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Comment by spywaregorilla | Hacker News Reader

> The car also boasts a “safety cell seven times stronger than steel,” for those worried that its unique design may not hold up well in an accident

Isn't that the opposite of what you want? Like... crumple zones?

> there’s also an option to put extra panels on the hood and hatch to add range

Sounds dubious. Can't imagine you're getting much power from an extra panel on the hood over the course of a drive?

Website also states that me, living in boston, driving 40 miles a day would only need to charge 6 times a year? There's just no way that's accurate. Deeply skeptical of this one.

Though I wouldn't hate a 20k electric triwheel car that didn't try to force the solar gimmick.

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> Can't imagine you're getting much power from an extra panel on the hood over the course of a drive?

It's not just over the course of a drive. It's charging while your car is parked out in the sun all day long.

> Website also states that me, living in boston, driving 40 miles a day would only need to charge 6 times a year? There's just no way that's accurate.

Back of the envelope, that seems reasonable enough:

700 W * 12 hours/day * 2/pi (to account for sun angle over the course of the day) = ~5.4kWh/day.

Cut that in half to account for lousy Boston weather, and you get 2.7 kWh/day.

If they can get 10 mi/kWh (a Tesla gets ~4 mi/kWh), then that's 27 miles/day, which leaves you 13 miles/day short. Their battery provides 1000 miles of range, so you'd need to charge every 76 days, or about 5 times per year.

That still seems optimistic to me. These are non articulated panels, so I'd expect to see decent charging rates around local solar noon, but steep drop offs before and after, not to mention that any part of the panel being in shade will totally kill the efficiency.

There is no way that rooftop area is even as large as a standard solar panel (say 200 ft²). Even the most efficient panel is no more than 350W, so you're cutting your "700 W" more than in half right off the bat. Discounting less efficient cells, road dirt, and non-perpendicular angles and we'll be generous and say 300 W.

12 hours/day is the maximum possible solar duration so you really need to cut that in half to account for a full year on Earth. So we're down to 1 kWh/day and realistically much less if you happen to park under a tree or a bird poops on your roof. That will hopefully get you to a charging station but not much further.

The 700W number comes from Aptera's website [1]. You don't have to believe them -- but to achieve that, they'd need about 3.5 square meters of solar panels, and if you look at the overhead picture on that page, it looks like it has about that much.

12 hours/day is the average solar duration. You'll get more than 12 hours of sunlight in the summer and less in the winter, but it'll average out.

And sure, if you park under a tree or let your panels get dirty, you'll reduce the amount of charge you can get. Same thing if you park in a garage or paint the roof. We can sit around all day and come up with ways to kill the performance. But you can just choose not to do these things.

[1] https://aptera.us/vehicle/

They sound great for shared cars by the hour.

Kinda think govs should mandate one per suburb street to give people a mobility option, especially when they don’t require full licence.

Or we could just design cities that didn’t require cars.

I wish but it’s too late. All the cities (at least in the States) being designed now are sub/exerbs.

I thought this too until I heard about Amsterdam. Apparently it used to be car-centric as well. Then they decided whenever they were going to re-do some district, they would re-do it as walkable. Sure, it takes 40 years, but it's possible.

Sure, lets compare $25k solution vs trillions of dollars...

One issue is that much of the above is about ideal conditions. One has to think about the average car owner.

Even IC engines have ideal conditions like don’t use a lead foot and light on the brakes, but the average driver isn’t getting the ideal MPG. Similar issue with solar.

I think Aptera isn't intended for the average car owner. It's for someone who wants a specific type of performance, likely an enthusiast.

There's several square meters on there, and they could be using high efficiency panels.

700W is perfectly reasonable. I have a 200W panel acting as shade over a tricycle which is much smaller and can easily charge a 1kWh battery in a day..

> It's not just over the course of a drive. It's charging while your car is parked out in the sun all day long.

I know this is pedantic, but it said extra RANGE. Range to me asks how far can you go without stopping.

> Cut that in half to account for lousy Boston weather, and you get 2.7 kWh/day.

But if you have a lousy day you need to charge... you can't take a battery deficit and make up for it later with a reversion to the mean.

> you can't take a battery deficit and make up for it later with a reversion to the mean.

