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Serious questions about the solar option available in the Prime:

Discussion in 'Gen 5 Prius Main Forum' started by NonFormulaic, Aug 14, 2024 at 8:19 PM.

  1. NonFormulaic

    NonFormulaic Member

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    My Prime XSE Premium with the solar option is due shortly. Very glad to NOT have the large non opening moonroof as the So Ca Desert has been averaging 113 degrees this summer. That said, I'm wondering if the solar panels on the roof will generate interior heat? Separately, are there additional batteries which might require replacement or service? There’s very little information available on the Prime solar option. Any help on this…especially from XSE Premium with solar drivers, would be much appreciated….thanks!
     
  2. hill

    hill High Fiber Member

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    Not only do black car surfaces (including pv panels) increase cabin heat when left in direct sunlight, but in addition to that - for every degree above 77°f that temperatures increases, your solar panels will lose approximately 0.35% in power production efficiency. Put another way, for every 3°f, you will loose a little over 1% panel efficiency. AND THAT's in the shade. It doesn't even account for DIRECT sunlight on solar panels, which will easily bring your panels (on a 113°f day) up to over 150°f. At that junction, your little roof panel on your car will have lost over 12%.

    Solar Panel Temperature Range Explained

    Kind of makes one wonder it it'd be better to just get white cars for extreme heat environments.
    .
     
    Trollbait and Merkey like this.
  3. PriusCamper

    PriusCamper Senior Member

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    I don't know, but I can tell you that in Gen3 the solar roof option powered fans to keep the interior cool when you are parked in a parking lot and not much else. It would be safe to assume that Gen5 won't be very much further advanced than that because you can't do much with the small amount of solar electricity you can generate from the roof of a car.
     
  4. dbstoo

    dbstoo Senior Member

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    It might be safe, but it's not based on published information from Toyota. Somewhere on this board is a thread there it states the approximate charge rate when parked in a sunny area. At the time, I figured that without plugging in it would cover my weekly errands of 3-5 miles every other day and the weekly trek to the bowling alley one town over.
     
  5. NonFormulaic

    NonFormulaic Member

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    Sounds like a gimmick…..wondering if there’s anyone who has hands on experience with Prime Solar? Additionally, how effective is the sunshade for those equipped with moonroof? I’d like the XSE Premium without the moonroof. Only way to accomplish that would be with the solar option. And that’s the main draw for me.
     
  6. dbstoo

    dbstoo Senior Member

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    It does not need to be a gimmick. If you consider that the Prime gets around 4 miles per kWh and that many errands consist of a few miles driving interspersed with an hour or so parked, there are circumstances where a lightly used Prime could recharge fully during the day.
     
  7. hill

    hill High Fiber Member

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    no it doesn't HAVE to be a gimmick .... but under many if not most circumstances it is. Claiming how efficient its solar panel CAN be - does not mean that it's usually in optimal conditions (see post #2). To be optimal, you'd have to have the most direct sunlight. Do you live in bogota? Singapore? Nairobi? Those places are not too far away from the equator - where the sun's azimuth is higher during most daylight hours. But then they're very hot so you have to subtract efficiency for heat. When driving around for work & errands, do you park under trees? Covered parking lots? Near tall buildings? Major cities like Minneapolis, New York, Detroit, boston, Cleveland, Seattle - during much of the year the azimuth is less than 45° ... far from ideal sunlight - & that doesn't even account for cloudiness.
    Realistically (again, presuming you aren't a shift worker - graveyard - swing shift, where your car isn't in a garage while you're asleep) - most will at best get a mile or 2 of range - in summer only. Average being 1½ miles in summer .... 1,300ish yards one way.
    Technically Toyota charges $610 for the solar panel. Average cost for electricity per kWh in the USA is currently (no pun intended) 15¢. Most utilities give a big break if you charge off peak. For example our off-peak is only 9¢. But rounding up to 10¢ off peak? .... how many kWh's would those 10¢ kWh's buy, if paying $610?
    You could pay for 6,100 kWh. or
    put in terms of mileage - that's over 24,000 driving milea (at 4mi per kWh) ... BUT you can't just buy the solar panel because it is always bundled with other stuff you may or may not want to oay for - which means you're going to pay over $1,000 for the panel bundled options - so it is going to make that 24,000 miles a WHOLE lot higher ... maybe requiring ~30,000 of driving.
    This isn't meant to bash PV. We installed over 8kWh on our roof. That's where it works best, because MANY utilities charge tiered rates where you can easily pay 40¢ - 50¢ per kWh & higher - and it drives those tiered costs down into the lowest tier maybe even zeroing out your costs.
    In short - YMMV

