Following the news of Tesla’s acquisition of U.S. solar installer giant SolarCity, the world has been keeping a close eye on Elon Musk and his two prosperous clean energy ventures. Tesla and SolarCity, electric cars and solar panels – a two-front war waged against grid reliance and energy dependence. In 2019, Musktopia is both expanding and constricting as two of the tech entrepreneur’s five companies are joining forces around one common goal: decimating your carbon footprint.
How to charge a Tesla with solar energy
Many homeowners are wondering if they can charge their Tesla car with solar panels and the answer is you can. An electric vehicle such as a Tesla can serve as battery storage for solar energy. Musk has outlined his newest goal, which he says can be achieved with his one-two punch solution for homeowners seeking alternatives to fossil fuels:
- Install solar on your roof to generate electricity by harnessing the power of the sun
- Take that photovoltaic energy and use it to charge your Tesla Model S
Was this all possible before the Tesla-SolarCity merger? Of course. A Chevy Volt or Nissan Leaf owner didn’t need Elon Musk’s “master plan” to realize that electric cars can be paired with solar energy. But perhaps Musk’s true innovation was in recognizing that solar panels and electric cars are complementary, not substitute, goods and need to be marketed as such.
You might be able to imagine a world where a tablet and a smartphone are viewed as substitute products, but Steve Jobs successfully reached beyond tech’s power-users and created a need for both to exist in mainstream markets. Similarly, Musk’s latest move targets the layman homeowner, extending beyond clean energy’s early adopters who paired their Leaf or Volt with home solar panels years ago.
By bringing two of the world’s leading solutions to emissions reduction under one roof, Tesla can cut operating costs in development and installation, helping homeowners to understand clean energy financing options as a combined cost rather than trying to conceptualize the headache of multiple individual energy investments. In a sense, Tesla is making clean energy simple because it needs to be simple.
With this merger underway and with millions considering the prospect of a zero-emissions home, a number of questions are arising in the renewable space. How do you connect solar panels to an electric vehicle? How long will it take for solar panels to charge a car? How many panels will you need to charge your car in the first place? These are some of the issues Musk hopes to solve with one all-encompassing mega brand. Now that Tesla has been unquestionably established as a clean energy behemoth for the future, it’s time to explain what this all means for the carbon-conscious homeowner in a world where going solar or going electric has been merged into a more Musk-approved, illustrious phrase of “going zero” (emissions).
How many kWh does it take to charge a Tesla Model S?
In order to understand how solar panels and Tesla vehicles complement each other in Musk’s vision, we first need to understand how electric cars are charged rather than fueled. And because solar panel systems are sized based on the expected energy usage of a household, a homeowner would need to take into account projected energy needs from his or her Tesla in order to get a solar panel system that can generate enough electricity enough to meet that combined demand.
The cross-functional metric to use here is kilowatt-hours (kWh), which represents the amount of energy used while kW would refer to available capacity. In order to compare electric vehicles (EVs) to automobiles, the EPA uses the amount of kilowatt-hours required for an EV to travel 100 miles as a miles per gallon equivalent (MPGe).
According to FuelEconomy.gov, the 2018 Tesla Model S Standard Range requires about 31 kWh per every 100 miles, giving it a fuel economy rating of 109 MPGe (combined city and highway). Thus, if the ultimate question is how many kWh it will take to charge your Tesla, it will depend on the distance you plan to travel. A short trip 25 miles each way would require roughly 17 kWh of energy, while the energy needed to run errands around town might only require 2 or 3 kWh.
How many solar panels does it take to charge a Tesla?
Now that it’s clear how much energy a Tesla vehicle will require, the next step is to calculate how many solar panels are required to provide that charge and fulfill the Musk doctrine of going completely zero emissions in one fell swoop. Because solar panel electricity production is dependent on a few different factors, we’ll use an example homeowner who already has solar but wants to know how many more panels it will take to supply energy for a Tesla Model S. Let’s call her Barb.
Barb has a 5 kW (5,000 watt) solar system, the average system size for the U.S. residential solar market. She lives in Cleveland, Ohio where solar is not unusually cheap or particularly expensive. In Cleveland, the average annual energy production for 5kW solar systems is 6,071 kWh, which means that every year Barb’s solar panels are producing that much energy. Assuming Barb’s system uses standard 250-watt panels, we then also know that Barb’s current solar array has 20 solar panels (250 W x 20 panels = 5,000 W). This means that each of Barb’s panels produces just over 303 kWh of energy in a year (6,071 kWh/20 panels). Let’s think of this number as Barb’s annual energy production for a single panel.
How much will it cost to charge a Tesla with solar panels?
As we learned above, Barb’s new Tesla Model S has a 31 kWh/109 MPGe rating. If we assume she will be driving 25 miles a day, we then know her Tesla is going to be using 7.75 kWh a day (about 2,829 kWh per year). Then – stay with me here – we can use our prior annual energy production value of 303 kWh/year and determine that Barb will need to add roughly 9 more solar panels to her system in order to completely cover her new Tesla and receive the seal of zero emissions approval from Mr. Musk.
The next question might be “how much does it cost to charge a Tesla with solar” or in other words, how much extra will Barb need to pay for those 10 panels. If we assume an average price for a standard panel is $185, charging Barb’s brand-new Model S will likely tack on another $1,665 to her solar panel system costs. Compare that to total money spent at the gas pump every year and we start to see why pairing a Tesla with solar panels makes sense. In the long run, Barb will see concrete energy savings on multiple fronts, and will likely break even on her solar panel investment in seven to 10 years.
Tesla solar charging stations and Tesla Powerwall
If you’ve been following Tesla for some time, the acquisition of SolarCity should not have come as a shock. Tesla car charging ports with overhead solar canopies (as seen in the image above) have become a common sight in Europe and America, and the Tesla Powerwall is really the only solar battery brand that homeowners can cite by name. The Powerwall has seen numerous hurdles and criticism. However, Tesla successfully got the attention of mass consumer markets in bringing to light the benefits of solar-plus-storage as a highly efficient alternative energy solution. Tesla now needs only to sit and wait while its brand blows past the competition.
Out of Musk’s “Masterplan Part Deux” came a plan for Tesla to launch other electric vehicle models, including trucks and minivans, as well as a clean energy rideshare offering. We can expect the number of solar-powered charging ports to explode in the coming years. Even now, you can purchase Tesla branded wall-mounted charging stations for your home – an option that is sure to become more popular as the Tesla Model 3 hits the road across the country. These sleek, all-renewable power stations are a visual representation of Tesla’s mission as a corporation and their role will see dynamic value under the new era of Tesla.
In a sense, the merger is just an upgrade of prior solar projects that Tesla flirted with in order to brand itself as a renewable energy company rather than a car company. The groundwork has long been in place for Musk’s clean energy integration – with the Powerwall, electric cars, and images of Tesla’s new, rebranded solar panel design already surfacing online, Tesla is fully and openly bringing its sleek, luxurious touch to the solar industry. While many were surprised by the acquisition, some are wondering why it took so long. Those same people might also be anticipating the day when “Musk” is officially deemed a synonym for the word “innovation” in the English language.
How to find the best deal on solar
For those planning to go all in on clean energy, hopefully this breakdown helped you to envision the integration of solar and EVs. The next step towards zero emissions is to begin searching for the right EV and start comparing quotes for a solar panel system. The EnergySage Solar Marketplace allows you to compare real pricing data from homeowners in your area and review various financing options for free. For those looking for a personalized instant estimate for solar, try our Solar Calculator (recently recommended by Consumer Reports).