made up of power sources that cause greenhouse gas emissions, like natural gas, your emissions will still be cleaner by charging your car with electricity.

You can check out how much cleaner it is to drive an EV in any given area and depending on car type with the EPA's emissions tool. This tool will give you the average equivalent emissions for an EV vs. a gasoline powered car depending on your local energy mix.

For example, the electricity that comes from the power grid in VA and MD comes mainly from natural gas and nuclear, with some coal and very little (1-2%) renewable energy thrown in. In these states it's about 70% cleaner to use an EV charged with grid power. Shout-out to DC for having 15% solar in their mix, with biomass and natural gas making up the rest. In DC, it's about 80% cleaner. 

So how do we get to the least expensive option and zero emissions? We go solar!

Many people own an EV without installing solar panels, and as we've seen, their emissions and cost of operation are still reduced. But there's nothing cooler than having an electric car that runs off the sun, giving us free power and zero emissions. As long as your solar system is sized to cover the electricity needs of the home and the car, your utility bill will be minimal, even if you charge your car when the sun's not shining. 

Solar and Tesla

Right-size your solar project for an EV

Our solar experts can help you figure out how to size your solar system to accommodate an electric car. To get a general idea, you can use the MPGe rating tool we talked about above to help you figure out how much average energy your electric car will need. For example, the 2014 Nissan Leaf, an all-electric vehicle, has a combined fuel economy rating of 30 kWh/100 miles – this means the Leaf requires 30 kWh of electricity to drive 100 miles. If you drive 25 miles on an average day, that means you’re using approximately 7.5 kWh of electricity per day – or just over 2,700 kWh of electricity in a given year. This is the “extra” amount of electricity you’ll need your solar energy system to produce.

Armed with this information, you can work with your solar consultant to design a solar panel system that will generate sufficient power to cover both your home and your electric car. All you’ll need to complete the package is an electric car charger.

Add Tesla Powerwall storage for true zero-emission transportation 

One last thing to think about: to make your EV truly zero-emission, it helps to add home battery storage. Many EV/solar owners choose to charge their cars overnight, but of course your panels aren't producing when it's dark out. Your utility bill will still be low because of net metering, but you'll be pulling from the grid and using natural gas to power your car. Solve this by storing your solar energy in your Tesla Powerwall and discharging it into your car overnight. Home battery storage helps you manage your power use and ensure that you are always charging your EV with the sun and not grid power. Check out what some of our customers have said about their home battery storage systems!

Reach out to our solar consultants today for a free, virtual consultation. They can walk you through all of the options and help you decide how to best set yourself up for a zero emissions lifestyle. They'll also let you know about current tax credits and other incentives, as well as the amazing rates we can offer for clean-energy-specific loans through Clean Energy Credit Union. The federal incentive tax credit is currently set at 26%, but steps down soon. It includes solar, battery storage and electric vehicles, so get your project started today and take advantage of that great incentive! 

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