How to Charge Your Electric Car From the Sun at Home

In this guide, we will show you how to charge your electric car from the sun at home, and yes, it is possible!

We will also talk about the power requirements, how many solar panels you will need, electric car statistics, and much more.

Let’s jump into it!

Main Purpose

The main reason to charge electric car via the home solar energy is to save money instead of paying for expensive gas.

For long term solar panels use, there’s a way you won’t even need to pay for the electricity for your electric car’s battery.

Let’s start by talking about the power requirements.

POWER REQUIREMENT FOR ELECTRIC VEHICLES

Gas-powered vehicles, on average, have a gas tank size of 18 gallons.

Using an average of 25 miles per gallon, a full tank of gas is enough to get you 450 miles before your next refill.

Electric vehicles work similarly. Electric cars have different-sized batteries that store power, and similar to gas stations, they charge their electricity from power stations.

According to PEW Research Center, an average electric vehicle will need 30 kiloWatt-hours of energy to travel 100 miles—this amount is about how much an average home in the United States uses every day to run its appliances, heating, air conditioning, and other electronics.

So the good news is that it’s more than possible to charge your car at home, which saves you a lot of money. The bad news is that it will most likely use up enough energy to power your house for a day.

As time goes forward and technology improves, more electric cars have been released with better performance and efficiency. Let’s talk about five of the most efficient electric vehicles and their statistics for reference:

Electric car MSRP Range (est.) Charging rate Power capacity Max. power output Charging price

2021 Tesla Model S $69,000 390 mi. 13 miles/min 100 kWh 250 kW $0.25/kWh
2021 Porsche Taycan $104,000 230 mi. 10 miles/min 86 kWh 390 kW $0.42/kWh
2021 Nissan LEAF $32,000 150 mi. 5 miles/min 40 kWh 110 kW $0.13/kWh
2021 Toyota Prius LE $28,000 25 mi. 0.2 miles/min 8.8 kWh 90 kW $0.23/kWh
2020 Chevy Bolt EV $37,000 260 mi. 3 miles/min 66 kWh 150 kW $0.13/kWh

The number of electric cars sold and used has been increasing quadratically ever since 2012. In 2017, over 1.93 million electric vehicles were used, over 3.27 million in 2018, and over 4.79 million in 2019! Researchers and salespeople estimate that by the time 2021 is over, there will be around 16 million electric cars in use, according to Statista.

Since this guide is about charging your electric car at home using solar power, we only focus on the vehicles’ battery capacity. Going forward, just keep in mind that the more battery capacity that your electric car has, the more further it’ll go, but at the same time, the more time and energy it will take to charge your car.

HOW MANY SOLAR PANELS WILL I NEED?

The number of solar panels you’ll need to charge your electric car fully depends on what kind of car you have. Every electric car has a different battery capacity—some vehicles require more energy than others which means that you either have to invest more electricity into your car or more time.

What does kWh mean? KiloWatt-hours, or kWh, is a value found by multiplying the Wattage involved by the time. For example, a 100-Watt solar panel that’s been sitting outside in direct sunlight for 4 hours will capture 400 Wh or 0.4 kWh.

For this example, let’s use a 2021 Nissan LEAF from the table above. We have a wholly drained 40 kWh battery that needs to be charged using solar panels. Using average 300-Watt solar panels, let’s say they each get 6 hours of direct sunlight every day.

300 Watts x 6 hours = 1800 Wh or 1.8 kWh

If we divide 40 kWh from the battery by the 1.8 kWh generated every day from one average solar panel, it will take us about 23 solar panels to charge a 2021 Nissan LEAF in one day. However, most electric cars aren’t charged in just a day. If you have five days worth of electricity saved up:

300 Watts x 6 hours per day x 5 days = 9000 Wh or 9 kWh

In this case, it will only take about five solar panels to charge your car in less than a week.

Other options?

If your house is entirely run by solar power, this would mean that you would have to either cut back on electricity usage and invest some of the electricity towards charging your car, or you would have to buy extra solar panels and maybe another solar battery to dedicate it towards charging your car.

What are the advantages?

