When humans approach the end of this century and look back, they will probably count solar power and electric mobility among the most groundbreaking changes of this century. Both technologies have tremendous potential to save money, and can play a pivotal role in slowing down climate change.
While both solar panels and electric cars are game-changing technologies, the most brilliant thing to do is combine both of them. Let us take a look at how solar panels can power electric cars (EV), and what are the benefits of doing so.
Can I Charge An EV With Solar?
Our universe is a beautiful contraption of different forms of energy. Whether it is petrol, sunlight, electricity or the movement of a car - all are different forms of energy. Theoretically, any energy can be converted into any other form of energy. And the current state of solar power is sophisticated enough to easily convert sunlight into electricity, which can then charge the battery of an EV.
Light from the sun contains photons, which excite and move free electrons in a photovoltaic solar panel, which then generate current. This current can be used to power everything from a TV to an electric vehicle. The only thing you’ll need is a charging system that supports this, as we’ll see in one of the further sections.
For now, let’s go back to the main question of why solar and EVs are such a wonderful combination.
Benefits of Using an EV and Solar Combination
Solar Power is Much Cheaper Than Grid Power
Ranging from 30 cents to 43 cents per kWh, New Zealand has some of the highest electricity rates in the world. Buying an electric car may save you some money on petrol, but your power bills are bound to go up. Consider the Tesla Model Y, which was the top-selling EV of 2022. The basic Model Y has a battery bank of 60 kWh. Assuming that a user needs to fully charge the car twice every month, the added 120 kWh will cost an extra $50 per month.
Naturally, $50 per month is lower than most car owners spend on petrol. But consider a timeline of 25 years, and the cumulative expenditure on electricity becomes $15,000. Interestingly, this is lower than or near the average cost of solar in New Zealand. And for this cost, solar panels can not only power your EV, but also your entire home, which is a win-win! Here is a graphical representation of how cheap or expensive it is to use a car powered with solar, grid power, or petrol.
Here’s another way to look at this - a typical solar power system has a payback period of around 10 years and a minimum lifespan of 25 years. This means homeowners can enjoy free solar power for 15 or more years. Now imagine having a car that requires no fuel costs for at least 15 years. Exciting, right?
Solar Power is Cleaner Than Grid Power
Skeptics of electric mobility usually highlight the one limitation of electric cars - most of them still use conventional, grid power to charge the batteries. While it is proven that electric cars are cleaner than cars with combustion engines, using EVs with solar panels is the ultimate green combination.
In Aotearoa New Zealand, the CO2 emitted by a kWh of conventional grid power is around 150 grams. This may not sound like much, but combine the millions of kWh used by the existing as well as upcoming tens of thousands of electric cars, and you have tonnes and tonnes of greenhouse gases getting stuffed into our atmosphere, worsening the climate crisis. Additionally, as more homes and cars switch to solar, it can also help NZ achieve its target of net-zero carbon by 2050.
Grid And Petrol Prices Keep Climbing
High prices aren’t the only issue with petrol or grid power - the prices of these commodities keep on climbing year after year. In 1991, the price of a litre of petrol in NZ was $1.37. Today, this has crossed the $3 mark. The same is true for grid power. On average, the cost of electricity increases by 3% every year in the country. Over two to three decades, this would mean a substantial cumulative increase.
Solar power, on the other hand, has just an initial investment, after which there are no recurring costs. The sun has never sent a letter to solar homes notifying them of a price hike owing to infrastructure upgrades. And since technically there is no “price per kWh” associated with solar, there is no question of a price hike (yes, we mean free energy!).
Cost savings and environmental impact aren’t the only benefits of powering your EV with solar. For instance, your electric car can double as a battery bank for your house during a blackout. Numerous EV charging brands are offering or working on a smart charger that allows such a capability, such as the Enphase bidirectional charger. Some modern EVs also have this as a built-in feature, like the Ford F-150 Lightning.
Homeowners who already have a solar panel system can benefit highly by getting an electric car. The NZ Transport Agency currently also offers a ‘Clean Car Discount’, which can slash the price of an EV by up to $7,015. Here’s a chart that shows a spectrum of different vehicles as per CO2 emissions and the available rebate or fee.
Lastly, solar panels are also known to increase home value. So if you have an EV but are on the fence about solar because you may not live in that house for three more decades, that isn’t much of a problem, since the solar power system will boost the price of your home. What’s more? Existing EV owners may also prefer to buy your home, typically for a higher price, thanks to all the benefits listed above.
How Many Solar Panels Do I Need To Charge An EV?
If you are charging an EV with your solar power system, you have to ensure that you have enough panels to provide energy to both your EV as well as your home appliances. The size of a solar system required to charge your EV depends on how many kWh your EV draws from the system, which in turn depends on how much distance you drive.
But for the sake of a general example, let us go back to the Tesla Model Y. Let’s say you drive 30 km every day. The base version of the Model Y has a range of 455 km for its 60 kWh battery, which means each kWh offers a 7.5 km driving distance. Therefore, for the 30 km, you would need 4 kWh of energy every day. An ideal, North-facing roof generates 4 kWh of energy for every kW installed.
This means that if you have an EV, you may need to add another kilowatt of solar panels to your system. Assuming the current industry standard of 350-400 W solar panels, you would need three or four extra panels to power your EV. In terms of cost, this would add around $3,000 to the price tag of your solar power system. A one-time $3,000 for zero fuel costs sounds extremely lucrative, doesn’t it?
But these are all numbers based on thumb rules and assumptions, and your case may be different. You may have a more efficient EV, or an East-West facing roof, and the calculations would then be different.
The best way to figure out how many solar panels you’d need to charge your EV is to get free quotes from reliable solar companies in your vicinity.
The combination of solar panels and electric cars seems obvious - even inevitable - with the financial and ecological benefits it offers. In fact, a recent study by Auckland University showed that people with solar panels are more likely to purchase an electric car. Conversely, even though there is no study on this yet, we could safely claim that EV owners are more interested in solar power than owners of fossil-powered cars.
Auckland’s researchers also believe that the New Zealand government can do more to incentivise solar power through promotional programmes and education. But on the ground level, change has already begun. Tauranga already has EV chargers powered by solar panels. Installed in 2017, the charger is called the “Electric Station”, and is a glimpse into what the future might look like.
At the domestic level, the solar and EV combo makes even more sense. It offers free power, virtually free transit, a ready-to-use, integrated battery backup system, and of course, a much-needed lowering of our carbon footprints.