Okay quick update. Looks like the solar roof isnt even charging the battery when in deep rest. See photo of voltage being only 12.2-12.3V overnight. Car has been in direct sunlight from 8am - 11:30am Again no obstructions to the solar roof outside. Then when i turn on the car and go to the solar tab, states 0 Wh generated today but now registering 65watts and the watts generated rose to 1Wh in the short time the car was on. Suspect ill have to take it to a dealer or something. Sorry about the broken images, im not sure how to remove them from the post.
Yesterday I finally brought it to service. I wrote an update last night. Couldn't find this thread, so started a new thread in the charging forum. I don't think many saw it, so I will paste in the main part of that post below: ------------------------------- I finally brought it to Toyota Service this morning, Marina del Rey. I spoke to the rep there late this afternoon. She said they left it out in the sun, and that the tech there said it did charge, added .6 of a mile of charge during the day. She said that tech will go over it with me tomorrow. (She said they checked with Toyota and .6 of a mile is normal!) I have noticed before there is something in Settings called "Solar Charging". When I looked at that before, it did show it was adding charge. Yet in reality it was not, as the EV miles on the main screen had not gone up at all. So I am guessing the tech looked at that screen and thought the solar charging was working, whereas in reality no EV miles were added. (besides, .6 of a mile per day is much less than the 3 or so miles I got before) (But again, lately I have left it multiple days in the sun and seen no increase at all in the EV miles left on the main screen.) Any suggestion for discussing this with the tech tomorrow? I will not accept being told the solar charging is working, when it actually has not worked at all for months? Does anyone understand that screen under Settings, that may show that the solar is adding charge, when I see no actual charge added in the EV miles listed on the main screen? Thank you in advance for any input. (Except for the guy who always writes that the solar charging roof is worthless. I don't need that input. I know it charges much slower than being plugged in, but the few miles per day of added charge while sitting in the sun was worth it to me before. Now not working at all.) Thank you for any real insight, and suggestions though, Thank you,
see previous message Note the following article: It says the solar roof could add up to 6.4 miles of charge daily when parked all day in the sun! I never got nearly that much (more like 3 miles), although as said, nothing at all in recent months. (although parked in bright sun). (How much have others usually got?) So BS for that service dept to tell me that mine does work, that parked all day in the sun there today it added .6 of a mile charge, and that that is all it is supposed to add! See the following article: Is The Prius Prime's Solar Roof Worth The Extra Cost? I would still appreciate any tips on dealing with that service dept. tomorrow!
I can leave the car a couple days (so far yesterday and today), but not several. They don't give loan cars. I was told that yesterday (a ery sunny day, and parked in direct sun) that the charge increased .6 of a mile. Totally insufficient amount, and besides, I have not seen any increase at all for months. So I don't think they determined it from the EV miles number on the main screen, but somewhere else, like that Solar page one can find in Settings. (As said, I have looked at that page before, and is hows that the solar roof is adding charge. Yet when I look at the EV miles on the main screen, no increase at all.)
Have you got assistance from them, when a dealer service dept. has not helped? I was told that the service tech called Toyota yesterday.
See previous new messages and replies, added today. In asking ChatGPT about it,following is its summary: Practical Summary If you park outside all day in strong sun and don’t plug in overnight: You might see ~3–4 extra miles of electric-only range added that day. On exceptionally good sunny days, ~5–6 miles isn’t unheard of. On cloudy or partly shaded days, it could be lower. So yes, I used to get about 3. Now none at all. So their (service dept.) telling me it is fine doesn't solve the problem?
In a text discussion the rep at Toyota Service wrote to me: "FYI, the EV display will is not the number for the proper solar charging system. Usually The solar roof only trickle charges the auxiliary system or slowly add interview to the traction battery in the background." Clearly not true. My EV miles used to go up about 3 miles daily when parked in the sun. Per the article above, it has been tested as going up to as much as 6.4 miles.
As I just texted to the rep: "Page 136 of the car's manual, in discussing the solar charging roof, says: "the hybrid battery (traction battery) is charged while parking". That means EV miles. And as I told you, it did add EV miles before. Now it does not."
