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Solar panels on cars make no sense at this point

101 points by elorant 4y ago

bilsbie 4y ago
I agree but not completely. People seem to do the math and get maybe 5-10 miles of range per day. I’d say that actually quite useful. Especially if you only drive around town or leave your car for days at a time. Or imagine running out of battery in the middle of nowhere with no phone reception. Just wait a day and keep driving to a better spot. That’s really useful. Finally this ignores the idea of having panels that fold out when you park. You could easily 4x your solar collecting area and get some real range.
- sclarisse 4y ago
  Does it often happen that the typical driver of a car is somewhere in the middle of nowhere, with no cell reception? If not, it seems of limited usefulness.
  - bilsbie 4y ago
    Cell phone reception is actually pretty spotty once you leave urban areas. So it could be more frequent than you’d think. And beyond that it’s harder to call for a charge up than for a can of gas. So options might also be limited.
- tomrod 4y ago
  5 - 10 miles per day of sunshine = 1200 to 2400 miles in high sunny place, 600 to 1200 miles in low sunny place (speculating). Not bad value add.
  - AdrianB1 4y ago
    Bad value versus what? If you invest the same money in a stationary PV grid at home, it is a much better value, that is the point of the article. As I have a PV grid at home I mostly agree with that.
    - tomrod 4y ago
      Nice, I like when people add home PV. Is it always an either/or decision then?
      - AdrianB1 4y ago
        From an economic and environmental perspective home PV make sense (but the investment takes many years to recover), on cars not at this point, maybe in the future. The article describes options less than 1 KW, at home you put 5-20KW, it's a very different kind of beast.
        steveBK123 4y ago
        Yes, and people don't understand that EVs actually use quite a lot of power relative to a freestanding home. If your home uses gas/oil for heat & hot water, you might only use, say 20kWh/day in winter and 35kWh/day in summer. This matches pretty well with the amount of solar generation you can put on your roof! The cool thing too is that you get more sun in summer, when it is hotter.. and you use more electricity because of the AC.. so it matches pretty well! Now that same 20KwH in winter is enough to fill 20-30% of your battery of your EV to drive 60-80mi. Your little car roof will generate minuscule amounts of power by comparison to your entire homes roof, while also being at the wrong angle, sometimes parked indoors or in shade, or in motion & not charging during daylight hours.
    - Forge36 4y ago
      35% of people do not own a home. This could be a reasonable middle ground. It's not as efficient as a home system, and it doesn't need to be
- steveBK123 4y ago
  You've just added a motor, a wear&tear item, another $1000 in cost to the panels by adding the folding mechanism. Don't forget some sensors to ensure the car can't be put into drive while panels are folded out. How much charging time gets consumed back by the panel fold in/out movement? Does the car now need an interface to allow the user to select when to fold out (long planned parking only?). This is not set-it-and-forget-it convenience.
- myself248 4y ago
  Yeah, 5 miles a day would cover 99% of my driving lately. When the Aptera announcement came out, I analyzed my fuel receipts, and concluded that I would plug the car in 2-3x a year (occasionally I find myself in Chicago or other day-trips), but the rest of the time solar would more than cover my usage. And that's assuming some hefty derating for latitude, cloudy weather, etc. I just don't drive that much, but when I do, it's places and times that aren't well served by transit so I very much need a car. If I go back to working at the office and solar only covers a portion of my driving, that would still likely mean plugging in once a month instead of once a week without the solar, which is still pretty cool. I think this article is "it's not a 100% solution so therefore it's a 0% solution", which is a pretty tired tactic at this point.
  - steveBK123 4y ago
    The number of people who need a car and drive less than 5 miles a day is a small circle. Have you considered walking, biking, or an e-bike? It's recommended that people walk about 5mi/day anyway..
    - myself248 4y ago
      I hadn't considered walking, never heard of it actually. Thanks, let me look that up!
      - steveBK123 4y ago
        It's pretty good, but big tech/auto doesn't want you to know this one trick!
    - ramesh31 4y ago
      >Have you considered walking, biking, or an e-bike? It's recommended that people walk about 5mi/day anyway.. This comes up every time, and it's simply not an option for the vast majority of the US population.
      - steveBK123 4y ago
- driverdan 4y ago
  Because the math doesn't make sense. The added weight, build cost, and complexity make it less value than plugging in. Your "running out of battery in the middle of nowhere" scenario doesn't make sense. If you're that close to help you can walk there in less time than it'd take to charge the car.
- pornel 4y ago
  This stranded scenario is a such solution in search of a problem. The charge rate is slower than walking speed, and 5-10 miles is an easy walk (likely preferable to spending whole day roasting in a car without A/C). Besides, EVs don't suddenly run out of battery like you imagine. Batteries display state of charge very accurately, so you'd know way ahead of time if you shouldn't be heading towards middle-of-nowhere. But even then, EVs don't run out of battery suddenly, but gradually lose power and get slower. To get stranded, you'd have to be a fool ignoring all predictions, satnav, and then stubbornly drive slower and slower for 20+ miles while all the warnings are beeping at you.
t344344 4y ago
Solar panels make great sense on ICE vehicles. Trickle charge from small solar panel may preserve internal battery much better. And there are RVs. Some people use solar panels on cars as their only source of electricity!
- AdrianB1 4y ago
  RV and sailing boats have a relatively large area that can be used for panels. Small installations (less than a couple of kW) have a low efficiency, the inverter and storage losses benefit of scale are lost.
- steveBK123 4y ago
  RVs are by their nature stationary for long periods of time, and the RV are using the solar to power appliances & creature comforts inside.. which is rounding error next to moving a multi-ton vehicle.
  - t344344 4y ago
    What is your point? Article says that it "makes no sense", I provided two counter examples. ICE cars also have batteries, if that gets flat, car is not going anywhere. Solar panels can be quite essential, if vehicle is parked for extended periods. It is not just some rounding error!
    - steveBK123 4y ago
      RVs also generally have spare tires, fridges, microwaves and beds! Why doesn't my sedan? Tesla needs to release a Model S with a microwave, fridge, spare tire and bed!
      - t344344 4y ago
        Again! Trickle charge from solar panel extends battery life of internal (part of ICE) lead battery. This battery slowly discharges from internal resistance, other electronics (car alarm), GPS spyware... That means less batteries, less lead in nature, more green stuff, happy Gaia... And even EVs like Tesla has slow discharge. It makes sense to put small solar panels on top, so they can do firmware updates. https://hackaday.com/2020/03/10/solar-panel-keeps-car-battery-topped-off-through-obd-ii-port/ https://hackaday.com/2020/03/10/solar-panel-keeps-car-batter...
wazoox 4y ago
This article is thin on content and wrong on many many points. 1° the Lightyear Zero is actually in production. There is no reason to think the cars built won't be sold soon... 2° the lightyear 0 has a sophisticated series of controllers for its solar cell that can activate solar cells independantly, therefore it's definitely no losing 50% of its power when 5% of the panel is in the shade. 3° dust doesn't reduce solar output that much. Washing the panels once a year is generally enough, and most people wash their cars more often than that. I love back-of-envelope calculations to check for lies, but they shouldn't preclude making your minimal homework first...
- moffkalast 4y ago
  > sophisticated series of controllers for its solar cell that can activate solar cells independently, therefore it's definitely no losing 50% of its power when 5% of the panel is in the shade Aka just putting a single bypass diode on every cell, it's not complicated.
- bouk 4y ago
  Lightyear zero is no longer in production: https://lightyear.one/articles/lightyear-decides-to-fully-focus-on-lightyear-2 https://lightyear.one/articles/lightyear-decides-to-fully-fo... And it seems like the whole company might be bankrupt.
- mikestew 4y ago
  the lightyear 0 has a sophisticated series of controllers… It was an extra $50 to get a controller for our RV solar that has that same functionality. MPPT solar chargers are hardly “sophisticated“ anymore. Speaking of chiding others for doing homework, the Lightyear is no longer in production: https://techcrunch.com/2023/01/23/lightyear-stops-production-on-e250000-solar-powered-ev/ https://techcrunch.com/2023/01/23/lightyear-stops-production...
- jillesvangurp 4y ago
  Aptera is also close to production. Several other, manufacturers are adding solar to their vehicles. Also, there are a few electrical campers with some solar panels. So, basically these things are coming to market. And why not, it makes a lot of sense. Most cars don't drive most of the time. And if they are catching any light, you basically top up the battery a little bit for free. Or put differently, that's energy you don't have to pay for. Yes, it adds some cost. And it saves you money. Kind of balances things out pretty quickly. And it adds some convenience for day to day use where you add enough power that you don't have to go to a charger so often. Especially for short commutes, this makes a lot of sense. Dust is not a big deal. Indeed nothing a good old car wash can deal with. Or a bit of rain. Panel degradation happens very slowly otherwise. I don't think that's a huge concern.
