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Solar Powered Tesla Model 3?!

Solar Powered Tesla Model 3?!

Inspired by the Rich Rebuilds YouTube channel, I decided to conduct a redneck science experiment with my Tesla Model 3 and some solar panels. Here is my misadventure: https://youtu.be/g10Wq5Xd1L0

rdavis | 30 juin 2019

Cost vs reward.

They were trying to make an affordable car. How much does solar glass add to cost...

dgstan | 30 juin 2019

My Model 3 is already 100% solar powered. I charge at work where all of the power comes from solar panels. If I have to charge at home, it's 100% solar as well.

majassow | 30 juin 2019

Ummm, great. Now instead of parking in the shade, now you need to park in the sun. Then the car will expend MORE than 1 kwh of energy to keep the battery cool. I wouldn't pay extra for negative miles. There just isn't enough surface area for effective solar charging on a car.

leo33 | 30 juin 2019

Key words are "I imagine". It's a good bet that the fish knows very little about this topic, and again is simply reaching for a reason to be critical of Tesla's decisions. It get's old.

gballant4570 | 30 juin 2019

My Model 3 is 100% wind powered. Plenty of solar powered Model 3's already running the roads, as well as wind powered.....

jjgunn | 30 juin 2019

Once the solar cells reach at least 75% efficiency, then we'll have something.

Until then......the cost vs. the reward isn't worth the time & trouble.

kevin_rf | 1 juillet 2019

If you're in SoCal, or any place that doesn't get much snow it's cheaper and more efficient to just cover the parking area with solar panels. The shade they provide also has an added benefit.

Wait, they are already doing that all over SoCal. They stole my idea, I want my two dollars!

rob | 1 juillet 2019

It needs an outrigger for strong crosswinds. If you had full FSD you could even hike out. A jibe would be tough though.

dwakelee | 1 juillet 2019

Covering the Model 3 glass roof area with currently available solar tech would get you on the order of 50-200W depending on manufacturing and aesthetics of the integrated panels. This level of power is not something to realistically recharge the battery for driving except by a minuscule amount. However, it would be the perfect amount to run cabin overheat mode or sentry mode without depleting any range from the main battery. That is a real use-case where there is benefit.

And yes, this is being done currently by others, and has been done before...
https://understandsolar.com/prius-solar-roof/

I for one would pay for this. Greatly preferred over the present transparent glass 'premium' roof, which though UV shielded does increase cabin temperature. With Tesla having having solar tech, it is a bit of a mystery why this isn't offered. Perhaps the safety issue mentioned in the article, but having a regular glass roof has to have its own set of problems which Tesla has obviously mastered. I can't think of anyone who could do this better - odd they aren't the leader - yet.

dwakelee | 1 juillet 2019

"Covering the Model 3 glass roof area with currently available solar tech "

Yes, didn't mean to imply that you stick PV solar cells to the current glass roof. Meant 'covering' to mean the square area being available for calculation purposes.

1kW (power) not realistic with present technology and the area available. 1kWh (energy) generated over a work day would be possible.

Neomaxizoomdweebie | 1 juillet 2019

So for 1 Kw of power (equivalent to 13 cents per day) I can pay... how much more for this special roof?

FISHEV | 1 juillet 2019

" 1kWh (energy) generated over a work day would be possible."

Yes...that's what I meant.

dwakelee | 1 juillet 2019

Present PV solar costs on the order of $0.50 to $1.00 per watt. Let say we are talking a 125W setup here, and lets also say $5 per watt in this case because this is not a typical flat PV panel. So call it $625 for talking purposes. That's being conservative on both the power output, and allowing ample cost before optimizing the process.

Yes this will not be net zero cost over the life of the car, but that isn't the point. The benefit here is zero range loss when in parked outside and using these new fancy features like sentry mode, cabin overheat protection, and fast enhanced summon. Additional benefit of not needing to run as much AC when you get into the car given a solid roof covering vs. the glass roof we have today.

Maybe not a Model 3 class feature, but should at least be on the flagship S and X models in my opinion.

