Published on December 12th, 2020 | by Jennifer Sensiba0
Aptera Reveals Solar Calculator
December 12th, 2020 by Jennifer Sensiba
After our deep dive into Aptera’s technologies, one of the questions I kept getting from readers was how much of a charge they can really expect from the Aptera’s solar cells. Aptera calls the charging system “Never Charge,” but it was clear from the get-go that they really meant “almost never charge.” Anyone familiar with solar technology knows that solar cells will produce a lot more power in dry, sunny regions than in cloudy northern areas, so more information is going to be needed.
Aptera came through and gave everyone a useful tool to help answer this question, even if it is a little simplistic.
For example, I put in that I live in Sun Zone 8, and drive 40 miles per day. The tool estimates that I’d need to charge 4-5 times per year to always get where I’m going. At first, this might seem impossible, because the car only is supposed to produce 40 miles worth of charge (per the marketing), so I’d always need to charge a little bit daily, right? The reason Aptera’s thinking works is the battery. With 250, 400, 600, or 1000 miles of range, you get “rollover miles” whenever you get more charge than you need. I’m assuming that days that one doesn’t drive (weekends, mostly), you get the whole 40 miles stored in the battery. Only when there are periods of extended cloudiness or during the shortest days of the year would one need to charge for planned driving.
Here’s what it looks like for Zone 2 with 40 miles per day. Much of Canada and New England falls in this category, as does much of Europe. In that climate, Aptera estimates that one would need to charge around 6 times per year. The same assumptions above likely apply.
For Those Wanting More Information
I know that many of our readers want more information, and it’s actually possible to derive more from Aptera’s sun chart if you know two pieces of information:
- Aptera rates its solar cells at 700 watts.
- Aptera assumes the vehicle will get 10 miles per kWh.
The rest is mostly simple math.
For my Zone 8 example, Aptera’s chart says I’ll get 16.5 to 40.3 miles/day added. To convert to kWh, divide by ten. That means they assume I’ll get between 1.6 and 4 kWh added to the battery daily. Divide that higher estimate (equivalent to 4000 watt-hours) by 700 watts, and it comes out to almost 6 hours of full light. Assuming around 10 hours of actual light, that actually makes sense because you don’t get full solar output in the morning and evening. 700 watts is just the peak output around noon.
So far, Aptera’s numbers check out.
Now, let’s check the estimate of how often one might need to top the battery up from the grid. If each week one gets 28 kWh added (4 kWh x 7 days), and you drive off 20 kWh during the week (keeping 8 kWh extra from the weekend), then you end up with extra added on the best weeks. On the worst weeks, you add 11.2 kWh while still using 20 kWh, which means you’d run a deficit of almost 9 kWh. Spring and fall would end up landing at about break-even, with summer having not quite enough to cover the winter. That’s probably where most of the charging would happen, in the winter.
During the winter, the deficit of 9 kWh would eat through a 100 kWh battery in about 11 weeks, leaving a lot of time between the need to charge. Throw in some cloudy days, and Aptera’s estimate of charging 4 times a year seems quite reasonable. I would very unlikely need to even bother with level 2 charging.
The numbers in your area probably differ from mine, so you’ll definitely want to run them for yourself if you need that information.
Let’s Get More Realistic
Here’s the thing, though: Life is always throwing us curveballs. Nobody is going to spend 11 weeks watching the needle slowly approach empty. One would likely want to keep an extra half battery or so ready in case you have to take a trip on short notice or have way more extra errands to run some day than normal. You can also count on doing driving on the weekends, which cuts into the surplus.
None of that really kills the idea of Aptera ownership, though. Even if you had to charge 52 times a year to do all that, you’d add 120-150 miles while sleeping one night a week from a normal wall plug, which would make it easy to keep up a few hundred miles of range for the unexpected.
If you feel I’ve helped you better understand Aptera, feel free to use this link to reserve yours. You get $30 off your preorder, and we get points toward getting our own Aptera test vehicle. Expect detailed testing once they roll out!
Sign up for our free daily newsletter to never miss a story.
Have a tip for CleanTechnica, want to advertise, or want to suggest a guest for our CleanTech Talk podcast? Contact us here.