steveBK123 4y ago
Yes. This pops up on EV forums/reddit regularly "hey why don't we just put the solar panels on the car". It's a bearish indicator when any EV startup pumps a new prototype where this is a key feature. Short version: adds weight and maybe $2000 manufacturing cost to the car. Best case current tech it maybe adds $50/year of electricity to your car, requiring you to park outdoors, in good FULL sun, in parts of the world that get a lot of sun-hours-per-year. Further solar roof of a car is not at the idea angle that a home roof is. Remember while you are parking your car in said parking spots you are also baking the insides so in weather above say 55F, it will get quite hot and probably need to turn on the HVAC systems to cool the cabin and/or battery periodically.. wiping out some of your solar charging gains. Aesthetically, tt replaces the lovely glass roof many EVs have and so makes the experience worse. If you have a garage charger or charger at work, this is rounding error and irrelevant. If you don't and need to fast charge regularly, the fact that your car adds LESS THAN 1kWh/day from solar charging will save you.. 24 seconds of fast charging, per day of solar charging.. lol.
- JKCalhoun 4y ago
  A solar carport sounds ideal. Guessing many HOA's would lose their shit over that though.
  - matthewdgreen 4y ago
    This is the one I want to build (though in a smaller size.) It’s attractive and uses panels directly as the roof. I am debating whether to get into a war with my HOA over it. https://timberhomesllc.com/our-work/outdoor-structures/vermont-solar-carport/ https://timberhomesllc.com/our-work/outdoor-structures/vermo...
    - chipsa 4y ago
      If your state has rules about HOAs not being able to block solar panels, it's probably worth it.
  - Rebelgecko 4y ago
    Those are becoming somewhat common for big parking lots in Southern California, like at schools
GoToRO 4y ago
Tldr if you do everything wrong, like we say you will, then it will not work on some edge cases that we state they are very important for all people at all times.
threeseed 4y ago
> You can build a small installation for your house * 30% of Europeans rent. 50% for Germany. * 46% of Europeans live in apartments. 63% for South Korea. It reminds me of the whole "just install a charger at home" argument. It simply isn't an option for a large percentage of the world and alternatives will be needed. Solar cars may have some impractical elements but at least it's workable.
- andrepd 4y ago
  If they live in an apartment in a dense city then EVs aren't the solution anyways: e-bikes and public transport are, not clogging the city with electric SUVs transporting mostly one person at a time.
  - threeseed 4y ago
    So all of Europe, South Korea etc are going to abandon their cars in favour of public transport and e-bikes. And this hasn't happened already because ..
    - GaggiX 4y ago
      If you live in an European city you are probably already using the public transportation, plus cities are now full of e-bikes and e-scooters, this was not true until a few years ago, so yes, it is already happening, particularly for the 46% of Europeans you mentioned earlier.
      - threeseed 4y ago
        Europe is a $413.50bn car market [1] I am going to take an educated guess that your views do not align with the majority of Europeans. [1] https://www.statista.com/outlook/mmo/passenger-cars/europe https://www.statista.com/outlook/mmo/passenger-cars/europe
        xxs 4y ago
        In most of the EU larger cities is next to impossible to go work by car. If the office is outside the city and it has a large parking area - yes, but that's quite unlikely.
sollewitt 4y ago
There's the benefit of figuring out mass market car integration. It may be we have to rethink what a car is - competitions like the American Solar Challenge show you can run minimal cars for thousands of miles on solar: https://www.americansolarchallenge.org/ https://www.americansolarchallenge.org/ - which is great, but they will never address mass market industrial engineering.
bilsbie 4y ago
How come no one is building a portable EV Charging kit with a bunch of panels you can spread around the area. Maybe in the 1000-4000$ range. It’s strange there’s nothing in between roof top solar for your whole house and a dinky panel built into your car roof.
- JKCalhoun 4y ago
  I imagine those would get swiped pretty fast.
- driverdan 4y ago
  Because it doesn't make any sense. No one is going to put up and take down a giant solar panel array to charge their car.
  - steveBK123 4y ago
    Yeah but what about a wind vane that deploys from my car roof to re-charge my battery while I am driving? /s Also what about if we also put solar panels in front of the the headlights so we can charge the car in the dark? /s
    - twobitshifter 4y ago
      Wind powered cars are possible and pretty cool. Turbines could use the apparent wind to generate just the same way it’s used by sailboats to go faster than the wind. https://m.youtube.com/watch?v=jyQwgBAaBag https://m.youtube.com/watch?v=jyQwgBAaBag
      - steveBK123 4y ago
        dude I was making jokes about perpetual motion machines
- AdrianB1 4y ago
  They are an electrocution hazard, the voltage on a string of panels is several hundred Volts, enough to die. One can build a fool-proof system, but the current devices and connectors are meant for static configurations handled by a qualified installer. You can DIY, but most people cannot do that safely. Also a 500W panel is ~ 20 KG (~45 pounds) and an MPPT can exceed that weight. For a car with a battery that is tens of KW, any portable system that is less than a few KW is not very useful, charging the car 5% per day is not feasible for most.
Forge36 4y ago
Not everyone parks indoors. Not everyone has reliable access to charging. This could be added to a plug in hybrid (mine only gets 20 miles electric, which covers my summer commute). Should solar panels be added to every electric car? No. Could this be an option for some people to reduce dependency on gas who are otherwise unable? Maybe.
thomaslangston 4y ago
One way to approach the engineering question of how to make solar cars for the mass market is to push the car body design to be extremely efficient. Aptera's three wheel, two seat, design seems more likely to deliver the type of daily range extension that will make solar cars a contender in the market. https://aptera.us/vehicle/ https://aptera.us/vehicle/
- steveBK123 4y ago
  Aptera is not long for this world, especially now that ZIRP is over. Pointing to Aptera as an example of why this is feasible is like pointing go some screen grabs of Duke Nukem Forever in 1999. Solar roof cars are like the Google Glass of EVs.
  - thomaslangston 4y ago
    This doesn't compute. Higher interest rates makes a highly efficient and modestly sized two seater more attractive not less.
    - michaelt 4y ago
      Higher interest rates are good for efficient cars, true. But higher interest rates are bad for startups with no revenue, who rely on venture capital to avoid bankruptcy.
      - throwawaymaths 4y ago
        Depends. There are venture capitalists who are looking at the interest rate shift and claiming they are shifting away from low capex lottery tickets to taking another look at high capex, especially if there are fanatical buyers on the market. That said: 1. VCs say a lot of things, and don't always put their money where they say they do. 2. It's troubling that aptera is going for even more equity crowdfunding, and that they are throwing a lot of their fanatical (first mover) supporters under the bus by preference exclusively to crowdfund investors, it's a sign of desperation.
freitzkriesler 4y ago
Except a Maybach from the 2000s has a PV panel on it for powering the Aircon and built in champagne cooler https://www.autoblog.com/2007/10/19/its-friday-300-000-car-with-solar-panels-in-the-roof/ https://www.autoblog.com/2007/10/19/its-friday-300-000-car-w...? Sure, solar panels on low end EV cars are unnecessary but if I'm paying six figures for a sporty golf cart I want a solar panel to keep the inside cool. Theres a segment of the automobile buying public who will purchase a car with one integrated over others that don't.
tappaseater 4y ago
Even solar panels over a bank of Superchargers is essentially a marketing exercise. An array over a 20 acre parking lot? Now you're talking.
- steveBK123 4y ago
  YES. The benefit of solar canopy over L3 charging station is almost more in the protection from sun & elements than it is the actual electrical generation. A single car parking spot worth of canopy could maybe generate 20kWh per day being very very optimistic... meanwhile L3 charging users pull down 20Kwh in about 8 minutes of charging.
- bertil 4y ago
  I agree that it’s generally not enough, but it feels really well-aligned. It offers shelter, prevents the car from overheating, distributes resiliency where people need it, reduces the dependency on electricity transport infrastructure, answers the annoying question about the fossil-fuel-dependent grid, etc. But I agree: you don’t want just the loading section, but every parking lot to be entirely covered, resting area, play pen and access road too. Mainly because those are available areas that could use the shelter and, if anything, for more marketing: brand the panels to make the fast chargers in the corner of the parking lot that much more apparent. I actually would rather have a (slow) charger at every spot in that lot, to tell all car users: if you had an electric car, you could fill up while you shop. No need for the big fast one. More so: even then, you are still right that we need more. Have agri-voltaic near the fast chargers to show people how those work, or non-polluting industry that need large amount of electricity: Hydrogen generation maybe? It would reduce the dependency on infrastructure. It would be striking to have people take a break from the road near modern installations that demonstrate that we can have less polluting options.
googlryas 4y ago
