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Electric car that charges itself

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Re: Electric car that charges itself

#291

Post by jandrese »

agumonkey wrote: post #226
40four wrote: post #220

Earlier quoted context omitted.

This topic came up on the recent Joe Rogan with Elon Musk. Elon said they considered it, but in the end it is just not worth it. He said there is just not enough surface area on a car to contribute a worthwhile amount of electricity. The numbers quoted for this particular vehicle are very optimistic I think. If you’re lucky, you might get 5 miles a day out of it. What happens if it’s cloudy or rainy for a week? Or yo…

He didn't mention the semi ? The large flat area, long time under the sun, difference of market (no need to integrate it pretty, a simple flatbed on top would do)

The only reason it might kind of work on a car is because it is only driven a handful of miles per week. Long haul trucks don't even make much sense to electrify with current technology.

Delivery trucks make a little more sense, but they still have the problem of being in motion for a large chunk of the day. Basically you're just slightly increasing your watt mileage/range on sunny days.

Re: Electric car that charges itself

#292

Post by silvestrov »

IkmoIkmo wrote: post #136
marco_craveiro wrote: post #44

Earlier quoted context omitted.

I think in Europe many people (including myself) do less than 69 miles per week. We rely a lot on public transport for commuting and use cars only for a few things during the week. I suspect the target market will be very large here.

Not sure where the 69 figure comes from. Top post has more info: > As a back of the envelope calculation, if you covered the ~2.44 m2 roof of a VW ID3 with solar panels you'd probably see somewhere in the region of 244 kWh / year (based on typical UK solar panel generation per year - this would be more in a sunny place). At 4.3 miles/kWh that gives you just over 1000 miles / year of self charged driving. The 4.3 is p…

The average miles per day does not matter. It does not need to be usefull to everybody before it is useful to anybody.

What matters is the lowest 25% percentile. Getting 25% of the market is enough.

Re: Electric car that charges itself

#293

Post by labcomputer »

leoedin wrote: post #106

It's easy to dismiss this as green washing, but there is some value to it for city cars. The amount of electricity generated is never going to be enough to fully power the car, but that's not really the point. If having solar panels on your car roof means you can avoid charging much in summer, that will make owning an electric car for people who live in cities much simpler - and so support adoption. As a back of the…

> As a back of the envelope calculation, if you covered the ~2.44 m2 roof of a VW ID3 with solar panels you'd probably see somewhere in the region of 244 kWh / year (based on typical UK solar panel generation per year - this would be more in a sunny place).

Only 244 kWh/year?!? You'd get the same amount of energy by plugging in to a basic 120V North American household plug every weeknight (you don't even need to charge on weekends!).

Or 30 minutes per weeknight by plugging in to a basic UK household plug.

Or you could just leave it plugged in to a household outlet overnight once per week.

Re: Electric car that charges itself

#294

Post by srg0 »

40four wrote: post #242
coding123 wrote: post #223

Earlier quoted context omitted.

The 8 hours it's parked at work will likely charge the 20 mile round-trip. For some people it will literally never need to be charged or serviced. For other types, like me, I drive about 4 hours a week over 2 trips, but the rest of the time it would just sit at home, probably charging at least half of that drive time. So I would need to plug it in. That being said I'm planning out a 12Kw+ solar for home anyway.

I’m almost certain 20 miles range gained in 8 hours is not realistic. The website claims the average for this car is 112km (69.6 mi) per week. The claim of up to 245km per week is a bit misleading. Looking at the chart they provide, that assumes perfect conditions in the month of June only. A sunny week in December will only provide 70km. But going off the stated ‘average’ of 69.6 miles a week, roughly 10 miles for a…

> Elon Musk spoke about this on Joe Rogan recently, and said it’s just not worth it.

Tesla cars are heavier, twice as powerful and twice as expensive. Solar panels trade trade design freedom for utility. I'm not sure that big flat surfaces and an MPV silhouette would do well for a luxury vehicle.

Re: Electric car that charges itself

#295

Post by hnuser123456 »

iso1631 wrote: post #281
40four wrote: post #220

Earlier quoted context omitted.

This topic came up on the recent Joe Rogan with Elon Musk. Elon said they considered it, but in the end it is just not worth it. He said there is just not enough surface area on a car to contribute a worthwhile amount of electricity. The numbers quoted for this particular vehicle are very optimistic I think. If you’re lucky, you might get 5 miles a day out of it. What happens if it’s cloudy or rainy for a week? Or yo…

Musk is building cars for a mainly american style market - long drives and private parking. topping up 5 miles a day means that a full battery will last me and the 1.8 million UK cars that do under 2000 miles a year, months between having to plug in and recharge.

I'm in the US but have a 2 mile commute each way, and I don't drive to work every day (pre-covid). Uncommon but I'm not alone.

- For me, 5 miles a day would keep the battery topped off and I wouldn't have to visit a charger except on longer trips.

- Would also be much more palatable to limit the full-charge voltage to something a little lower, prolonging the battery's useful life, knowing it'll passively recharge daily.

- Would also enable more connected vehicle features.

- Given a choice between a car that slowly loses a bit of charge daily, or one that gains charge, everyone would pick one that gains.

- Would also lessen the fear of running out of charge a mile away from a charger and needing a tow truck, just wait a few hours if it's sunny, or at least charge enough to park somewhere safe and phone a friend to pick you up and leave it for a day.

- Could go on camping trips a bit further away and let it charge for a week, or use the AC/heater occasionally.

- If the car is covered in snow it can warm up the panels and melt some snow. Teslas can already do this but it's even more practical with PV on the roof.

