EV Home Charging 101

How to Charge an EV at Home

You can charge your EV on the go and at charging stations, but 80% of electric vehicle charging happens at home. How does it work, and what are your options? Here is everything you need to know to charge your EV at home.

How Does an Electric Vehicle Get Charged?

A lot happens under the hood to store electricity from the grid into your electric car’s batteries.

What is EV Charging?

Ninety percent of Americans travel by car and spend an average of 101 minutes a day in their vehicles. It should be no surprise, then, that it is estimated there are 150,000 gas stations across the United States. As we quickly shift to driving electric vehicles, many are shifting their mindsets to ensure they have enough electricity in their batteries before setting out on the road. While more public charging stations are popping up across America, it is estimated that 80% of charging happens at home. This is prompting more EV owners to ask questions like: “How can I charge my EV at home?“

What are the basics of EV charging, and how does it work? Regardless if you are a new EV owner or thinking about buying an EV in the future, below are a few things you should know about how EV charging at home and on the go works for your new vehicle.

What Is An EV Charger?

Electric vehicles require an EV charger to keep their batteries full just like any electronic device in you home. But unlike traditional plugs used for home electronics, EV chargers come in a range of solutions – some unique by manufacturer. The charging cord connects electricity from your home to the charge port in your car much like a hose would connect gasoline from the pump to your tank.

How Does a Home EV Charger Work?

Most electric vehicles are charged with two way alternating (or AC) current from a Level 1 or Level 2 charger. Many cars can also be charged with direct (or DC) current from a Fast Charger.

In either case, energy flows through the charge port (item A in the diagram). From here, AC current is converted into DC current by your car’s on-board charger (item B). Current can then flow into the batteries (item C) for future use by your electric motor (item D).

What are the Differences in EV Chargers?

There are three main options for charging electric vehicles in the United States – Level 1, Level 2, and DC Fast Charging. Conveniently, almost all EVs can leverage any of these options with adapters.

What EV Home Charging Options Do I Have?

Charging an electric vehicle is mainly done at home, but not all home chargers are the same. It’s important to understand the solutions available so you can find a solution that best fits your needs and driving behavior. Here at Dominion Energy Solutions, we install EV chargers for homes.

Level 1 Charging

Every electric vehicle is sold with a Level 1 charging cable. These cables can be plugged into any standard 120V outlet in your home or garage. The energy transfer is slow, and it can take upwards of 20 hours to fully charge your batteries.

Level 2 Charging

Level 2 chargers use a 240V outlet shaped like the one used by clothes dryers or ovens. These chargers are typically purchased separately and mounted on the wall where you plan to charge your car; however, some EV car manufacturers offer portable Level 2 chargers. Regardless if the hardware is intended to be portable or mounted in a fixed position, it is recommended you hire a professional to install the 240V outlet that every Level 2 charger requires.

The benefit of purchasing a Level 2 charger is time savings; time to fully charge your car can go from 20+ hours with a Level 1 charger to somewhere between 4-12 hours depending on your vehicle.

DC Fast Charging

Homes are powered by AC current, which means DC Fast Charging (or DCFC) is only available on-the-go at charging stations. Sometimes referred to as Level 3 chargers, these charging stations send 480 volts of direct current (DC) to your car resulting in much faster charging times. Many cars can be fully charged in 30 minutes.

Which Home EV Charger Is Right For Me?

There are two standards for home charging, Level 1 and Level 2, and all electric cars can be charged with either. The differences between the two can be understood in two ways.

The first way to see the difference between Level 1 and Level 2 charging is how long it will take to fully charge your car. As you can see in the chart below, Level 2 charging is much faster than Level 1 charging.

The second way to see the difference between Level 1 and Level 2 charging is “miles per hour” – but in this case we don’t mean how far your car will travel per hour but rather how many miles you can store per hour of charging. This is important if you just want to top off with enough power to get where you are going rather than fully charge your batteries. Below outlines the common times it takes for each level of charger to both fully charge your batteries and how many miles you can expect per hour of charge.

When is the Best Time to Charge My EV?

Whereas the price of a gallon of gas is the same no matter what time of day you fill up your tank, the price of electricity can vary depending on where you live in the country. Some utilities still charge the same price per kWh regardless of time of day, but many electric utilities now offer incentives if an electric vehicle owner signs up for one of two typical programs: Demand Response and Time of Use.

Demand Response and Time of Use Programs

Demand Response programs provide an opportunity for consumers to play a significant role in the operation of the electric grid by reducing or shifting their electricity usage during peak periods. In signing up for this type of program, electric vehicles owners will notice that their utility will take over and adjust the speed of charging at times of peak demand on the grid. In return, these customers receive financial compensation usually in the form of cash rebates on their electric bills.

Time of Use programs outline different prices for electricity based on time of day, usually with the cheapest prices happening after midnight/before 5:00 AM and the highest prices happening during weekday afternoons. Electric vehicle owners who sign up for this type of program often set their cars to charge after midnight to get the best rate on the electricity they consume.

While many utilities only offer one of these incentive programs, Dominion Energy offers both for EV owners. For those interested in Demand Response, Dominion Energy offers EV Charger Rewards. Under this program, and in exchange for allowing Dominion Energy the ability to shape your behavior, EV owners can receive a $125 rebate on a Level 2 charger and receive an ongoing annual $40 participation reward.

For those interested in Time of Use programs, Dominion Energy offers Off-Peak Plan. Anyone with a smart meter within the Dominion Energy service area can sign up for this program and pay different rates depending time of day. Since EV charging is relatively easy to shift to the nighttime, many drivers opt to enroll in time-based pricing and then set their charger to run during the lowest-cost hours (12am – 5am). For many drivers, this also happens to be the most convenient way to charge.

So which option is best for you? Here’s a comparison of the key benefits:

Looking at your unique usage can help you compare the financial benefits between the two options. Customers with 12 months of smart meter data can review the bill comparison graph and chart in their online account portal to understand their expected benefits and how they compare with EV Charging Rewards benefits.

Can I Charge My Car Using Solar Power?

In addition to getting asked about how to charge an EV at home, we often get asked about how to pair an EV charging station with solar power. Driving electric is cleaner than driving a gas vehicle in every corner of the country, but just how much cleaner depends on the electricity that powers your car. If you have a very low-carbon electric grid serving your home, then charging at home will be even cleaner than if your home is powered by a relatively carbon-intensive electric grid. Utilities across the country are working to reduce the carbon impact of their electricity production, so it is likely that the carbon content of your electricity will decrease over the life of your vehicle.

Virginia residents who have Dominion Energy as their electricity provider have numerous options to ensure the energy they consume is low-carbon or even carbon free. These range from 100% Renewable Energy, Green Power, and a Community Solar program now accepting pre-enrollment.

But what about charging your electric vehicle with a solar system installed on your roof? If you install rooftop solar, it can power your home (and your EV) with carbon-free electricity. Rooftop solar is a great way to save you money on your electric bill, increase the value of your property, and help to protect the environment by generating clean electricity, and Dominion Energy Solutions offers customized solutions for all residents in Virginia.