Hell, solar panels on houses make no sense either - unless you can store/use the power locally(which many houses cannot) and don't have land to put them on the ground. Better to put all of them in a big field. Easier, safer, and cheaper to install and maintain.
- TillE 4y ago
  Right, solar on building roofs is fine and good, it's not nothing, but it's not a serious way to grow renewable energy. It's thinking far too small-scale. If the grid is fully modernized and using 99% renewables, there are very few reasons to want photovoltaic panels on cars. So you focus on what's cheap and scalable.
  - Schroedingersat 4y ago
    Here's one of many reasons: Keep the inside cool if left in the sun without draining the battery.
powerbroker 4y ago
I note that among the costs for the inefficient car+solar combination, that the CO2 emissions just to make the panels, the inverters, the controls, and the assembly are not mentioned. The article does compare the install on a residential roof -- indicating far greater efficiencies are obtained, without the cost of using extra electrons to carry the extra weight of the aforesaid 'extras'. Aptera, has been suggesting this and going bankrupt at least once, while 'trying' to get to mass production. Their delays make Tesla look positively lightning fast (see, Cybertruck).
- steveBK123 4y ago
  Some of these companies going nearly bankrupt before they've even started production is telling. When you are just designing the thing, your costs are basically staff. Now trying to scale production you have all sorts of capital expenses and then operational costs that don't get recouped until you have scaled production enough. Designing a car is not a hurdle. Building a prototype is not a hurdle. Having 20k pre-sales is not a hurdle. Actual serial production in an operational factory able to ship 10k+ year is your first hurdle. Doing the above while selling the cars for enough money to not go bankrupt, while opening some sort of service network for the cars .. is a big hurdle. Getting closer to 100K/year, is the next real hurdle. And being a real big boy automaker in the 1M/year range is
- DennisP 4y ago
  That Aptera that went bankrupt was actually a diesel-electric hybrid, supposed to achieve 300mpg. They had to close shop when they didn't get the funding they needed. The founders went on to other things for a few years. Now they seem to be making pretty solid progress. I don't think putting "trying" in scare quotes is justified; launching a car company isn't an easy task.
DueDilligence 4y ago
.. sounds like fossil fuel propaganda to me .. yawn. next.
rsolva 4y ago
The german company Sion [0] is close to launching a reasonably priced, solar covered car. For me, their open approach is more important than the solar panels. They have a strong commitment to the community and are transparent and publish regular reports and insights to their progress. They also take a open-source aproach to maintenance, basically releasing everything you (or your local repair shop) need to fix things, and they try to choose readily available parts when possible. [0] https://sonomotors.com/ https://sonomotors.com/
- florakel 4y ago
  At this stage it looks very unlikely this car will ever make it to production. They ran out of money and try to save the program through crowdfunding https://electrek.co/2023/01/26/the-future-of-solar-evs-dims/ https://electrek.co/2023/01/26/the-future-of-solar-evs-dims/
- rsolva 4y ago
  Yeah, I know and this was what I most feared would happen as I kept an eye on this project over the years. It was always going to be a long shot, but one worth giving a go.
legulere 4y ago
The article doesn't consider that in a lot of European cities curb-side parking is very common. People have no garage and usually drive very few kilometers.
reeckoh 4y ago
Of course solar panels cannot provide enough power to drive a car for any significant distance, but that doesn't make them useless. I know, because I put solar panels on an ICE car's roof several years ago. They charged a recreation battery in the boot, which I used to charge my phone, headlamp, camp lights, laptop, radio, smaller power bricks... Fantastic for camping, and it lets you jump-start your own car. The article's prices are for first-party solutions; I paid $2/W and it's been zero maintenance over highways, bumpy tracks, heat, car washes, and frost. Using amorphous cells instead of monocrystalline can net you a bit of energy on cloud/rainy days too, even if they are less efficient in bright sunlight. If you have roof rails or a pickup canopy, give it a try. The hardest part is finding a way to get the wires into the interior. Don't forget some soft cushioning washers in the mounting nuts and bolts.
- grecy 4y ago
  I have two 100W panels on top of the Jeep I drove around Africa for three years. They charge a secondary battery and run the fridge, the water pump and UV Filter, camping / interior lights, all my chargers and laptop charging. [1] I also had a 100W Panel on the vehicle I just drove around Australia for 18 months. In both cases, I'd say they were essential [1] theroadchoseme.com/the-jeep
bertil 4y ago
Those articles miss that there are many vehicles, not just individual cars. Some use cases combine well with a vehicle being outside, slow, and not going far. Aptera is an excellent example of a fun vehicle that leverages its aero-dynamism. I’m not sure why the boxer van market isn’t the most obvious candidate, both for delivery companies (extending an otherwise relatively short radius and lowering the cost of battery seem well aligned) and camper-van, where the autonomy sounds worth the cost. Big rigs also feel like the perfect candidate, assuming someone can figure out how to attach panels when the load is detachable. Trains are fantastic options, although not as perfect as having panels along the rails. Airplanes, even more so — although, yes, integrating into the structure isn’t a done deal. Rickshaws are another obvious example: they can run without pedaling if the whole roof is a solar panel. There’s also a more accessible version of a bike for road trips that could leverage the bicycle-with-a-roof format well. Boats are surprisingly appropriate candidates. Leisure boats, in particular, are mainly used when it's sunny. The water offers extensive cooling available. There are electric waterboards that might not have a roof but still have enough surface to be promising—although I think a new format, akin to a wind- or kite-surf, might make more sense. Too much of the logic starts with assuming people are driving a sedan or an SUV. That’s a terrible idea. It already kills millions every year. We can’t let that lack of imagination also kill electrification.
ajross 4y ago
FWIW: on the other hand covering a EV charger spot with solar in a clear environment can almost pay for the net charging done as long as you have a battery local that can buffer.
- dredmorbius 4y ago
  Or just connect that PV array to the overall grid and supply / request surplus / deficit power as needed.
turtlebits 4y ago
Solar panels on cars are fine. The problem is marketing it as some revolutionary feature that differentiates from the rest of EVs, when it should just be a bullet point next to weatherproof floor mats. Perform studies, get real numbers, otherwise, you're just going to get a bunch of disappointed customers. Having to think about where to park my car to maximize my range is only going to add to EV range anxiety (not lessen it) if you don't have a reliable place to charge.
egberts1 4y ago
This solar panels on vehicles would make most sense in Sahara, Gobi, and Outback.
snozolli 4y ago
Panels are installed in locations and at angles to avoid shading as much as possible, but when you have the panel on your car, you have none of that luxury That sounds like a shortcoming of implementation, not proof that the concept is bad. Yes, I'm suggesting that cars with solar panels should have tilting, sun-tracking roofs. Not that it matters. The reason cars do or do not come from the factory with solar roofs is sales. If the market pays for it, it stays. If they don't, then it goes. I've seen countless people pay thousands of dollars for "ground effects" which are nothing but painted plastic glued and/or screwed to the car body, chrome packages, blackout packages, and 'leather' seats that are actually vinyl and less comfortable than cloth. A significant portion of the automotive market is driven by aesthetics, misinformation (e.g. 'leather' seats), and consumer fantasy. How many dudes driving huge diesel trucks do you see actually towing heavy loads or picking up shipments at a loading dock? This is just the green version of the same fantasy marketing. Incidentally, I would love a solar roof if only to power a fan to keep air circulating when I have to park in the sun, and to trickle-charge the battery when I'm away on vacation. Not everything has to be an ideal solution to powering transportation.
Animats 4y ago
Tesla should offer that. They have so much electronics powered up when the vehicle is off that it runs down the battery.[1] Having a solar panel won't save much money, but at least you can drive a bit every few days during a major power outage. Something that's becoming more of an issue as infrastructure becomes less reliable. [1] https://teslamotorsclub.com/tmc/threads/battery-drain-while-parked.209938/ https://teslamotorsclub.com/tmc/threads/battery-drain-while-...
standardUser 4y ago
This seems like way too much concern over a minor luxury feature. The only borderline alarming claim is that this sub-optimal use of solar panels will take away from the limited supply of materials, but on this scale that sounds highly unlikely, and no data is provided to cause concern, just speculation.
college_physics 4y ago
Solar panels on parking lots seems to be significantly more beneficial. A true value enhancing function for vast areas that go substantially underutilized. The installation can be optimized, will cover significantly larger area, collect irrespectively of number of cars parked and protect the cars underneath. Cant think of significant downsides besides vandalism/theft
zackmorris 4y ago
