2010 Solar Roof Temperature Report

I picked up a black 2010 model III with a solar roof last night and today I did a quick temperature test to see how well the solar panel driven ventilation cools the car interior. I'll continue these tests under varying conditions over the next week or so to get a good feel for how the ventilation system works in the real world.

I live in California's central valley so there are basically no clouds here and it is usually 95+ at midday. Today I parked the car in full direct sun in a gravel parking lot. After the car sat in the sun for 4 hours I tested the temperature:

Outside temp: 95
Inside car: 125

I do not yet have a heatshield for the windshield, it's on order. So the sun is baking down on the car, and dashboard. Temp should be lower once the heatshield arrives.

In future tests I will compare internal car temp with and without ventilation system on, with and without heatshield, and in different parking lots (black macadam for example).

Hope this is helpful.

Steve

That was taken with the ventilation system on?

If that was taken with the ventilation system on I'm glad I didn't cough up the extra bucks for the sunroof.

Yeah. You have to turn the system on, right?

Yes, ventilation on. Previous research says that on a day like today (95+ full sun) the temp inside a car reaches 150. So the ventilation presumably knocked the temp down 20+ degrees. I'll test without ventilation tomorrow and report back. Also: I expect that blocking the sun coming through the windshield with the heatshield should help quite a bit because as you'd expect the dashboard was very hot to the touch from the direct sun and that radiates a lot of heat.

125 F = 51C is not bad at all.
Cars can reach inside temperatures of 85C =170-180F when directly under the sun, as far as I know.
I am really interested in seeing the test results without the sun-roof driven ventilation.
The question is also - if I open the windows as soon as I get in, drive with all windows open for 1 min while already having the AC on how fast can I reach 125 F and how much fuel/energy would that require. Would that be compensated by the extra $$$$/€€€€€ (exactly 1000€ in Germany and you need to drop the 17" alloy wheels - I have no clue why...) one has to dish out for the sun-roof option?

I'll let you know the temps soon. I agree that 125 isn't too bad, but I hope it is better when I get a heatshield to block the sun shining through the windshield (I park facing south). Normally I would get in my previous car under the same conditions (2005 Corolla) and it would be extremely hot and would take a good 5 minutes, perhaps more, of full AC to make the temp in the car bearable. So I think the solar panels will reduce use of the AC.

But one more thing we shouldn't forget: the solar roof is also a plain old sunroof. And that is a nice option in and of itself.

I had my doubts about the SR at first, but with guidance from my salesman & folks at PriusChat I have learned a couple of tips that made a BIG difference.

1. GET A HEATSHIELD!
2. Crack all the windows about an inch or so.
3. Use the SR in conjunction with the remote a/c, which is how it is designed to be used.
4. Ambient means "close" and that's exactly what happens. Don't expect the same int/ext temp. It's not going to happen.

Pre hints I was having a temp difference of 25-30°. Post hints my average temp diff is around 10-12°.

I keep a digital thermometer in the center console, out ot the sun and ramdomly take a temp reading when I enter the car. Then I look at the outside temp after the car is turned on. The other day it was 91° outside and the interior temp was 99.4º. Not bad IMO.

Because the SR fan doesn't turn off until the car is in READY, put your hand in from of the vent and wait for it to cycle on. Depending on the how hot it is compared to your body temp, it should feel slightly cool. In mid 80°s to low 90°s it is actually a comfortable temp.

I am having a blast with the SR. I would recommend it to anyone. It also looks really cool.

It's probably higher than most SR III-IVs simply because the car is black.

Oh, I forgot one other thing - make sure the SR is closed and the interior roof panel is also closed, otherwise the sun just beats down on the interior.

Good point 32kcolors. Mine is silver, which would most likely make a difference.

Anyone with tinted windows and a HeatShield (no sunroof) want to run the same test?

For those of you who are incredulous at the temp w/ the solar panel working, do this little test. Get a outdoor thermometer for your back porch or whatever from the local garden center that hopefully goes up to at least 150 degrees. Stick it in your Prius so the sun is not directly hitting it but you can see it from ouside the vehicle. Leave it outside in the sun with all the windows rolled up tight. Go take a hike for a couple of hours and come back and freak out when you see it is buried past the needle! Cars get way hot inside!

This is why dogs and sadly some children DIE inside cars when its only 85 - 90 degrees outside!

The solar roof keeps the temps 20 - 30 degrees cooler inside than if you didn't have it. You might say, whew, 150, that is so much better than 180 but when your car cycles through that over many years, the interior will be in much better shape long term with solar than without, not to mention the potential fuel economy savings from not having to cool the dash, seats, center console, etc. down from 180, which takes longer than just the air!

I have a white V with no sunroof (obviously!!) and tinted windows (VA legal) and a toyota heatshield. I will do the sun test and get back to you. (once it stops raining here!!).
I should have done it yesterday....as it was 98 degrees!!!

Yup, always slide the panel shut and face the rear of the car toward the sun.
.

I have the same car Black Ext/Misty Gray Int, Solar. live in Orlando, and got the windows tinted w/30% tint. The fans are running when I step in the car but the car still registers 125-130deg when the outside air is in the mid 90s as measured with a cooking thermo sandwiched between the visor and roof. The remote A/C does help but wish they had a alarm clock/timer to set its start time by instead of a remote where you have to be in range of the car. Luckily I can start it by going to my office window 3rd floor. Quite curious in your results I have been tracking mine now for 3 days. Still glad I got the option as I like driving with the roof open in cooler weather but do question its effectiveness. Will try the heat shield tip or get clear tint for the front.

AlexT, I have not been able to remotely start my AC from a first floor office window. The window does not open. Are you opening the window? Thanks

can the solar roof be tilted up? cause that will vent the heat w/o allowing direct sunlight in (something I had to do on my black on black avalon)
some larger (aka panoramic) moonroofs cannot tilt, like my mom's 2009 forester

Seems like a waste of money... but if you are happy

No, but you can carefully position the car to maximize sun angle!