Solar power roof

[MOE J]

Teslas have black glass roofs, why can’t they implement solar panels to charge the battery while the car sits in the sun all day ?. Even 5 % would be possible ?. Seems like a no brainer.

 

[cmaster]

Don't forget. Fiskar Karma already had the solar roof. Didn't work out great.

 

[MLXXXp]

Looks like its in the works. Hyundai and Toyota seem to already offer this as well.

Aptera thinks that supplemental built-in solar charging will be useful for their vehicles. I have my doubts as to how beneficial it will turn out to be in real life.

 

[MOE J]

A sun shade is not going to do anything at all to keep a car cool enough to drive in, especially if there is sun out to put power into these theoretical panels.

It was 78 degrees today and partially overcast, and I parked outside for 2 hours while I was at a doctors appointment. My car was 128 degrees inside it when I came back out to get in it.

Ya that Tesla temp is a bit off, it always says some ultra high temp but when u get inside the car it’s a lot lower. That temp gauge must measure the top of the roof.

 

[jjrandorin]

The idea of integrating solar panels into Tesla’s glass roofs to charge the battery while the car is parked in the sun is indeed intriguing! However, there are practical challenges to consider:

1. Efficiency:
   • Solar panels on a car roof would be limited in surface area compared to stationary solar panels. Achieving meaningful charging efficiency would be challenging.
   • Even with optimal positioning, the energy generated might not be sufficient to significantly impact the car’s overall range.
2. Weight and Aesthetics:
   • Adding solar panels would increase the weight of the car, affecting performance and handling.
   • Maintaining a sleek design and aerodynamics while accommodating solar panels could be complex.
3. Energy Demand vs. Generation:
   • Electric cars have substantial energy demands for acceleration, heating/cooling, and other systems. Solar panels alone might not meet these needs.
   • The energy generated during parking might not cover daily driving requirements.
4. Cost-Benefit Analysis:
   • Balancing the cost of integrating solar panels with the benefits (even a small percentage of charge) would be crucial.
   • Tesla prioritizes features that significantly impact range, safety, and performance.

A 7 kW solar array typically requires approximately 380 to 450 square feet (35-42 square meters) of space. Keep in mind that the exact space needed depends on the efficiency of the solar panels used in the installation1. To achieve a 7 kW system, you’ll need around 23 solar panels, assuming each panel is rated at 300 watts2. So, if you’re considering installing one, make sure you have enough roof or ground space available!

This reads like it was written by some large language module (chatgtp, etc). Those things love to write bulleted lists like this, with lots of fluffy words that have no real substance to them. Also, no one in this thread was talking about a 7kW solar installation, which (as the post points out) would not be appropriate to even discuss for a car roof.

 

[cmaster]

This reads like it was written by some large language module (chatgtp, etc). Those things love to write bulleted lists like this, with lots of fluffy words that have no real substance to them. Also, no one in this thread was talking about a 7kW solar installation, which (as the post points out) would not be appropriate to even discuss for a car roof.

How much power from solar panels to produce something equivalent of 32amps at 240 volt? A 7 kw solar panels array of course. Otherwise, you’re looking at a small surface area available on a small car.

 

[jjrandorin]

How much power from solar panels to produce something equivalent of 32amps at 240 volt? A 7 kw solar panels array of course. Otherwise, you’re looking at a small surface area available on a small car.

that has zero to do with this thread, however, since the thread topic was a solar roof for a Tesla. How much solar is needed for 32amps at 240v is irrelevant to that subject.

 

[cmaster]

that has zero to do with this thread, however, since the thread topic was a solar roof for a Tesla. How much solar is needed for 32amps at 240v is irrelevant to that subject.

What is the intent of having solar panels on a tesla car? How much you think it can generate with a small surface area. I think it just pollutes the mind of folks that it can do wonders.

 

[jjrandorin]

What is the intent of having solar panels on a tesla car? How much you think it can generate with a small surface area. I think it just pollutes the mind of folks that it can do wonders.

I dont think it works AT ALL, and it was pointed out by several others in this thread, but that still has zero to do with the post you posted about a 7kW solar installation that looks like it was generated by chatgtp.

 

[yesimon]

Prius Prime, Fisker Ocean, and potentially Aptera cars can have solar roofs. It generates a few miles per day in ideal conditions so it's not going to replace needing to plug in except for very rare usecases.

I could see it being somewhat useful for SoCal apartment dwellers without access to home charging. Stretching out the frequency between needing to visit public charging stations would be more useful than the actual $ value of the energy itself.

 

[DuncanM]

Lightyear designed an EV that was specified to generate up to about 7.4kw/day via it's solar panels:

https://insideevs.com/news/626100/lightyear-0-solar-ev-enters-production-at-rate-one-per-week/

Obviously, if my M3's HV battery could receive 7kwh of power into the battery/day that would give it about 50km/30miles of added range per day, which BTW, is about the average commute in North America. I think the idea of using solar to augment the car's charging is sound, but still a challenging engineering exercise.