Another vote from me: this article is nonsense and I don't think that HN's readership should endorse this kind of propaganda. Evidence (no affiliation): * Solar panels are approaching 50 cents per watt: https://www.altestore.com/store/solar-panels/vikram-solar-540-watt-solar-panel-p42642/ https://www.altestore.com/store/solar-panels/vikram-solar-54... * 700 watt panels are going mainstream: https://www.bluesunpv.com/bluesun-n-type-700watt-solar-panel-bifacial-210-cell-700w-solar-pv-module_p518.html https://www.bluesunpv.com/bluesun-n-type-700watt-solar-panel... * 240 V inverters are approaching 10 cents per watt (and wouldn't be needed at all if EVs accepted direct DC input like CHAdeMO and CCS to charge while driving): https://invertersrus.com/product-category/power-inverters/240-vac-60hz/ https://invertersrus.com/product-category/power-inverters/24... The future is solar cars that charge themselves while sitting idle, that power the home through bidirectional charging off the shelf: https://driveteslacanada.ca/news/ontario-man-uses-ford-f-150-lightning-to-power-home-for-close-to-two-days/ https://driveteslacanada.ca/news/ontario-man-uses-ford-f-150... This was all set to be rolled out in the early 2000s had the Bush/Gore election been decided differently and the entire weight of the industrialized world's moneyed interests hadn't decided to crush EVs. See Who Killed the Electric Car and similar for overwhelming evidence of this. Thankfully it's no longer their choice. We can build our own solar-electric vehicles now. In fact, I bought 2 panels and was in the process of building a roof rack and 5-10 kWh buffer battery to sit in the trunk of my 2013 Nissan Leaf before the economy conveniently shrank to vacuum up any available money for such projects. Edit: this sure didn't help either: https://time.com/5113472/donald-trump-solar-panel-tariff/ https://time.com/5113472/donald-trump-solar-panel-tariff/
- kibwen 4y ago
  Right, for a light passenger vehicle (smaller than a sedan, larger than a motorcycle) you can probably get 40 miles of range per day if you live in a sunny locale. That ain't road trip mileage, and it may not be economical depending on other factors, but for lots of people that would be enough.
  - Neil44 4y ago
    Really? If it’s incredibly efficient at 4mi/kWh you’d need 10kwh per day (assuming 100% efficiency) from a panel on a car roof… that doesn’t even seem close to me.
Overtonwindow 4y ago
If it ever comes to fruition, the car Aptera is able to achieve 50 miles of range on eight hours of sunlight. We don't have a garage, so I think that would be amazing to let the car sit outside in the sun and recharge rather than plugging it in. At this point, I think anything that we can do to improve the efficiency and energy generation for electric vehicles makes sense.
grammers 4y ago
Of course, it doesn't. Putting them on balconies also doesn't make sense - at least if you look at the bigger picture. The panels should be perfectly positioned to get the most out of it. Otherwise, it's simply a waste producing them - which also costs energy, resources, etc.
- Schroedingersat 4y ago
  EPBT is 4 months in excellent conditions. A south facing facade in northern scotland is about a quarter of this and can gather about 0.4kWh/day/m^2 epbt is still well under 3 years. A 2-3 bedroom apartment has about 7-14m^2 of non-window 4kWh/day isn't going to cover everything but it's decidedly not nothing.
Kim_Bruning 4y ago
Maybe not on current crop of consumer cars, but solar powered cars are definitely a thing. https://www.tue.nl/en/news/news-overview/solar-car-tue-wins-gold-at-the-world-solar-challenge-for-the-fourth-time-in-a-row/ https://www.tue.nl/en/news/news-overview/solar-car-tue-wins-...
- rcxdude 4y ago
  These are heavily optimised race cars, not practical production vehicles. (the WSC has being going for a long time and is a great engineering challenge but you're never going to see something similar to these cars on the mass market).
grecy 4y ago
How about a trailer for the Tesla semi that is covered in panels (top and sides) and has just enough battery so that after about ~10 days sitting in the sun it's full. You plug it into the semi to charge it, and of course it charges it's internal battery while you're driving. A trucking company could just have 10 on them on rotation, so each day it's using a "full" one while the others charge Obviously we're not getting a ton of range, but free range is free range.
- dredmorbius 4y ago
  As with virtually every other suggestion for solar-on-vehicle for actual mobility (not house / auxiliary services): the idea becomes vastly more sensible and practical when you separate the mobile and cPV components. A battery trailer that can be coupled to a vehicle is a reasonable suggestion. I've made it myself. But for charging that battery ... you're far better off putting the PV in a fixed location well-suited to solar power, rather than on the mobile vehicle itself where the array is not usable whilst the vehicle is in motion, the hard-coupling means that the battery itself only affords a 10% duty cycle (as opposed to something closer to 30-50% if charged off-vehicle from mains), is subject to road wear (vibration, shock, collisions, debris), and adds significant mass to a moving vehicle (which reduces overall efficiency). Better yet: have that PV be part of the overall power grid so that when you don't need it to specifically charge vehicle batteries, it can serve other electrical needs. Yes, of course, if you're looking at a location that is off-grid and has little local electrical infrastructure it's possible that some fully-self-contained solution works. We do put PV on satellites and spacecraft, or on (usually small, low-draw) remote applications ... because it's difficult to run extension cords to Earth (or interplanetary) orbits, and running dedicated grid across 1,000s of km of wilderness for a single use is expensive. But again, we have other options here as well, including fuel-based power systems, radioisotope thermal generators (RTGs, for both terrestrial and space use), and possibly even small on-site next-gen nuclear plants (though I've ... concerns here, they are a serious proposal however). The real lesson on solar-powered vehicles (automobiles, lorries, ships, aircraft) is that the power density and available solar flux are simply very poorly matched. There are reasons why fuel-based prime movers were so widely adopted, and that in their stead, typical alternatives include electrified routes (for rail, and some barge traffic), or wind (the traditional option for moving ocean cargo). Direct-solar electrified transport will be at best limited, or limited to small, slow, and exceptionally light-weighted, mostly-autonomous vehicles rather than passenger or cargo services.
grecy 4y ago
Not true at all. These people [1] are driving the length of West Africa charging their EV exclusively from fold-out solar panels. In one post they said they gained about 250km (156mi) in a single day of charging. Here's how all their panels look laid out in the sun [2] [1] https://www.instagram.com/4x4electric/ https://www.instagram.com/4x4electric/ [2] https://www.instagram.com/p/CmoD0iJom10/?hl=en https://www.instagram.com/p/CmoD0iJom10/?hl=en
CephalopodMD 4y ago
As a person who lives in SF, doesn't have a garage, owns a model 3, and uses outdoor street parking, I have to disagree. The convenience of not having to periodically go to a charging station and pay a major premium for that electricity might be well worth it. Where I usually park, it's sunny 90% of the time, not too hot, and mostly unshaded. This sounds pretty close to optimal, so according to the article I could probably expect to be topped off most of the time with a good panel setup. I probably drive around 50 miles a week (not counting longer road trips) and lose charge while parked as well. Accordingly I charge up once every 2 weeks or so for about $15-20. That's about $400 a year. Not even accounting for the help on longer road trips, that makes things financially worth it in just 4-6 years for me. That's not even to mention how much more convenient and time saving it could be. I think the thing that would have me most concerned is the possibility of having my car broken into and losing the panels to theft... So probably a pipe dream for now.
- num3ric 4y ago
  Author: who lives in an apartment anyway?
- amarant 4y ago
  The reason solar on your car doesn't make sense is because the extra weight will end up costing you more energy than it brings. You simply don't get enough area on a car for the charge generated to be in any way significant. The extra couple of kgs won't use much extra energy to lug around either, but unless you drive very very little, it's likely to be a net loss in the end. Even ignoring any risk of theft, it's not worth it.
nelsonenzo 4y ago
Wrong conclusion. The problem here they are charging $2,000 for a $200 panel. I do not believe it adds much more to the manufacturing as the raw cost + sunk cost of automated design. Also, I live in Vegas and am usually parked in direct sun, almost all of his arguments are completely mute in most of south west US, and Australia. Yeah, totally agreed it's a stupid option in high density foggy London. Author needs to travel a bit, IMHO
grobbyy 4y ago
To me, the major upside is lower risk of fully dead in the water. Yes, I understand the top speed might be 5mph, or I might need to wait a day or two before driving, but in an emergency, that's a lot better than a dead car
fwungy 4y ago
I have portable panels with my Jackery. Two hundred watt panels would be the max a normal car could handle. Then you have to park in a place with optimal sun exposure to max out. Even at max, that's only enough power for hvac, and it won't be great in long cold Winters. Its probably more efficient to spend the panel money on a slightly larger battery.
deleted 4y ago
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ZeroGravitas 4y ago
The main problem for PV on vehicles is that electricity, anywhere that PV works, is about to become very cheap. So it's effectively outcompeted itself. The further advances of rapid and wireless charging and batteries are also undercutting the need. PV is going to end up everywhere though. It'll be cheap enough to build into all windows and building facades. So it'll be on most vehicles too.