SteveWin1 | 1 juillet 2019

I'd think the main benefit of this would be long term parking. Right now, none of us can go on a 2-month trip somewhere and leave our cars at the airport. The car would be dead when you got back. With a solar roof, you could park in one of the off-site non-garage parking spots at an airport and it would at least keep your battery from being dead when you got back. The slow loss of energy while parked and the need to always have the car plugged in is one of the annoyances of owning an EV. With a solar roof, you would only need to ensure that you're parked in non-covered parking which would be a lot easier to do than finding somewhere to park that will allow you to plug in for extended periods of time. Something they could sell on their online shop, is a fold up solar panel set that attaches to their roof rack. If it could fold up and fit in the trunk, you could just take it out when you're going to be parked for long periods of time, attach it to the roof rack and plug it in to the regular charge port. It would provide shade and would keep your car charged up for as long as you need.

CharleyBC | 1 juillet 2019

Our 3 is also solar powered today, except when we charge on the road. And even some of those are solar (Shenandoah Vineyards destination charger, eg).

CharleyBC | 1 juillet 2019

@SteveWin1: “Something they could sell on their online shop, is a fold up solar panel set that attaches to their roof rack. If it could fold up and fit in the trunk, you could just take it out when you're going to be parked for long periods of time, attach it to the roof rack and plug it in to the regular charge port.”

That reminds me of how Mark Watney took his rover on long trips in The Martian. Long drive, then set out the panels to charge the rover while resting, then drive some more. (PS: We named our car Wattney in his honor, adding the extra T for electrical fun.)

lbowroom | 1 juillet 2019

Add a pinwheel under the front spoiler to so the car can charge itself from the wind power too.... LOL!

Magic 8 Ball | 1 juillet 2019

Just use Amazon drones to come deliver a boost when you need it, not hard.

SteveWin1 | 1 juillet 2019

@CharleyBC, haha. You're right. Good movie and great name for the car!

lbowroom | 1 juillet 2019

Should also not discount the idea of using your phone battery as a backup... pretty simple

Magic 8 Ball | 1 juillet 2019

Those supercharge stations were a silly idea, solar panels on the roof of the car definitely pencils out as being better.

Anyone know why Nissan dropped their little trickle charge panel after so many years?

tomasrey88 | 1 juillet 2019

I have no illusions of the solar roof on a Model 3 powering it for long drives. However, I would be satisfied if it just negates vampire drain and recharges the car a little. That way, if you're parked at the airport for a long time, you wouldn't come back to a dead battery. Or if you're parked in an off grid location camping for 3 months and your car charged 0.5 miles per day, at the end of your 90 day camping trip, you should have 45 miles of charge. This may be just enough to get you to the nearest electrical outlet.

My redneck science experiment and attempt at making a solar powered Tesla Model 3: https://youtu.be/g10Wq5Xd1L0

TeslaTap.com | 1 juillet 2019

Solar car roofs come up every few months here. Makes zero sense. I did the analysis with a larger Model S roof and the payback is about 110 years! Far better to put solar panels on your house. https://teslatap.com/articles/solar-vehicle-roof-analysis/

The 110 year payback also assumes no panel degradation and the car is in the sun for the entire day every day for all 110 years. For those that really want a solar car roof, technically it can be done - just not profitably.

dwakelee | 1 juillet 2019

Of course, makes zero sense for the recharge use-case. But maintaining range by avoiding vampire drain over extended periods makes total sense. In addition to combating normal discharge, can also power features like cabin overheat protection, sentry, and enhanced summon 'standby' quick wake-up (being tested now).

The scenario of people loosing get-home-range by parking at airports for extended duration also frequently comes up here. Model 3 currently has a handle on phantom drain itself - has varied over time based on firmware. But solar would be a nice solution for those who want cabin overheat protection on and sentry mode active - without loosing range to get home.

SteveWin1 | 1 juillet 2019

@TeslaTap, "makes zero sense."

what dwakelle said...

It does make sense, but depends on your goals. If you want to make your money back, then its not going to work. I bought weatherproof mats, center console wrap, extra charge adapters, etc. None of those things are going to pay me back for buying them. I bought them or the convenience or looks. This is the same thing. If I can go to the airport and leave my car in a sunny parking spot and not have to worry about how long I'm gone and what my SOC is when I get to the airport and whether or not I can afford to leave sentry mode on, then I'm happy to pay for that extra convenience. Maybe when every parking spot has a plug nearby then this won't matter.

rdavis | 1 juillet 2019

@SteveWin... I believe the calculated values of the solar panels would be less than 1 mile per full day of sunlight... I don't think that would be able to negate vampire drain...

tigerkc | 1 juillet 2019

My solar panels are 6.27 kW, and on a full sunny summer day, it can generate ~5.4 kWh each day.