As long as people understand this doesn't mean they can drive nonstop in the sun or that they'll get any significant short-term range boost, it's still extremely sensible.

Re: Electric car that charges itself

#296

Post by ben_w »

eldaisfish wrote: post #239
ben_w wrote: post #236

Earlier quoted context omitted.

See page 12 of your link. Most of the cost in grid connected PV isn’t the cells; stuff like installation (e.g. safety while working at heights) is famously expensive. See pages 18-19 for their estimates.

that's precisely my point. Even if most of the $2/W cost of commercial PV isn't the cell cost, the cells still cost around US$ 0.4 - 0.6 each and this is for mass produced cells. Is it fair to claim that a speciality cell such as those on this car can be had for even cheaper? Unlikely.

I’m not sure what you’re arguing against given I claimed $.30/W and the document you linked me to also claims $.30/W cells.

Re: Electric car that charges itself

#297

Post by gnramires »

samcheng wrote: post #170
gnramires wrote: post #159

Earlier quoted context omitted.

Indeed, I were once skeptical (remembering EEVBlog's Solar Roadways series) but it really seems a good deal. Short commutes in cities can probably be covered. And a killer feature to me: if you ever get stranded somewhere without power, you at least have the option to wait a day or two to charge and get to somewhere nearby with power (around 3 miles/day for ioniq, 10 miles/day average for sion according to the articl…

I'm an electric car driver, and I'm still skeptical. It's hard to imagine a scenario where I accidentally run out of batteries and then can afford to wait for MULTIPLE DAYS before finishing my trip. Pretty sure I'd at least want to get a tow to the nearest gas station, where they would be able to plug me in if necessary. Even a plain old 120V 15A plug has much more power than solar, and works overnight...

Well yes it varies a lot by condition, it seems in the worst case (temperate winter, cloudy) you get about 5 miles per day, i.e. about 1 mile per hour of daylight.

Still, it does seem like a useful feature. It should be plausible to run out of juice relatively close to an outlet (gas station, hotel, good samaritan, etc.) since electricity is virtually everywhere. Waiting a few hours to get to the nearest facility should not be too bad.

It's more of the capability that attracts me (like having insurance without ever needing).

Given typical numbers of panel output I wouldn't be surprised if it (nearly) pays for itself anyway, so I don't see the need to be overly skeptical. (ben_w estimates ~1.8 year payback)

See other arguments cited elsewhere as well: avoiding deep discharge in case of battery depletion. If you leave your depleted car sitting for a while (days? weeks?), you will see degradation of the precious battery, which represents most (about 40%) of the cost of the car. A cheap insurance to preserve your most vital asset is also a great feature.

Re: Electric car that charges itself

#298

Post by orthecreedence »

dheera wrote: post #277
orthecreedence wrote: post #272

Earlier quoted context omitted.

> Guessing HOA's would lose their shit though. Perhaps there should be legal escape hatches from HOA rules specifically for energy efficiency upgrades. I don't generally advocate for centralization of power (ie, a state imposing its will on a community), but in the case of climate change I'll happily make exceptions.

Honestly I don't see why we can't just outlaw HOAs. If you own something you should be able to do whatever you want with it. It seems like a simple constitutional right to me.

I personally hate the idea of HOAs, so I agree with you on a gut level.

Taking a wider view, HOAs are a form of free association and I can't condemn them entirely. If people want to subject themselves to complete hell, they should be able to. And frankly, the kind of neighborhood that has an HOA is not the place I'd want to live anyway, so it's not like I'm personally missing anything.

That said, the existence of HOAs should not be a driver for climate change, and aesthetics and property values are a really stupid thing to optimize for when we're facing catastrophic climate collapse.

Re: Electric car that charges itself

#299

Post by srg0 »

eldaisfish wrote: post #196
Tade0 wrote: post #174

Earlier quoted context omitted.

I see one use case: leaving the car for extended periods of time unplugged, say at an airport parking lot. Last year I had to leave my car unused for three months, after which both the 12V battery and the hybrid battery were completely discharged. Had there been a solar panel on the roof this wouldn't be an issue. Nowadays most of the cost of solar is installation, so I don't think such a panel would be very expensiv…

> I see one use case: leaving the car for extended periods of time unplugged, say at an airport parking lot. You're making a big assumption there - that the parking lot is open to the sky which many airport parking lots are not.

> You're making a big assumption there - that the parking lot is open to the sky which many airport parking lots are not.

Usually there are many parking lots open to the sky, and they even cost less.

Re: Electric car that charges itself

#300

Post by Gravityloss »

40four wrote: post #220
leoedin wrote: post #106

It's easy to dismiss this as green washing, but there is some value to it for city cars. The amount of electricity generated is never going to be enough to fully power the car, but that's not really the point. If having solar panels on your car roof means you can avoid charging much in summer, that will make owning an electric car for people who live in cities much simpler - and so support adoption. As a back of the…

This topic came up on the recent Joe Rogan with Elon Musk. Elon said they considered it, but in the end it is just not worth it. He said there is just not enough surface area on a car to contribute a worthwhile amount of electricity. The numbers quoted for this particular vehicle are very optimistic I think. If you’re lucky, you might get 5 miles a day out of it. What happens if it’s cloudy or rainy for a week? Or yo…

All Tesla models use still a lot of energy per kilometer so a solar panel is almost useless. A bicycle uses 3 kWh/100 km, while a Tesla uses maybe 20.

If you want more kilometers per day from the solar panel, it makes sense to optimize the car. More streamlining, lightweight composites, narrower tyres, wheel fairings, smaller battery etc. For example https://en.wikipedia.org/wiki/Lightyear_One

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