101 points by elorant 4y ago

I agree but not completely. People seem to do the math and get maybe 5-10 miles of range per day. I’d say that actually quite useful. Especially if you only drive around town or leave your car for days at a time. Or imagine running out of battery in the middle of nowhere with no phone reception. Just wait a day and keep driving to a better spot. That’s really useful. Finally this ignores the idea of having panels that fold out when you park. You could easily 4x your solar collecting area and get some real range.

sclarisse 4y ago
Does it often happen that the typical driver of a car is somewhere in the middle of nowhere, with no cell reception? If not, it seems of limited usefulness.
- bilsbie 4y ago
  Cell phone reception is actually pretty spotty once you leave urban areas. So it could be more frequent than you’d think. And beyond that it’s harder to call for a charge up than for a can of gas. So options might also be limited.
tomrod 4y ago
5 - 10 miles per day of sunshine = 1200 to 2400 miles in high sunny place, 600 to 1200 miles in low sunny place (speculating). Not bad value add.
- AdrianB1 4y ago
  Bad value versus what? If you invest the same money in a stationary PV grid at home, it is a much better value, that is the point of the article. As I have a PV grid at home I mostly agree with that.
  - tomrod 4y ago
    Nice, I like when people add home PV. Is it always an either/or decision then?
    - AdrianB1 4y ago
      From an economic and environmental perspective home PV make sense (but the investment takes many years to recover), on cars not at this point, maybe in the future. The article describes options less than 1 KW, at home you put 5-20KW, it's a very different kind of beast.
      - steveBK123 4y ago
        Yes, and people don't understand that EVs actually use quite a lot of power relative to a freestanding home. If your home uses gas/oil for heat & hot water, you might only use, say 20kWh/day in winter and 35kWh/day in summer. This matches pretty well with the amount of solar generation you can put on your roof! The cool thing too is that you get more sun in summer, when it is hotter.. and you use more electricity because of the AC.. so it matches pretty well! Now that same 20KwH in winter is enough to fill 20-30% of your battery of your EV to drive 60-80mi. Your little car roof will generate minuscule amounts of power by comparison to your entire homes roof, while also being at the wrong angle, sometimes parked indoors or in shade, or in motion & not charging during daylight hours.
  - Forge36 4y ago
    35% of people do not own a home. This could be a reasonable middle ground. It's not as efficient as a home system, and it doesn't need to be
steveBK123 4y ago
You've just added a motor, a wear&tear item, another $1000 in cost to the panels by adding the folding mechanism. Don't forget some sensors to ensure the car can't be put into drive while panels are folded out. How much charging time gets consumed back by the panel fold in/out movement? Does the car now need an interface to allow the user to select when to fold out (long planned parking only?). This is not set-it-and-forget-it convenience.
myself248 4y ago
Yeah, 5 miles a day would cover 99% of my driving lately. When the Aptera announcement came out, I analyzed my fuel receipts, and concluded that I would plug the car in 2-3x a year (occasionally I find myself in Chicago or other day-trips), but the rest of the time solar would more than cover my usage. And that's assuming some hefty derating for latitude, cloudy weather, etc. I just don't drive that much, but when I do, it's places and times that aren't well served by transit so I very much need a car. If I go back to working at the office and solar only covers a portion of my driving, that would still likely mean plugging in once a month instead of once a week without the solar, which is still pretty cool. I think this article is "it's not a 100% solution so therefore it's a 0% solution", which is a pretty tired tactic at this point.
- steveBK123 4y ago
  The number of people who need a car and drive less than 5 miles a day is a small circle. Have you considered walking, biking, or an e-bike? It's recommended that people walk about 5mi/day anyway..
  - myself248 4y ago
    I hadn't considered walking, never heard of it actually. Thanks, let me look that up!
    - steveBK123 4y ago
      It's pretty good, but big tech/auto doesn't want you to know this one trick!
  - ramesh31 4y ago
    >Have you considered walking, biking, or an e-bike? It's recommended that people walk about 5mi/day anyway.. This comes up every time, and it's simply not an option for the vast majority of the US population.
    - steveBK123 4y ago
driverdan 4y ago
Because the math doesn't make sense. The added weight, build cost, and complexity make it less value than plugging in. Your "running out of battery in the middle of nowhere" scenario doesn't make sense. If you're that close to help you can walk there in less time than it'd take to charge the car.
pornel 4y ago
This stranded scenario is a such solution in search of a problem. The charge rate is slower than walking speed, and 5-10 miles is an easy walk (likely preferable to spending whole day roasting in a car without A/C). Besides, EVs don't suddenly run out of battery like you imagine. Batteries display state of charge very accurately, so you'd know way ahead of time if you shouldn't be heading towards middle-of-nowhere. But even then, EVs don't run out of battery suddenly, but gradually lose power and get slower. To get stranded, you'd have to be a fool ignoring all predictions, satnav, and then stubbornly drive slower and slower for 20+ miles while all the warnings are beeping at you.

t344344 4y ago

Solar panels make great sense on ICE vehicles. Trickle charge from small solar panel may preserve internal battery much better. And there are RVs. Some people use solar panels on cars as their only source of electricity!

AdrianB1 4y ago
RV and sailing boats have a relatively large area that can be used for panels. Small installations (less than a couple of kW) have a low efficiency, the inverter and storage losses benefit of scale are lost.
steveBK123 4y ago
RVs are by their nature stationary for long periods of time, and the RV are using the solar to power appliances & creature comforts inside.. which is rounding error next to moving a multi-ton vehicle.
- t344344 4y ago
  What is your point? Article says that it "makes no sense", I provided two counter examples. ICE cars also have batteries, if that gets flat, car is not going anywhere. Solar panels can be quite essential, if vehicle is parked for extended periods. It is not just some rounding error!
  - steveBK123 4y ago
    RVs also generally have spare tires, fridges, microwaves and beds! Why doesn't my sedan? Tesla needs to release a Model S with a microwave, fridge, spare tire and bed!
    - t344344 4y ago
      Again! Trickle charge from solar panel extends battery life of internal (part of ICE) lead battery. This battery slowly discharges from internal resistance, other electronics (car alarm), GPS spyware... That means less batteries, less lead in nature, more green stuff, happy Gaia... And even EVs like Tesla has slow discharge. It makes sense to put small solar panels on top, so they can do firmware updates. https://hackaday.com/2020/03/10/solar-panel-keeps-car-battery-topped-off-through-obd-ii-port/ https://hackaday.com/2020/03/10/solar-panel-keeps-car-batter...

wazoox 4y ago

This article is thin on content and wrong on many many points. 1° the Lightyear Zero is actually in production. There is no reason to think the cars built won't be sold soon... 2° the lightyear 0 has a sophisticated series of controllers for its solar cell that can activate solar cells independantly, therefore it's definitely no losing 50% of its power when 5% of the panel is in the shade. 3° dust doesn't reduce solar output that much. Washing the panels once a year is generally enough, and most people wash their cars more often than that. I love back-of-envelope calculations to check for lies, but they shouldn't preclude making your minimal homework first...

moffkalast 4y ago
> sophisticated series of controllers for its solar cell that can activate solar cells independently, therefore it's definitely no losing 50% of its power when 5% of the panel is in the shade Aka just putting a single bypass diode on every cell, it's not complicated.
bouk 4y ago
Lightyear zero is no longer in production: https://lightyear.one/articles/lightyear-decides-to-fully-focus-on-lightyear-2 https://lightyear.one/articles/lightyear-decides-to-fully-fo... And it seems like the whole company might be bankrupt.
mikestew 4y ago
the lightyear 0 has a sophisticated series of controllers… It was an extra $50 to get a controller for our RV solar that has that same functionality. MPPT solar chargers are hardly “sophisticated“ anymore. Speaking of chiding others for doing homework, the Lightyear is no longer in production: https://techcrunch.com/2023/01/23/lightyear-stops-production-on-e250000-solar-powered-ev/ https://techcrunch.com/2023/01/23/lightyear-stops-production...
jillesvangurp 4y ago
Aptera is also close to production. Several other, manufacturers are adding solar to their vehicles. Also, there are a few electrical campers with some solar panels. So, basically these things are coming to market. And why not, it makes a lot of sense. Most cars don't drive most of the time. And if they are catching any light, you basically top up the battery a little bit for free. Or put differently, that's energy you don't have to pay for. Yes, it adds some cost. And it saves you money. Kind of balances things out pretty quickly. And it adds some convenience for day to day use where you add enough power that you don't have to go to a charger so often. Especially for short commutes, this makes a lot of sense. Dust is not a big deal. Indeed nothing a good old car wash can deal with. Or a bit of rain. Panel degradation happens very slowly otherwise. I don't think that's a huge concern.

steveBK123 4y ago

Yes. This pops up on EV forums/reddit regularly "hey why don't we just put the solar panels on the car". It's a bearish indicator when any EV startup pumps a new prototype where this is a key feature. Short version: adds weight and maybe $2000 manufacturing cost to the car. Best case current tech it maybe adds $50/year of electricity to your car, requiring you to park outdoors, in good FULL sun, in parts of the world that get a lot of sun-hours-per-year. Further solar roof of a car is not at the idea angle that a home roof is. Remember while you are parking your car in said parking spots you are also baking the insides so in weather above say 55F, it will get quite hot and probably need to turn on the HVAC systems to cool the cabin and/or battery periodically.. wiping out some of your solar charging gains. Aesthetically, tt replaces the lovely glass roof many EVs have and so makes the experience worse. If you have a garage charger or charger at work, this is rounding error and irrelevant. If you don't and need to fast charge regularly, the fact that your car adds LESS THAN 1kWh/day from solar charging will save you.. 24 seconds of fast charging, per day of solar charging.. lol.