FWIW: Sorry, you need to LOGIC this out, rather than searching the internet for "supporting evidence". I could find evidence that the world is indeed FLAT on the internet. That doesn't mean it's true........... I believe that solar roof is rated at 180W output - that's under ideal conditions. How many miles are you getting per KwH?? My car is averaging 4-miles/KwH; so 6.4/4=1.6KwH. So your panel needs to have optimum generation for 8.89 hours to achieve that. Well it's winter and the sun is only up for 9 hours and low in the sky. That's assuming your currently achieving 4 miles/Kwh. I just did a 140 mile round-trip and the gauge is reading 3.5 miles/KwH on my lighter, smaller gen4 Prime. I'm pretty sure the dealership will listen to logic, rather than internet dribble.......... Just my two cents.......
Sorry, I don't know about kwh. I know that the car used to add a few EW miles of charge each day parked in the sun. As it is supposed to. Yet for the last couple months none at all. That is enough to tell me something is wrong, without needing to know about kwh. What you just wrote is on the Internet. So ignore it as "Internet Dribble"? I think it can be useful to hear experiences from other users though? Do you have the solar charging roof? I shared a link to an article about the solar charging roof. So is that "Internet Dribble", while this forum is not? I also quoted from the car's manual. Ïnternet Dribble"?
There must be a few others with solar roofs on this forum. I wonder if theirs are still working in the winter with low sun angle (small cos(theta)).
Hint: it's in one of your menus options. The dealership will start charging you diagnostic fees, because you don't know how your car is suppose to work and they can't find anything wrong every-time you bring it in. You need to articulate to them the actual problem your experiencing, otherwise no error codes no service.
It is also certainly possible that the solar computer is acting up, as the owner’s manual mentions. Perhaps wait until around the summer solstice, and if it’s still not working under intense sun, have it repaired.
I believe I'm experiencing the same thing as you. During the summer when I got in the car after being parked at the office all day it would say 3.5-4 miles of range added that day (I got around 4 miles/kwh during the summer). I seem to recall towards fall time it did drop off a fair amount, but as of recent now that we're mid winter on a rare sunny day it's saying I haven't accumulated anything when I get to the car after sitting at the office. Then when I power the car on I do get a wattage reading. I had just chalked it up to being reasonably far up north in Northern Oregon and the angle of the sun at this latitude wasn't enough wattage to hit some threshold needed to start storing the energy. Maybe the energy its getting below that threshold is going to power something else? I got my car mid summer this year so this is my first winter. It's well within warranty period so my current plan is to wait till spring to see if I start accumulating range again. I'm not raising alarms yet, but since it's happening to someone in SoCal I'll be watching this thread pretty closely.
Here is the solar-position calculator. The cosine of the solar zenith angle is the factor that multiplies the solar radiation. You can calculate that factor at different locations, days, and times. See how it varies by the hour and day at your location. In reality, it will be a lot worse than the cosine of the zenith angle. In fact, it will be worse than the square of that angle, as a higher angle also results in the solar panel being hit at a higher angle. which is an additional cosine factor, and the sun’s rays are passing through more clouds and humidity. This is in addition to the cosine factor that results from the rays entering the Earth at an angle. So, expect only about 10% or less sun radiation being received by the solar roof in the winter. That explains why it stops working in late fall. NOAA solar-position calculator
don't forget that you'll also have to compensate for cloud cover too. It's only 180W panel and your burning kilowatt/hours - so generating 180W in one hour is the best you can hope for - assuming no lost in the conversion and managing electronics. 3-4 miles seems reasonable for a sunny cloud free day in the summer. If you want to get your 6.4 miles; you can move the car down to the south pole in the winter and then the north pole in the summer. 20+ hours of exposure.
Yes, I explained further that in the winter, you would be receiving no more than about 10% of what you are receiving in the summer, even on a perfectly clear day. That’s probably not enough to turn on the solar-roof computer. Therefore, it is unlikely that there is a malfunction. The solar roof only seems to work during the summer, late spring, and early fall.