Sure you can. Let's say you have a lousy day where you get 30% of the peak power (1.6 kWh in the example). You'll use 2.4 kWh of battery power that day, and unless your battery was already extremely low, you won't need to charge (and even if you do have to charge, it won't affect total charges per year - see below).

If the next day is good weather and you get 70% of peak power (3.8 kWh), you'll only use 0.2 kWh that day. Overall, you've driven 2 days and used 2.6kWh of battery power. Which is exactly the same as if both days had delivered 50% of the peak power.

Even if you assume that the entire winter will be lousy and the entire summer will be nice, that just means your charging schedule will be different based on season - you might need to charge every 50 days in the winter and every 120 days in the summer - but you'll still end up with the same number of charges per year.

But it's a queuing theory problem. The average is not a good indicator. It's how often does it reach a level that is so low you need to charge. Not the averages of the system. And it's not 0%. It's a level low enough that you don't want to bet on the charge rates

> Sounds dubious. Can't imagine you're getting much power from an extra panel on the hood over the course of a drive?

It's not primarily about charging while driving, it's increasing the range added from charge time while parked under the sun. Think parked all day while at work. It will increase the range of your commute to/from work, assuming it can charge in sunlight throughout the workday.

> assuming it can charge in sunlight throughout the workday.

That seems like a very bad assumption to me.

It seems like a perfectly reasonable assumption. The vast majority of parking spaces in existence are uncovered. And in cases where covered parking exists, there are usually uncovered options (for example in most parking garages that have a top uncovered floor, that floor tends to be the least occupied).

I was more referring to weather.

I love the idea of this vehicle, and if it performs as advertised I could see myself using it. However - I wouldn't want to bank on it charging during work to extend it's range every single workday. Overcast and rainy days happen almost everywhere, at least some times.

Or I could be misunderstanding something about solar panels - do they continue to charge even without direct visible light? I don't know much about them.

> Or I could be misunderstanding something about solar panels - do they continue to charge even without direct visible light? I don't know much about them.

They diminish output in proportion to the amount of light. In a charging situation where you require at least a certain voltage to push anything into the batteries, I presume it will just stop charging well before the panels are 100% dark.

Their calculations include corrections for capacity factors due to weather. They are probahly a little generous about traffic conditions in some areas though. 40 miles at constant 30mph is very different to stop start hitting 30mph each block or to constant 70mph.

A 100kWh battery is sufficient to average available energy for a 700W panel out over several weeks in summer at lower latitudes, and a month or so in worse conditions.

The idea seems untenable until you consider that it's more like a big ebike than a car. It weighs a fifth as much as a tesla and has under a third of the air resistance.

Solar panels don't care which direction the photons arrive from; they work fine in overcast conditions.

>fine

They are much less efficient however

Solar panels do produce less power on overcast days than in full sun, but they are actually more efficient, not less - like other semiconductors, they work better at lower temperatures.

Interesting! Thank you!

On one hand, I see where you are coming from. The vast majority of people overestimate the ability of solar to generate power. It requires a lot of surface area with good orientation to generate "meaningful" power, where "meaningful" is enough to power a typical house, a typical car, etc...

But it is also possible to attack the problem from the other end. Instead of making more energy, make things more efficient. For example, my e-bike is incredibly efficient. A 100 watt solar panel with good orientation and exposure is likely sufficient to charge my e-bike for my (previous) 14 mile round trip commute (since covid I am WFH though). But that same panel would probably get you 1-2 miles in a Tesla (more likely 0 as you couldn't even push enough power to initiate a charge on the massive batteries).

Seems like Aptera is coming at this from the efficiency end. There is an annual collegiate solar car competition and based on previous results you can get a pretty good upper bound of how many miles a "car-like" machine can travel on solar alone[1]. Based on those numbers, it looks like the multi occupant vehicles can get into the 80 miles per day range. This is on a track, going ~30 mph, so definitely not real world conditions. But one doesn't have to stretch their imagination too far to see how adding a few more creature comforts (i.e. vehicle weight, cabin and trunk space) and taking into account real world driving conditions, but also investing more time in aerodynamics and solar panels (the college kids in the solar comp are on a much lower budget) could result in a 40 mile/day estimate. I would probably guess that is on the high side, as Aptera has an incentive to push the numbers in their favor. But I couldn't certainly see how the numbers could be possible.