JKCalhoun 4y ago
A solar carport sounds ideal. Guessing many HOA's would lose their shit over that though.
- matthewdgreen 4y ago
  This is the one I want to build (though in a smaller size.) It’s attractive and uses panels directly as the roof. I am debating whether to get into a war with my HOA over it. https://timberhomesllc.com/our-work/outdoor-structures/vermont-solar-carport/ https://timberhomesllc.com/our-work/outdoor-structures/vermo...
  - chipsa 4y ago
    If your state has rules about HOAs not being able to block solar panels, it's probably worth it.
- Rebelgecko 4y ago
  Those are becoming somewhat common for big parking lots in Southern California, like at schools

GoToRO 4y ago

Tldr if you do everything wrong, like we say you will, then it will not work on some edge cases that we state they are very important for all people at all times.

threeseed 4y ago

> You can build a small installation for your house * 30% of Europeans rent. 50% for Germany. * 46% of Europeans live in apartments. 63% for South Korea. It reminds me of the whole "just install a charger at home" argument. It simply isn't an option for a large percentage of the world and alternatives will be needed. Solar cars may have some impractical elements but at least it's workable.

andrepd 4y ago
If they live in an apartment in a dense city then EVs aren't the solution anyways: e-bikes and public transport are, not clogging the city with electric SUVs transporting mostly one person at a time.
- threeseed 4y ago
  So all of Europe, South Korea etc are going to abandon their cars in favour of public transport and e-bikes. And this hasn't happened already because ..
  - GaggiX 4y ago
    If you live in an European city you are probably already using the public transportation, plus cities are now full of e-bikes and e-scooters, this was not true until a few years ago, so yes, it is already happening, particularly for the 46% of Europeans you mentioned earlier.
    - threeseed 4y ago
      Europe is a $413.50bn car market [1] I am going to take an educated guess that your views do not align with the majority of Europeans. [1] https://www.statista.com/outlook/mmo/passenger-cars/europe https://www.statista.com/outlook/mmo/passenger-cars/europe
      - xxs 4y ago
        In most of the EU larger cities is next to impossible to go work by car. If the office is outside the city and it has a large parking area - yes, but that's quite unlikely.

sollewitt 4y ago

There's the benefit of figuring out mass market car integration. It may be we have to rethink what a car is - competitions like the American Solar Challenge show you can run minimal cars for thousands of miles on solar: https://www.americansolarchallenge.org/ https://www.americansolarchallenge.org/ - which is great, but they will never address mass market industrial engineering.

bilsbie 4y ago

How come no one is building a portable EV Charging kit with a bunch of panels you can spread around the area. Maybe in the 1000-4000$ range. It’s strange there’s nothing in between roof top solar for your whole house and a dinky panel built into your car roof.

JKCalhoun 4y ago
I imagine those would get swiped pretty fast.
driverdan 4y ago
Because it doesn't make any sense. No one is going to put up and take down a giant solar panel array to charge their car.
- steveBK123 4y ago
  Yeah but what about a wind vane that deploys from my car roof to re-charge my battery while I am driving? /s Also what about if we also put solar panels in front of the the headlights so we can charge the car in the dark? /s
  - twobitshifter 4y ago
    Wind powered cars are possible and pretty cool. Turbines could use the apparent wind to generate just the same way it’s used by sailboats to go faster than the wind. https://m.youtube.com/watch?v=jyQwgBAaBag https://m.youtube.com/watch?v=jyQwgBAaBag
    - steveBK123 4y ago
      dude I was making jokes about perpetual motion machines
AdrianB1 4y ago
They are an electrocution hazard, the voltage on a string of panels is several hundred Volts, enough to die. One can build a fool-proof system, but the current devices and connectors are meant for static configurations handled by a qualified installer. You can DIY, but most people cannot do that safely. Also a 500W panel is ~ 20 KG (~45 pounds) and an MPPT can exceed that weight. For a car with a battery that is tens of KW, any portable system that is less than a few KW is not very useful, charging the car 5% per day is not feasible for most.

Forge36 4y ago

Not everyone parks indoors. Not everyone has reliable access to charging. This could be added to a plug in hybrid (mine only gets 20 miles electric, which covers my summer commute). Should solar panels be added to every electric car? No. Could this be an option for some people to reduce dependency on gas who are otherwise unable? Maybe.

thomaslangston 4y ago

One way to approach the engineering question of how to make solar cars for the mass market is to push the car body design to be extremely efficient. Aptera's three wheel, two seat, design seems more likely to deliver the type of daily range extension that will make solar cars a contender in the market. https://aptera.us/vehicle/ https://aptera.us/vehicle/

steveBK123 4y ago
Aptera is not long for this world, especially now that ZIRP is over. Pointing to Aptera as an example of why this is feasible is like pointing go some screen grabs of Duke Nukem Forever in 1999. Solar roof cars are like the Google Glass of EVs.
- thomaslangston 4y ago
  This doesn't compute. Higher interest rates makes a highly efficient and modestly sized two seater more attractive not less.
  - michaelt 4y ago
    Higher interest rates are good for efficient cars, true. But higher interest rates are bad for startups with no revenue, who rely on venture capital to avoid bankruptcy.
    - throwawaymaths 4y ago
      Depends. There are venture capitalists who are looking at the interest rate shift and claiming they are shifting away from low capex lottery tickets to taking another look at high capex, especially if there are fanatical buyers on the market. That said: 1. VCs say a lot of things, and don't always put their money where they say they do. 2. It's troubling that aptera is going for even more equity crowdfunding, and that they are throwing a lot of their fanatical (first mover) supporters under the bus by preference exclusively to crowdfund investors, it's a sign of desperation.

freitzkriesler 4y ago

Except a Maybach from the 2000s has a PV panel on it for powering the Aircon and built in champagne cooler https://www.autoblog.com/2007/10/19/its-friday-300-000-car-with-solar-panels-in-the-roof/ https://www.autoblog.com/2007/10/19/its-friday-300-000-car-w...? Sure, solar panels on low end EV cars are unnecessary but if I'm paying six figures for a sporty golf cart I want a solar panel to keep the inside cool. Theres a segment of the automobile buying public who will purchase a car with one integrated over others that don't.

tappaseater 4y ago

Even solar panels over a bank of Superchargers is essentially a marketing exercise. An array over a 20 acre parking lot? Now you're talking.

steveBK123 4y ago
YES. The benefit of solar canopy over L3 charging station is almost more in the protection from sun & elements than it is the actual electrical generation. A single car parking spot worth of canopy could maybe generate 20kWh per day being very very optimistic... meanwhile L3 charging users pull down 20Kwh in about 8 minutes of charging.
bertil 4y ago
I agree that it’s generally not enough, but it feels really well-aligned. It offers shelter, prevents the car from overheating, distributes resiliency where people need it, reduces the dependency on electricity transport infrastructure, answers the annoying question about the fossil-fuel-dependent grid, etc. But I agree: you don’t want just the loading section, but every parking lot to be entirely covered, resting area, play pen and access road too. Mainly because those are available areas that could use the shelter and, if anything, for more marketing: brand the panels to make the fast chargers in the corner of the parking lot that much more apparent. I actually would rather have a (slow) charger at every spot in that lot, to tell all car users: if you had an electric car, you could fill up while you shop. No need for the big fast one. More so: even then, you are still right that we need more. Have agri-voltaic near the fast chargers to show people how those work, or non-polluting industry that need large amount of electricity: Hydrogen generation maybe? It would reduce the dependency on infrastructure. It would be striking to have people take a break from the road near modern installations that demonstrate that we can have less polluting options.

googlryas 4y ago

Hell, solar panels on houses make no sense either - unless you can store/use the power locally(which many houses cannot) and don't have land to put them on the ground. Better to put all of them in a big field. Easier, safer, and cheaper to install and maintain.