 

[ucmndd]

Replacing a NON-solar Tesla glass roof is already a $1500 expense. I shudder at the thought of having to replace a PV roof. Having to do so even once in the lifetime of the car would completely erase any financial benefit many times over.

Count me out.

 

[DuncanM]

Replacing a NON-solar Tesla glass roof is already a $1500 expense. I shudder at the thought of having to replace a PV roof. Having to do so even once in the lifetime of the car would completely erase any financial benefit many times over.

Count me out.

PV solar panels are really cheap these days. I think your fears are unfounded.

 

[RayK]

PV solar panels are really cheap these days. I think your fears are unfounded.

But the real cheap ones are not all that efficient; somewhere around 16-19%, while the best (i.e. expensive) panels are maybe mid-20's.

 

[ucmndd]

PV solar panels are really cheap these days. I think your fears are unfounded.

Mass-produced standard form-factor roof or ground mount PV panels are "really cheap." Yes.

That has next to nothing to do with the cost of PV panels integrated into a custom, relatively low-volume piece of automotive glass.

There's no way a solar roof replacement for a Tesla costs less than ~$3,000. Minimum.

 

[DuncanM]

Mass-produced standard form-factor roof or ground mount PV panels are "really cheap." Yes.

That has next to nothing to do with the cost of PV panels integrated into a custom, relatively low-volume piece of automotive glass.

There's no way a solar roof replacement for a Tesla costs less than ~$3,000. Minimum.

Millions of standard form Tesla glass roofs are still considered 'low volume'!? Why would ~$50 worth of PV elements double the price, if all glass roof panels were so equipped right from the factory?

We have to consider mass production EV centric PV/glass roof panels. It's not a insolvable problem from an engineering or cost perspective.

 

[DuncanM]

But the real cheap ones are not all that efficient; somewhere around 16-19%, while the best (i.e. expensive) panels are maybe mid-20's.

If we had 100 million EV/PHEVs on the road in North America, even ~20% efficient PV, roof and hood, panels would contribute an enormous amount of power to the pool of generated electrical power. Go back at look at the data from the Lightyear car, in post #30 above.

 

[ucmndd]

Millions of standard form Tesla glass roofs are still considered 'low volume'!?

In the context of mass-produced standardized PV panels, yes.

Why would ~$50 worth of PV elements double the price, if all glass roof panels were so equipped right from the factory?

Because it’s not $50 to add PV elements into a custom sheet of glass in a structurally sound and relatively resilient way.

We have to consider mass production EV centric PV/glass roof panels. It's not an insolvable problem from an engineering or cost perspective.

Insolvable? No. Juice not worth the squeeze? Yes. It’s a whole bunch of complexity for a teeny tiny amount of power. The added repair and insurance costs are just not economical in my opinion. As I said, count me out. Your calculus may differ. It’s a complexity and added cost that I don’t want for what amounts to a gimmick.

 

[MLXXXp]

even ~20% efficient PV,

20% is under ideal conditions; Sun straight overhead on a cloudless day and all the solar cells directly aligned towards the Sun. That's not going to be the case most of the time. It would be better to spend the money on dedicated ground based mass or local solar power generation and use that energy to charge the cars via the grid.

 

[ucmndd]

Prius Solar Panel Failure

· I bought a 2010 Prius 3 in 2010 and now have abut 63000 miles on it. I love this car. I have had no mechanical problems except one that made itself...

priuschat.com

$2,000 replacement cost for a damaged/defective 50 watt solar roof in a 2010 Prius.

Yes, PV is cheaper now. But if you think a solar roof replacement on a Tesla would be LESS than that in 2024 dollars, I have some beachfront property in Arizona I’d like to show you.

180 watt Solar roof on a 2024 Prius Prime is a $610 up charge from the factory over the standard glass roof. Replacement cost at a dealer will easily be well north of $2k.

Again - a single replacement expense will negate ALL financial/energy benefit realized over the entire life of the car.

 

[DuncanM]

Prius Solar Panel Failure

· I bought a 2010 Prius 3 in 2010 and now have abut 63000 miles on it. I love this car. I have had no mechanical problems except one that made itself...

priuschat.com

$2,000 replacement cost for a damaged/defective 50 watt solar roof in a 2010 Prius.

Yes, PV is cheaper now. But if you think a solar roof replacement on a Tesla would be LESS than that in 2024 dollars, I have some beachfront property in Arizona I’d like to show you.

180 watt Solar roof on a 2024 Prius Prime is a $610 up charge from the factory over the standard glass roof. Replacement cost at a dealer will easily be well north of $2k.

Again - a single replacement expense will negate ALL financial/energy benefit realized over the entire life of the car.

OK, but solar roofs on Prius/P. Primes are low volume items (Hundreds or a few thousand at most). If every EV/PHEV had them as standard the unit cost would would be much lower.