Your electric car can power your house in the future

 

Electric car demand is continuously increasing as manufacturers release new models. New electric vehicle sales in the United States nearly doubled in 2021 and are expected to double again in 2022, from 600,000 to 1.2 million. Automakers predict that by the end of the decade, electric vehicles will account for at least half of all new car sales in the United States.

Electric vehicles appeal to a variety of clients in different ways. Many purchasers want to contribute to environmental protection; others want to save money on petrol or check out the most cutting-edge technologies.

Consumers in states like California and Texas, which have seen huge weather-related power outages in recent years, are beginning to think of EVs in a new light: as a potential source of electricity when the lights go out. The electric F-150 Lightning pickup truck, which is expected to hit dealerships in the spring of 2022, offers backup power as a selling factor. The vehicle, according to the business, can power an ordinary home for three days on a single charge.

However, only a few cars can now charge a house in this manner, and specific equipment is required. V2H (vehicle-to-home charging) also offers a problem for utilities. Here are some of the major difficulties that must be addressed in order to push V2H into the mainstream.

Vehicle-to-Home Charging's ABCs

The size of the vehicle's battery and whether it is set up for "bidirectional charging" are the two most important considerations when utilizing an EV to power a home. Vehicles with this capacity may charge their batteries with energy and deliver power from a charged battery to a residence.

There are two methods for determining the size of a battery. The entire amount of electric fuel stored in the battery is the first. Because it dictates how far the car can travel, this is the most often touted figure from EV manufacturers.

Electric sedan batteries, such as those used in the Tesla Model S and Nissan Leaf, may be able to store 80 to 100 kilowatt-hours of electric power. A kilowatt-hour of energy is enough to operate a conventional refrigerator for five hours.

Depending on the size of the home and the appliances used, a typical American home uses roughly 30 kilowatt-hours each day. This indicates that a standard EV battery can store enough electric fuel to meet a normal home's complete energy demands for a few days.

Chart: The Conversation, CC BY-ND  Source: Oak Ridge National Laboratory

The maximum power output in backup power mode is another technique to analyze an EV battery's capacity. At any one time, this reflects the highest quantity of electric fuel that might be provided to the grid or a dwelling. When an EV is in backup mode, its maximum power output is often lower than when it is in driving mode. The backup power capacity is significant since it reveals how many appliances an electric vehicle battery can power simultaneously.

This statistic isn't as well known for all EVs, owing to the lack of widespread usage of vehicle-to-home charging. Ford has said that the electric F-150 will have a maximum V2H power output of 2.4 kilowatts, with the ability to be upgraded to 9.6 kilowatts — about equivalent to a single Tesla Powerwall home energy storage unit.

On the low end, 2.4 kilowatts is enough to power eight to ten refrigerators at once, and could power most of a normal home for a few days – or much longer if electricity is utilized wisely. On the high end, a power level of 9.6 kilowatts might operate more or higher-powered appliances, but the battery would be depleted faster.

Storing power when it's less expensive

EV owners will require a bidirectional charger and a V2H-compatible electric vehicle to draw home electricity from their vehicles. Commercially available bidirectional chargers are currently available, however some can add several thousand dollars to the cost of a car.

V2H is now compatible with a small handful of EVs on the market, including the Ford Lightning, Nissan Leaf, and Mitsubishi Outlander. In mid-2022, General Motors and Pacific Gas & Electric intend to test V2H charging in California with a number of GM electric vehicles.

Some homeowners may choose to utilize their car for "peak shaving," which involves pulling domestic power from their EV throughout the day rather than relying on the grid, so lowering their electricity consumption at peak demand hours. They may need to install sophisticated metering equipment to manage both the draining of the car batteries and the flow of electricity from the grid to the residence in order to do this.

Peak shaving makes the greatest sense in regions where utilities charge by the hour, making power from the grid considerably more expensive during the day than at night. A peak-shaving home would charge the EV battery with inexpensive power at night and then store it for usage during the day, avoiding high electricity bills.

The future of V2H and utilities

While V2H capabilities are already available, it will likely be some time before they are widely adopted. The market for V2H-compatible electric vehicles will need to expand, as will the cost of V2H chargers and associated equipment. The main market for V2H, like Tesla's Powerwall, will likely be homeowners who want backup power when the grid goes down but don't want to invest in a dedicated generator.

Allowing residents to use their cars as backup power when the electricity goes out would mitigate the social consequences of widespread blackouts. It would also allow utilities more time to restore service, especially when electricity poles and lines are severely damaged, as they were during Hurricane Ida in Louisiana in August 2021.

To guarantee dependable service, power providers will still have to invest money on creating and maintaining the infrastructure. People without V2H – who are more likely to have lower incomes – may well face a bigger proportion of those expenses than those with V2H, who will avoid purchasing peak electricity from the grid. This is especially true if a large number of electric vehicle owners utilize rooftop solar panels to charge their vehicles' batteries and then use those vehicles to reduce peak demand.

Electric cars are still a large potential market for electric utilities, even with V2H. Bidirectional charging is also an important aspect of a larger concept for a next-generation electric grid in which millions of electric vehicles are continually drawing electricity from the grid and returning it – a critical component of an electrified future. However, energy planners must first understand how their consumers utilize V2H and how this may influence their grid reliability initiatives.