TillE 4y ago
Right, solar on building roofs is fine and good, it's not nothing, but it's not a serious way to grow renewable energy. It's thinking far too small-scale. If the grid is fully modernized and using 99% renewables, there are very few reasons to want photovoltaic panels on cars. So you focus on what's cheap and scalable.
- Schroedingersat 4y ago
  Here's one of many reasons: Keep the inside cool if left in the sun without draining the battery.

powerbroker 4y ago

I note that among the costs for the inefficient car+solar combination, that the CO2 emissions just to make the panels, the inverters, the controls, and the assembly are not mentioned. The article does compare the install on a residential roof -- indicating far greater efficiencies are obtained, without the cost of using extra electrons to carry the extra weight of the aforesaid 'extras'. Aptera, has been suggesting this and going bankrupt at least once, while 'trying' to get to mass production. Their delays make Tesla look positively lightning fast (see, Cybertruck).

steveBK123 4y ago
Some of these companies going nearly bankrupt before they've even started production is telling. When you are just designing the thing, your costs are basically staff. Now trying to scale production you have all sorts of capital expenses and then operational costs that don't get recouped until you have scaled production enough. Designing a car is not a hurdle. Building a prototype is not a hurdle. Having 20k pre-sales is not a hurdle. Actual serial production in an operational factory able to ship 10k+ year is your first hurdle. Doing the above while selling the cars for enough money to not go bankrupt, while opening some sort of service network for the cars .. is a big hurdle. Getting closer to 100K/year, is the next real hurdle. And being a real big boy automaker in the 1M/year range is
DennisP 4y ago
That Aptera that went bankrupt was actually a diesel-electric hybrid, supposed to achieve 300mpg. They had to close shop when they didn't get the funding they needed. The founders went on to other things for a few years. Now they seem to be making pretty solid progress. I don't think putting "trying" in scare quotes is justified; launching a car company isn't an easy task.

DueDilligence 4y ago

.. sounds like fossil fuel propaganda to me .. yawn. next.

rsolva 4y ago

The german company Sion [0] is close to launching a reasonably priced, solar covered car. For me, their open approach is more important than the solar panels. They have a strong commitment to the community and are transparent and publish regular reports and insights to their progress. They also take a open-source aproach to maintenance, basically releasing everything you (or your local repair shop) need to fix things, and they try to choose readily available parts when possible. [0] https://sonomotors.com/ https://sonomotors.com/

florakel 4y ago
At this stage it looks very unlikely this car will ever make it to production. They ran out of money and try to save the program through crowdfunding https://electrek.co/2023/01/26/the-future-of-solar-evs-dims/ https://electrek.co/2023/01/26/the-future-of-solar-evs-dims/
rsolva 4y ago
Yeah, I know and this was what I most feared would happen as I kept an eye on this project over the years. It was always going to be a long shot, but one worth giving a go.

legulere 4y ago

The article doesn't consider that in a lot of European cities curb-side parking is very common. People have no garage and usually drive very few kilometers.

reeckoh 4y ago

Of course solar panels cannot provide enough power to drive a car for any significant distance, but that doesn't make them useless. I know, because I put solar panels on an ICE car's roof several years ago. They charged a recreation battery in the boot, which I used to charge my phone, headlamp, camp lights, laptop, radio, smaller power bricks... Fantastic for camping, and it lets you jump-start your own car. The article's prices are for first-party solutions; I paid $2/W and it's been zero maintenance over highways, bumpy tracks, heat, car washes, and frost. Using amorphous cells instead of monocrystalline can net you a bit of energy on cloud/rainy days too, even if they are less efficient in bright sunlight. If you have roof rails or a pickup canopy, give it a try. The hardest part is finding a way to get the wires into the interior. Don't forget some soft cushioning washers in the mounting nuts and bolts.

grecy 4y ago
I have two 100W panels on top of the Jeep I drove around Africa for three years. They charge a secondary battery and run the fridge, the water pump and UV Filter, camping / interior lights, all my chargers and laptop charging. [1] I also had a 100W Panel on the vehicle I just drove around Australia for 18 months. In both cases, I'd say they were essential [1] theroadchoseme.com/the-jeep

bertil 4y ago

Those articles miss that there are many vehicles, not just individual cars. Some use cases combine well with a vehicle being outside, slow, and not going far. Aptera is an excellent example of a fun vehicle that leverages its aero-dynamism. I’m not sure why the boxer van market isn’t the most obvious candidate, both for delivery companies (extending an otherwise relatively short radius and lowering the cost of battery seem well aligned) and camper-van, where the autonomy sounds worth the cost. Big rigs also feel like the perfect candidate, assuming someone can figure out how to attach panels when the load is detachable. Trains are fantastic options, although not as perfect as having panels along the rails. Airplanes, even more so — although, yes, integrating into the structure isn’t a done deal. Rickshaws are another obvious example: they can run without pedaling if the whole roof is a solar panel. There’s also a more accessible version of a bike for road trips that could leverage the bicycle-with-a-roof format well. Boats are surprisingly appropriate candidates. Leisure boats, in particular, are mainly used when it's sunny. The water offers extensive cooling available. There are electric waterboards that might not have a roof but still have enough surface to be promising—although I think a new format, akin to a wind- or kite-surf, might make more sense. Too much of the logic starts with assuming people are driving a sedan or an SUV. That’s a terrible idea. It already kills millions every year. We can’t let that lack of imagination also kill electrification.

ajross 4y ago

FWIW: on the other hand covering a EV charger spot with solar in a clear environment can almost pay for the net charging done as long as you have a battery local that can buffer.

dredmorbius 4y ago
Or just connect that PV array to the overall grid and supply / request surplus / deficit power as needed.

turtlebits 4y ago

Solar panels on cars are fine. The problem is marketing it as some revolutionary feature that differentiates from the rest of EVs, when it should just be a bullet point next to weatherproof floor mats. Perform studies, get real numbers, otherwise, you're just going to get a bunch of disappointed customers. Having to think about where to park my car to maximize my range is only going to add to EV range anxiety (not lessen it) if you don't have a reliable place to charge.

egberts1 4y ago

This solar panels on vehicles would make most sense in Sahara, Gobi, and Outback.

snozolli 4y ago

Panels are installed in locations and at angles to avoid shading as much as possible, but when you have the panel on your car, you have none of that luxury That sounds like a shortcoming of implementation, not proof that the concept is bad. Yes, I'm suggesting that cars with solar panels should have tilting, sun-tracking roofs. Not that it matters. The reason cars do or do not come from the factory with solar roofs is sales. If the market pays for it, it stays. If they don't, then it goes. I've seen countless people pay thousands of dollars for "ground effects" which are nothing but painted plastic glued and/or screwed to the car body, chrome packages, blackout packages, and 'leather' seats that are actually vinyl and less comfortable than cloth. A significant portion of the automotive market is driven by aesthetics, misinformation (e.g. 'leather' seats), and consumer fantasy. How many dudes driving huge diesel trucks do you see actually towing heavy loads or picking up shipments at a loading dock? This is just the green version of the same fantasy marketing. Incidentally, I would love a solar roof if only to power a fan to keep air circulating when I have to park in the sun, and to trickle-charge the battery when I'm away on vacation. Not everything has to be an ideal solution to powering transportation.

Animats 4y ago

Tesla should offer that. They have so much electronics powered up when the vehicle is off that it runs down the battery.[1] Having a solar panel won't save much money, but at least you can drive a bit every few days during a major power outage. Something that's becoming more of an issue as infrastructure becomes less reliable. [1] https://teslamotorsclub.com/tmc/threads/battery-drain-while-parked.209938/ https://teslamotorsclub.com/tmc/threads/battery-drain-while-...

standardUser 4y ago

This seems like way too much concern over a minor luxury feature. The only borderline alarming claim is that this sub-optimal use of solar panels will take away from the limited supply of materials, but on this scale that sounds highly unlikely, and no data is provided to cause concern, just speculation.

