Can I Use My Electric Car As A Backup Solar Battery at home?

Updated: March 5, 2022

If you have a solar panel system or are thinking of installing one, the most expensive part is the battery, but if you already own an electric car, you will soon be able to use it to power your home at night.

Electric cars have a large battery to store charge and to enable travel over long distances before the next charge. The Tesla 3 for example has a 75kW battery. That is enough charge to power the average home for 3 days without recharging.

The future of power storage is EV’s with bidirectional charging, which allows you to use and distribute power as you see fit.

This refers to two-way charging where a battery can draw energy from the grid or supply the grid with power.

Vehicle to Grid

This is an EV charger that is able to send power from your vehicle to the grid to sell back to the utility company or to a third party power supplier. During the day in off-peak conditions your battery can be charged by either drawing cheaper power from the grid or from a rooftop solar array. At night when power is more expensive, you can feed that power back into the grid earning money based on the difference between peak and off peak prices.

Vehicle to home

This is very similar to Vehicle to grid, but instead of selling your stored power for money, you use it yourself at home. The EV battery will charge through the days with a rooftop solar system and then deploy that power at night to be used at home.

Is the technology ready?

From the date of writing this article, Nissan boasts it’s new LEAF electric car will be released in 6 months and will be capable of powering your home just by plugging it in.

Currently a roof top solar system requires an inverter to manage the power to be used by your home and what gets sent to the grid. I imagine they will need either a new type of inverter to factor in your car, or just an updated program that talks to your EV so it knows how much power is in the battery at any given time.

In short, we have the tech, and we are just months away from it being a reality.

Purpose Of A Solar Battery

A solar battery is a battery that is part of the solar PV system for your home. It stores excess power produced by your solar panels.

A solar battery makes it possible to become energy independent. The amount of power stored in the batteries can be used at night and on cold and cloudy days when there isn’t much electricity from the panels. Reducing reliance or the need for grid electricity.

A solar battery is expensive. Not many households can set up a solar battery system at the same time as the solar panel system. Can an electric car be an alternative or a backup solar battery?

Solar Battery

Can You Use Electric Car As A Backup Solar Battery

Yes. You can use an electric car as a backup solar battery. Your electric car can easily power your house when it is charged.

For many homes, a 10kWh capacity solar panel system is more than sufficient to power it. A 6.6kw capacity solar PV system is the most commonly installed solar panel system. Coupled with a battery system, you can eliminate expensive electricity bills and keep the lights on in your home even during a blackout.

An electric car runs on a rechargeable battery. Depending on the type of car you buy, the battery capacity ranges from 40 to 65kWh. Electric car batteries have much larger capacities than solar battery systems.

Depending on how you use your electric vehicle, you can use it as a backup solar battery. For many, electric cars are only used for the commute to work. For most of the day, the electric car is parked. Thus, when you get back home, a fully charged electric car still has a high charge.

You can use power from your electric car to power your home for the remainder of the evening if you don’t have a solar battery system.

Benefits Of Using Electric Car As A Backup Solar Battery

Save big money

A Tesla Powerwall 2 costs about $12,000 installed. Using your EV’s battery to power your home at night will save you this large outlay of money.

Charge Car And Power Home Simultaneously

Where it is possible to use your electric car to power your home, you can also charge your car at the same time. You can save time and money and also ensure that your home is powered continually.

When you are ready to go, the car is also fully charged and has enough power for the commute.

Challenges Of Using Electric Car As A Backup Solar Battery

Infrastructure

Few companies around the world make charging infrastructure for electric cars that make it possible for the cars to power your home. This makes it difficult for homes that want to rely on their electric cars as backup solar batteries.

Since these are still new products in the market, it takes some time before the manufacturers can deliver the devices to your home.

Cost

Electric cars are still more expensive than fuel-powered cars to buy on average although prices are tumbling year over year as more car manufacturers get on board the EV revolution.

That being said, EV’s cost a lot less to run. You can charge your Tesla S 100KW battery for about $25.00. That will get you 1000kms of range. That makes petrol cars about 400% more expensive to run.

Install Solar In Your Home

Gosolarquotes.com connects you to professional solar panel system installers. Before you install solar panels, talk to at least three installers on the cost and best solar panels for your home. This tool makes it easy to compare prices and find the best panels.

Enter your location in the space provided. Then, fill the subsequent form to provide information on your solar installation project.

Your information will then be sent to professional installers. You will be contacted by at least three installers with advice and quotes for how much your project will cost.

You can pick any of the three installers to install solar panels in your home.

FAQ's

To find out the solar system capacity you need for your home, you need to assess your current electricity usage. To do this, you need your electricity bill. Your electricity provider will indicate how much electricity you use annually, monthly or quarterly. You can use this to determine the capacity of the solar system you need.

Depending on the size of your household, your daily power needs range between 20-24kw. Thus, a 6.6kw capacity solar system is enough to power all your home needs.

You don’t need a large-capacity solar system to charge an electric car. A solar system capacity ranging from 3-10kW can power your home and charge an electric car.

When installing solar panels, it is essential to consider your future electricity needs. If you think you will use more power than you currently use, installing a larger solar system is the best solution.

It is affordable as you will receive a higher discount for installation and it will serve your future electricity needs without additional cost.

What Solar System Capacity Do I Need To Charge My Electric Car

Whether you need a permit to install solar panels on your roof depends on where you live. Hire a pro to install solar panels for you. They will advise you on whether you need a permit to install your solar panels. You can also visit your local government office to find out.

How much power a solar system produces is determined by the amount of sun it receives. If you live in a sunny region, you can expect your solar system to produce more power than if you live in a colder region.

As the day progresses, how much sunshine reaches your solar panel also differs. Early morning and late in the afternoon, there is little sunshine on your panels. At this time, the solar panels produce less power.

At midday, when the sun is shining directly on your solar panels, they produce at optimum.

With a solar battery system, you can enjoy additional benefits from your solar panel system. First, you can become totally energy independent. This means that you can go off-grid. Solar batteries store excess power produced by your solar panels. You can use the stored energy at any time you need power whether the sun is shining or not.

Depending on the size of your solar batteries, you can move them around to charge other portable home appliances.

Installing a solar system in your home is worth it regardless of where you live. The cost of solar panels is coming down as more and more people use solar. As a new solar customer, you can get a government rebate that helps to lower the cost of purchase and installation.

Additionally, installing solar panels in your home helps to reduce or eliminate your electricity bill. If you are partially reliant on grid electricity, you will make large savings as your bill reduces.

Further, solar panels are cost-effective with no maintenance required and long life.

Depending on the type and brand of solar panels you install, you can expect them to serve you for about 25-30 years. Once you invest in solar panels, you can expect to recoup your investment in 5-7 years based on your electricity usage.

For the remainder of the life of the solar panel, you can enjoy free electricity until you need to replace the solar panels.

Ben McInerney head shotAuthor: Ben McInerney is a renewable energy enthusiast with the goal of helping more Australians understand solar systems to make the best choice before they purchase. Having an accredited solar installer in the family helps give Ben access to the correct information, which allows him to break it down and make it easily understandable to the average homeowner.