The most significant advantage to charging your car at home with solar panels is that you can charge up a solar battery with the panels during the day, and when you come home at night, you can hook up your battery to your car, letting it charge overnight.

Even with just five solar panels, you can still fill about 20% of the battery in a day that is enough to drive you 30 miles—more than enough for an average commute to work and back.

REQUIRED SOLAR EQUIPMENT

The required solar equipment for charging your car at home is almost the same as running your home’s appliances from solar power.

A proper set-up should include the appropriate number of solar panels that you will need—this is entirely up to you, as you can have a few solar panels to charge your car a little bit every day, or you can use many solar panels to charge your car entirely in one go. Other equipment should include a solar battery, a charge controller for the solar battery, a solar inverter, and the correct wires for connecting.

If you plan on connecting the solar panels straight to your car’s battery, it is possible and should be approached with caution. For this, you will only need the solar panels, a solar inverter (if applicable), and the right wires. The disadvantage to this method is that you can only charge your electric car during times of direct sunlight, but if it works with your schedule, it can save you money.

COST ANALYSIS

Investing in extra solar panels and other equipment can be costly. That’s why we have made a handy table* below using the five cars from above to calculate the cost per day, cost per mile, and cost per kWh of going solar.

Electric car Solar power needed # of 300 W panels Cost of panels + equipment Price of solar per day Cost per 100 miles Cost per kWh

2021 Tesla Model S 100 kWh 12 $5,250 $0.58/day $2.10 $0.08
2021 Porsche Taycan 86 kWh 10 $4,650 $0.51/day $1.86 $0.05
2021 Nissan LEAF 40 kWh 5 $3,150 $0.35/day $1.26 $0.05
2021 Toyota Prius LE 8.8 kWh 1 $1,950 $0.21/day $0.78 $0.02
2020 Chevy Bolt EV 66 kWh 8 $4,050 $0.44/day $1.62 $0.06


*For this table, the solar power needed is simply the battery capacity of the car. The 300-Watt solar panels used are multiplied by 6 hours of direct sunlight per day and five days. The average costs of solar panels ($300), a solar battery ($500), a solar inverter ($1,000), a charge controller ($100), and wires ($50) are used. Cost per day is assuming that the solar panels last for 25 years. Cost per mile is assuming each car lasts for 250,000 miles.

Looking at the initial cost of the solar panels, it might seem like something that you’d want to stay away from, but over time, the investment doesn’t seem all that bad. I spend about $30 every two weeks, or $2.14 every day, on gas for my 2017 car. Compared to the Toyota Prius, I would be spending about 90% less just by switching to solar power.

Gasoline takes up a lot of money over the year—the average person is spending $3,000 on gas in a year. By switching to electric pumps, people usually end up paying $1,300 a year. But by using your solar panels, you can cut that cost down to where it would only be costing you $150 per year! That’s 95% less money spent when compared to gasoline which is why a lot of people are making the switch to solar power.

KEY TAKEAWAYS

There is a lot of information within this guide, so we’ve made a TLDR (Too Long, Didn’t Read) list containing all of the essential takeaways from this guide:

An average electric vehicle will need 30 kiloWatt-hours of energy to travel 100 miles.
It will take 8-12 solar panels to charge your electric car over five days.
Solar power and electric car technology are getting more efficient and higher-performing every single year.
Switching from gas to electric pumps will save you 57% of the money spent on gas.
Switching from gas to solar panels will save you 95% of the money spent on gas.

WRAPPING UP

As we wrap up, we’d like to remind you that all of the values used in our examples are simply average values. Some of the cars from the list, such as the Toyota and the Nissan, are everyday electric cars. In contrast, like the Tesla and the Porsche, the other cars are luxury electric cars that are solely included for having extreme values to compare to.

Some of the solar equipment may end up costing more or less, depending on what brand, quality, or type you’re interested in. There are plenty of solar panels out there that outperform the 300-Watt solar panels that we used in our examples—don’t be shy from looking them up as well!

We hope this guide helped you understand how to charge your electric car from the sun at home!

Kabeer Bhatia

Kabeer Bhatia has several years of experience camping and backpacking, and focuses more on the technical side of wilderness technology including solar energy.

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