college_physics 4y ago

Solar panels on parking lots seems to be significantly more beneficial. A true value enhancing function for vast areas that go substantially underutilized. The installation can be optimized, will cover significantly larger area, collect irrespectively of number of cars parked and protect the cars underneath. Cant think of significant downsides besides vandalism/theft

zackmorris 4y ago

Another vote from me: this article is nonsense and I don't think that HN's readership should endorse this kind of propaganda. Evidence (no affiliation): * Solar panels are approaching 50 cents per watt: https://www.altestore.com/store/solar-panels/vikram-solar-540-watt-solar-panel-p42642/ https://www.altestore.com/store/solar-panels/vikram-solar-54... * 700 watt panels are going mainstream: https://www.bluesunpv.com/bluesun-n-type-700watt-solar-panel-bifacial-210-cell-700w-solar-pv-module_p518.html https://www.bluesunpv.com/bluesun-n-type-700watt-solar-panel... * 240 V inverters are approaching 10 cents per watt (and wouldn't be needed at all if EVs accepted direct DC input like CHAdeMO and CCS to charge while driving): https://invertersrus.com/product-category/power-inverters/240-vac-60hz/ https://invertersrus.com/product-category/power-inverters/24... The future is solar cars that charge themselves while sitting idle, that power the home through bidirectional charging off the shelf: https://driveteslacanada.ca/news/ontario-man-uses-ford-f-150-lightning-to-power-home-for-close-to-two-days/ https://driveteslacanada.ca/news/ontario-man-uses-ford-f-150... This was all set to be rolled out in the early 2000s had the Bush/Gore election been decided differently and the entire weight of the industrialized world's moneyed interests hadn't decided to crush EVs. See Who Killed the Electric Car and similar for overwhelming evidence of this. Thankfully it's no longer their choice. We can build our own solar-electric vehicles now. In fact, I bought 2 panels and was in the process of building a roof rack and 5-10 kWh buffer battery to sit in the trunk of my 2013 Nissan Leaf before the economy conveniently shrank to vacuum up any available money for such projects. Edit: this sure didn't help either: https://time.com/5113472/donald-trump-solar-panel-tariff/ https://time.com/5113472/donald-trump-solar-panel-tariff/

kibwen 4y ago
Right, for a light passenger vehicle (smaller than a sedan, larger than a motorcycle) you can probably get 40 miles of range per day if you live in a sunny locale. That ain't road trip mileage, and it may not be economical depending on other factors, but for lots of people that would be enough.
- Neil44 4y ago
  Really? If it’s incredibly efficient at 4mi/kWh you’d need 10kwh per day (assuming 100% efficiency) from a panel on a car roof… that doesn’t even seem close to me.

Overtonwindow 4y ago

If it ever comes to fruition, the car Aptera is able to achieve 50 miles of range on eight hours of sunlight. We don't have a garage, so I think that would be amazing to let the car sit outside in the sun and recharge rather than plugging it in. At this point, I think anything that we can do to improve the efficiency and energy generation for electric vehicles makes sense.

grammers 4y ago

Of course, it doesn't. Putting them on balconies also doesn't make sense - at least if you look at the bigger picture. The panels should be perfectly positioned to get the most out of it. Otherwise, it's simply a waste producing them - which also costs energy, resources, etc.

Schroedingersat 4y ago
EPBT is 4 months in excellent conditions. A south facing facade in northern scotland is about a quarter of this and can gather about 0.4kWh/day/m^2 epbt is still well under 3 years. A 2-3 bedroom apartment has about 7-14m^2 of non-window 4kWh/day isn't going to cover everything but it's decidedly not nothing.

Kim_Bruning 4y ago

Maybe not on current crop of consumer cars, but solar powered cars are definitely a thing. https://www.tue.nl/en/news/news-overview/solar-car-tue-wins-gold-at-the-world-solar-challenge-for-the-fourth-time-in-a-row/ https://www.tue.nl/en/news/news-overview/solar-car-tue-wins-...

rcxdude 4y ago
These are heavily optimised race cars, not practical production vehicles. (the WSC has being going for a long time and is a great engineering challenge but you're never going to see something similar to these cars on the mass market).

grecy 4y ago

How about a trailer for the Tesla semi that is covered in panels (top and sides) and has just enough battery so that after about ~10 days sitting in the sun it's full. You plug it into the semi to charge it, and of course it charges it's internal battery while you're driving. A trucking company could just have 10 on them on rotation, so each day it's using a "full" one while the others charge Obviously we're not getting a ton of range, but free range is free range.

dredmorbius 4y ago
As with virtually every other suggestion for solar-on-vehicle for actual mobility (not house / auxiliary services): the idea becomes vastly more sensible and practical when you separate the mobile and cPV components. A battery trailer that can be coupled to a vehicle is a reasonable suggestion. I've made it myself. But for charging that battery ... you're far better off putting the PV in a fixed location well-suited to solar power, rather than on the mobile vehicle itself where the array is not usable whilst the vehicle is in motion, the hard-coupling means that the battery itself only affords a 10% duty cycle (as opposed to something closer to 30-50% if charged off-vehicle from mains), is subject to road wear (vibration, shock, collisions, debris), and adds significant mass to a moving vehicle (which reduces overall efficiency). Better yet: have that PV be part of the overall power grid so that when you don't need it to specifically charge vehicle batteries, it can serve other electrical needs. Yes, of course, if you're looking at a location that is off-grid and has little local electrical infrastructure it's possible that some fully-self-contained solution works. We do put PV on satellites and spacecraft, or on (usually small, low-draw) remote applications ... because it's difficult to run extension cords to Earth (or interplanetary) orbits, and running dedicated grid across 1,000s of km of wilderness for a single use is expensive. But again, we have other options here as well, including fuel-based power systems, radioisotope thermal generators (RTGs, for both terrestrial and space use), and possibly even small on-site next-gen nuclear plants (though I've ... concerns here, they are a serious proposal however). The real lesson on solar-powered vehicles (automobiles, lorries, ships, aircraft) is that the power density and available solar flux are simply very poorly matched. There are reasons why fuel-based prime movers were so widely adopted, and that in their stead, typical alternatives include electrified routes (for rail, and some barge traffic), or wind (the traditional option for moving ocean cargo). Direct-solar electrified transport will be at best limited, or limited to small, slow, and exceptionally light-weighted, mostly-autonomous vehicles rather than passenger or cargo services.

grecy 4y ago

Not true at all. These people [1] are driving the length of West Africa charging their EV exclusively from fold-out solar panels. In one post they said they gained about 250km (156mi) in a single day of charging. Here's how all their panels look laid out in the sun [2] [1] https://www.instagram.com/4x4electric/ https://www.instagram.com/4x4electric/ [2] https://www.instagram.com/p/CmoD0iJom10/?hl=en https://www.instagram.com/p/CmoD0iJom10/?hl=en

CephalopodMD 4y ago

As a person who lives in SF, doesn't have a garage, owns a model 3, and uses outdoor street parking, I have to disagree. The convenience of not having to periodically go to a charging station and pay a major premium for that electricity might be well worth it. Where I usually park, it's sunny 90% of the time, not too hot, and mostly unshaded. This sounds pretty close to optimal, so according to the article I could probably expect to be topped off most of the time with a good panel setup. I probably drive around 50 miles a week (not counting longer road trips) and lose charge while parked as well. Accordingly I charge up once every 2 weeks or so for about $15-20. That's about $400 a year. Not even accounting for the help on longer road trips, that makes things financially worth it in just 4-6 years for me. That's not even to mention how much more convenient and time saving it could be. I think the thing that would have me most concerned is the possibility of having my car broken into and losing the panels to theft... So probably a pipe dream for now.

num3ric 4y ago
Author: who lives in an apartment anyway?
amarant 4y ago
The reason solar on your car doesn't make sense is because the extra weight will end up costing you more energy than it brings. You simply don't get enough area on a car for the charge generated to be in any way significant. The extra couple of kgs won't use much extra energy to lug around either, but unless you drive very very little, it's likely to be a net loss in the end. Even ignoring any risk of theft, it's not worth it.

nelsonenzo 4y ago

Wrong conclusion. The problem here they are charging $2,000 for a $200 panel. I do not believe it adds much more to the manufacturing as the raw cost + sunk cost of automated design. Also, I live in Vegas and am usually parked in direct sun, almost all of his arguments are completely mute in most of south west US, and Australia. Yeah, totally agreed it's a stupid option in high density foggy London. Author needs to travel a bit, IMHO

grobbyy 4y ago

To me, the major upside is lower risk of fully dead in the water. Yes, I understand the top speed might be 5mph, or I might need to wait a day or two before driving, but in an emergency, that's a lot better than a dead car

fwungy 4y ago

I have portable panels with my Jackery. Two hundred watt panels would be the max a normal car could handle. Then you have to park in a place with optimal sun exposure to max out. Even at max, that's only enough power for hvac, and it won't be great in long cold Winters. Its probably more efficient to spend the panel money on a slightly larger battery.

deleted 4y ago

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ZeroGravitas 4y ago

The main problem for PV on vehicles is that electricity, anywhere that PV works, is about to become very cheap. So it's effectively outcompeted itself. The further advances of rapid and wireless charging and batteries are also undercutting the need. PV is going to end up everywhere though. It'll be cheap enough to build into all windows and building facades. So it'll be on most vehicles too.