Aptera has a somewhat checkered history, which is another issue entirely. But just from a quick gut check, nothing they are promising seems to be out right impossible.

[1] https://www.americansolarchallenge.org/the-competition/2021-...

I think it goes without saying that this vehicle isn't a perfect fit for every situation.

It'd suit the vast majority of commuters by me (American southwest), assuming it performs as advertised - which may be another very bad assumption.

These 3-wheeled "legally a motorbike" car things are always an unpopular niche. Fantastic efficiency and a low price, but most people would rather shell out for a full-sized car.

They're legally motorbikes, so they are often not as safe as cars. This one boasts "eggshell" composites for crash safety, but often the lack of mass makes it hard to make these as safe as a heavier vehicle.

2 seats. It seems to have a lot of storage (25 cubic feet) but I bet it handles very badly if it's weighed down.

I can't find any mention of performance. I bet it's relying a lot on the high low-end torque of electric motors, and aerodynamic design at high speeds, and I wouldn't be surprised if it still handles quite slowly. I found a claim somewhere that it's over 99mph, which isn't exactly stunning.

There's already plenty of 3-wheeled EVs, the SARIT, ElectraMeccanica Solo, Spirtus EV as well as this one - https://electricautonomy.ca/2021/05/10/electric-three-wheele...

These things never do that well. It's not because they're a terrible idea, they just have a lot of compromises. Of course, if conventional cars are too expensive (either the high upfront cost of an EV, or the high running costs of a gas guzzler) then it does make them a little more attractive.

Every time gas goes up, you see a bunch of people driving motorbikes or scooters to work to save money. Something that's legally a scooter but has a nice canopy could make a bit more sense, but it rarely seems to catch on.

Where I live, having a license to drive a car doesn't give you a license to ride a motorcycle. You have to go through whole stages of training/certification.

That's the same where I live, but there are plenty of motorcycle learn-to-ride classes that cost maybe $200 and provide the motorcycle. On the last day of the course, a person from the state comes by, supervises the testing, and (if you pass) signs the paperwork to get your license.

It's about as easy as it can be; if you want this Aptera thing a motorcycle license is not a barrier.

What concerns me more is that they have their factory in Carlsbad, CA. I don't think there are too many worse places to put a factory if you have a price point to meet, and I doubt that there is any space to expand.

It's a bit harder here, since you go through several stages, firstly a "learner license", with an "L" plate on the vehicle, then a "provisional license", with a "P" plate, before getting a full license. I think it's a somewhat expensive and time-consuming process.

I haven't done it that way personally, I got a car drivers license decades ago, when it was easy, and swapped it every time I moved countries. Getting a new license for a motorcycle isn't very appealing.

The battery adds a lot of weight so thing thing is heavier than a gas powered trike. I believe 1800lbs for the base model and 2500lbs for the longest range one.

Re: crumple zones. I believe Smart cars feature a similar concept, most of the car is sacrificed on impact—the whole vehicle is a crumple zone—except the the two seats embedded in a tiny roll cage

My electrician friend just told me the other day that the sun very conveniently produces a 1000w/square meter at high noon. Solar panels have an efficiency of around 20% give or take. That is in direct sunlight at high noon. So at peak time of day you can produce about 200w/square meter of solar panel. That’s not a whole lot of energy so adding extra panel to the hood won’t yield a lot of energy but I guess every bit helps.

> Isn't that the opposite of what you want? Like... crumple zones?

Well, no. You have those zones + extremely strong cell. [0]

https://youtu.be/TJzZ7-Od6KY

> Isn't that the opposite of what you want? Like... crumple zones?

If its the same design as the original failed aptera the shell is carbon fiber.

There is a big question as to who is funding them as the original aptera motors had the same design & went bankrupt in 2011.

Yeah, that's nonsense.

Because of the downvotes I will explain my statement.

The car has "a safety cell 7 times stronger than steel". That makes no sense. The strength of a physical object is a combination of the strength of its material(s), the geometry it's made into, and the joining method used to connect the parts.

An object is not stronger than steel, a material is. Saying an object is stronger than steel means nothing.

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