On the roof of a model 3, you can probably fit 250 - 300 watts worth of solar cells which is about 215 - 258 watt-hour worth of electric power. This is not enough to overcome the vampire loss, and people think it can run the Sentry Mode, overheat protection or recharge the battery? Besides, I would rather park in a covered parking so the cabin is nice and cool and better for the paint.

FISHEV | 1 juillet 2019

" I did the analysis with a larger Model S roof and the payback is about 110 years!"

About the same for buying the Tesla. I really didn't do EV and solar for the "payback" but to cut emissions. As for your analysis, your costs make no sense. Solar PV roof would cost about the same as current glass roof. Rigging to fan etc, it was a $500 option on Prius.

"Onyx Solar Photovoltaic Glass has an average IRR of more than 70% and a payback period of less than 1 year."

https://www.onyxsolar.com/economic-feasibility/

gballant4570 | 1 juillet 2019

Most airport long term parking I've used has been under cover.....The best solar option for any car is stationary solar generation that you plug the car into to recharge the battery. Preferably, that stationary solar generation facility also has storage batteries to charge the car at night. Plug it in until you need to drive it. No vampire drain, solar heating in the wrong season, cabin overheat operational, etc....

FISHEV | 1 juillet 2019

"My solar panels are 6.27 kW, and on a full sunny summer day, it can generate ~5.4 kWh each day."

My solar panels are 8.42 kWh and on a full sunny day, it generated 8.42 kWh at peak. Daily is more in the range of 50 kWh on a sunny day, like June 3rd. You must have an odd angle if you can only get 86% peak out of the system.

Tesla parked in the sun would provide about 1kWh per day. It is shaped quite well for solar PV. The ambient cooling would likely cut parasitic losses another 1kWh a day. Per 100,000 Teslas that's 24 mW a year.

Musk should be putting solar PV glass on all Tesla's.

lbowroom | 1 juillet 2019

Solar inverters aren't 100% efficient. The best are around 95%. Don't know what kind of magic you have going on.

Your conclusions aren't valid. Ask your "consultants"

SteveWin1 | 1 juillet 2019

Please correct my math here...

Using a support that unfolds and attaches to the roof rack, you could fit the equivalent of 5 standard 65" x 38" solar panels over the car (trunk and hood included). Using weather underground's calculator, in my location these 5 panels, if you get 18% efficient panels, would generate 7.8 to 8.3 kWh per day (depending on season), on average. I think that would be more than enough, to park indefinitely, right?

lbowroom | 1 juillet 2019

Why not just tether it to the array on your rooftop?

tigerkc | 1 juillet 2019

Sorry my bad, my solar daily production is actually ~40 kWh, so it is about 7.4x of my previous calculation which amounts to 1.6-1.9 kWh. This is still a very small amount. I am assuming solar cells on the roof glass area only instead of external mounted roof panels.

For reference, my micro-invertors are max 97% efficiency, panels are 330-watt, at Azimuth 181 degree and 26.57% tilt angle (6-12 pitch). Minimal / no shading throughout the day.

FISHEV | 1 juillet 2019

"Sorry my bad, my solar daily production is actually ~40 kWh"

That sounds better. I have the SolarEdge system.

1.6-1.9 kWh a day is a lot for the solar roof on the Tesla. Going conservative with 1 kWh a day still ends up being a LOT of power in the aggregate. Tesla could take out a coal power plant with PV glass roofs on the cars and that is the mission.

rdavis | 2 juillet 2019

There is a carbon footprint for the production of that PV glass. It’s not as simple as saying you could take out a coal plant by using PV glass.

There are also other considerations like at end of life requirements for the PV glass recycling issues. Not to mention supply/production issues.

The value isn’t there yet for PV glass on top of car.

rdavis | 2 juillet 2019

@stevewin1... that sound hideous...

