How Many Solar Panels to Charge an Electric Car?
Date:2019-03-28 05:22:34 Posted by:mrpower View:624So many of us are driving electric these days. Also, why wouldn’t we? It’s cheaper, they’re fun, and the technologies come so far that you can depend on the vehicle. However, you might be wondering how many solar panels it takes to charge your electric car? Fortunately, there’s a variety of home charging stations, and if you connect them to solar panels, you can practically charge your car for free. No small fee when you consider the price of gasoline these days.
However, how many solar panels do you need to charge your electric car?
There are limited public charging options
We’re rapidly running into an issue with the number of vehicles vs. the number of public charging stations. While the number of the charging stations is expanding steadily, it’s still a pain to park somewhere and charge your car though. So, if you like the more convenient option, your charging station is the way to go. Moreover, the cheapest way to do this is by using solar panels in conjunction with your charging station.
If you don’t already have solar panels, then your home charging stations going to draw directly from the grid – aka your power supply. The cost of this power is going to run you the same cost as standard electricity per kWh.
Using an average cost of $0.11 per kilowatt hour, the Department of Energy estimates that the cost of charging an electric vehicle with a 70-mile range would be about the same as running an air conditioner for six hours. As you can imagine, that cost can add up over time. Granted, it’s still cheaper than paying for gas, but you can get it even lower with solar.
If you already have solar on your home, you may run into a bit of a quandary. Your current installation may only provide the required power for your home and not enough excess for your car. This means you’ll have to pull power from the grid at the same price as your conventional electricity. To find out if your system has enough power, contact your solar provider and ask. If you’re getting solar panels, then let your dealer know ahead of time that you plan on charging your car and they’ll build the system with plenty of power to handle that task (figure 1).
Figure 1: Electric vehicle charging station
EV Charging Systems and Solar Panels
Combining an electric vehicle charging station with your solar system comes with a variety of advantages, including charging your car for less money. If you have an electric vehicle, this is most definitely the way to go. Also, of course, you get the benefits of having solar panels on your home at that point which also makes your overall home power cheaper and even free after the systems paid off.
The Size of the Battery in Your vehicle
The amount of electricity you need to charge your vehicle will depend on the battery of your car. Some electric vehicles have larger batteries which can require longer/more power. To figure out the amount of power needed, you have to consider a few things. First, your battery capacity is measured in kilowatt hours (kWh).
The amount of kWh for a battery can range anywhere from the lower 20s on up to 100 or higher. For instance, while a BMW i3 battery has a capacity of only 33 kWh and upgraded Tesla Model S has a battery with a capacity of 100 kWh. The larger your battery, the more power you need to get it fully charged. Again, this is something you’ll want to discuss with your solar installer to determine the number of panels needed.
How Many Solar Panels to Charge an Electric Car?
As pointed out above, the number of panels needed for charging your electric vehicle will depend on the size of your vehicle’s battery. However, to consider this question, we’ll use the standard Tesla Model S as a baseline for estimates. This Tesla has a battery with a 75-kWh capacity. Your specific needs for your particular car may be different from this, but you can find that information on your manufacturer’s website.
To figure out how many panels you need to charge your electric vehicle, you have to know the amount of power each of your solar panels can produce. If you don’t already have panels, I’ll save you some time – SunPower panels are the highest efficiency.
The average 250 W solar panel can generate around 30-40 kWh of AC power each month. Let’s make use of the lower number (30 kWh) in our calculations.
Given that single, low output solar panel produces roughly 1 kWh per day of electrical power; this indicates that you need to install as many as 75 solar panels to generate electricity to power your Tesla Model S each day – assuming that you start the charging process with a battery totally drained of electricity.
However, since the average driver will travel approximately 37 miles a day – this translates to roughly 12 kWh of electricity. With that in mind, a much more realistic set would require approximately 12 solar panels. Also, even this is a conservative estimate that’s based on the use of low output solar panels.
If you choose a higher efficiency solar panel system, the number of panels you need for charging up your EV may drop even more. In addition to this, if you drive less than 30 miles a day, the number of panels would drop even further. So a realistic appraisal of not only your car battery capacity – but also use of your car and your solar panel efficiency – can significantly impact the number of solar panels you need. The rough amount for most cars is between 6-12 additional panels.
Conclusion
When you compare solar panels to the cost of gas or the cost of standard electricity from the utility company, they’re the clear, mathematical winner. Solar is the cheapest form of electricity and getting cheaper all the time. It’s also a lot more convenient than driving to a charging station which may or may not be anywhere near your house. So finally, you’re helping to reduce your carbon footprint and protect our environment for future generations.