I was going by the video linked in OP. He determined 1 mike per day or less.

rdavis | 2 juillet 2019

@stevewin... not to mention you have to be flying carryon only... doubt you’d be able to fit/store those panels in the car when you drive to the airport.

FISHEV | 2 juillet 2019

"There is a carbon footprint for the production of that PV glass."

The same carbon footprint as non-PV glass.

Ironically, the same false argument is used against EV's overall that production negates it's no emissions operation. It's been proven false.

rdavis | 2 juillet 2019

Fish... no, solar cells themselves have a footprint. You have to produce and extract that

rdavis | 2 juillet 2019

Fish... no, solar cells themselves have a footprint. You have to produce and extract that polycrystalline silicon and metallurgical silicon.

SteveWin1 | 2 juillet 2019

@rdavis "that sound hideous..." "not to mention you have to be flying carryon only... doubt you’d be able to fit/store those panels in the car when you drive to the airport."

Haha. Yeah, it might not win any car beauty pageants, but it sounds like it would keep you from having to worry about coming back to a dead car. I'll take an ugly car that can drive away over a pretty paperweight, but aesthetics could be pretty decent, I think. Just depends on how its designed. If you've already got the Tesla roof rack, you can put luggage up there or could fold and store the solar panels up there for the drive. So, you'd be able to fly however you would normally fly. Sounds like its not something you would buy, personally. Doesn't mean there aren't people who would find value in something like this.

lbowroom | 2 juillet 2019

So the target market for this folding solar array is people who want to leave their cars at the airport for a few months?

Considering parking fees, even long term) and the cost of this system, how many times could one use Uber or even a limo service round trip from the airport?

SteveWin1 | 2 juillet 2019

@lbowroom, yes that was one example of a target market. Very good reading skills...

I thought you guys were all arguing that it couldn't be done because solar isn't efficient enough or there's not enough area or whatever. Now you're all pivoting to "it would be too ugly," "you wouldn't be able to fit any luggage in there with the solar panels," "it would cost too much," "the target market is too small." I'll take your pivoting to mean that you're conceding that it would work and it would add convenience to owning an EV. Currently the inability to park your car somewhere for a long period of time is a weakness of EVs when compared to ICE vehicles. This would eliminate or at least greatly reduce that weakness. Is it a perfect solution? No. But, I'm sure there are people who would want it. This question comes up all the time on the forum, so there are clearly people who would use it at airports, train stations, for off-grid long-term camping or staying at their log cabin up in the mountains, etc. I bet there are even some green fanatics who would buy this and use it every day at work just to prevent a couple more molecules of CO2 from ending up in the atmosphere. No clue how much this would cost. It was just an idea. The costs could be potentially mitigated by having a third party company (or Tesla directly) rent these out as needed to people who are going to need to park without electricity for long periods of time. There may not be enough EVs out there to support this business model yet, but eventually there likely will be.

Anyway, the point is, it would probably work. Quit changing the argument. ;)

SteveWin1 | 2 juillet 2019

Just having this available, even if nobody bought a single one would shut people up about the inability to park an EV somewhere for long periods. That was the motivation for having something like it -- not for it to sell like hotcakes. Anything that removes an argument against EVs is a good thing, right?

lbowroom | 2 juillet 2019

Pivoting? Not at all. I admit I lacked the imagination. Your unfolding of solar panels that are stored on a roof rack ala Mark Watney style didn't enter into my though process. The panels and the supporting inverters etc would be a significant design challenge. I'm too lazy to strap a club between the brake pedal and steering wheel. But hey, prove me wrong. You're free to design, build, and market your idea. Then you can laugh in my face and I'll graciously bow.

rdavis | 2 juillet 2019

@SteveWin1 "I thought you guys were all arguing that it couldn't be done because solar isn't efficient enough or there's not enough area or whatever. "
_______________________________

My comments are based of the OP link to video test of putting solar panels up. He concluded 1 mile or less per day.

rdavis | 2 juillet 2019

BTW, I wouldn't park my ICE or EV for a month at the airport. I'd have to take out a lone to do so....

Neomaxizoomdweebie | 2 juillet 2019

@rdavis,
Precisely. This is a job for Uber.

lbowroom | 2 juillet 2019

You'll see, he'll prove us all wrong. It can be done and people will love it!

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