    .
     
    #7 hill, Aug 15, 2024 at 10:06 AM
    Last edited: Aug 15, 2024 at 10:28 AM
  8. Trollbait

    Trollbait It's a D&D thing

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    Or infrared reflecting paint Toyota felt wasn't worth offering in the US.

    Nissan is developing paint that goes a step further in producing electromagnetic waves that interfere with income light waves to reduce heat absorption.
    https://www.msn.com/en-us/autos/news/nissan-s-new-paint-uses-electromagnetic-waves-to-keep-temperatures-down/ar-AA1ot690

    The gen 4 Prime had a solar option that charged the battery when parked, and provided 12V power when in Ready. Didn't come to North America because the glass didn't meet crash standards. The price was probably also too high with out price of fuel.

    For the OP's questions, I haven't seen any in depth info for the solar system. It meets US regulations now, and that is about it. The gen4 had a battery cause charging it up, and then it dumping its charge quickly into the traction pack was deemed better. The gen4 also have the traction battery in a different spot that the hybrid's. In the gen5's cut away pictures, there didn't seem to be any space to house a battery for the solar system. The price also seems low enough to not have a hybrid sized battery added.
    It's a gimmick if the price of the system is more than the miles for gas or electricity provide. The gen4's was $3000 in Japan. There fuel costs more, and many wouldn't have access to home charging.

    The $610 for the gen5 might be worth it for some. Though it might be cheaper to simply wrap or paint the glass roof if that is the reason to choose solar. Or just get the XSE w/o the glass roof option.
     
  9. Hammersmith

    Hammersmith Senior Member

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    The sunshade seems to work fine, but I also live in a very different climate than you, so take it with a grain of salt.

    In the gen5, the solar roof works in two(/three) different modes:
    1. While the car is in Ready mode, it contributes to the 12V system. This takes part of the load from the A/C, water pump, infotainment, etc. off the traction battery, (slightly)increasing EV range while driving. This mode is also useful when you're trying to keep the cabin conditioned while using the ICE as little as possible(say you're living/camping in the car).
    2. While the car is off, it (slightly)charges the traction battery.
    (3. While the car is plug-in charging, the solar roof is disabled.)

    There are no extra batteries or anything that would require additional service. The panels will generate a small amount of additional heat, but the difference between that heat and the extra heat from the glass roof is likely negligible. Depending on where your car is parked during the day, I think you are probably the best case in the US for getting the solar roof option. You live in one of the sunnier regions in the US, and your temps are high enough that you'll be using the A/C often while driving. Are you ever going to fully recoup the $610 cost? Maybe, maybe not. But even if you don't, you'll come closer than most, and maybe the solar roof will be ever so slightly cooler in the sun than the glass roof.

    In other words, don't worry about your choice and enjoy your new car when it gets to you. :)
     
  10. KMO

    KMO Senior Member

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    There's no additional battery. There's a separate solar charging unit that directly charges the main battery or feeds power into the running system. That's mounted on the right-hand side of the cargo area floor, opposite the left-hand-side mains charger. You do get a teeny bit less storage, because the tray right-hand piece of underfloor storage EPP foam gets shallower.
     
  11. ken2023

    ken2023 Member

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    On very hot days here in New Jersey I use the sun shades sometimes when parking. The shades are a single thin layer of cloth in a frame, certainly not as insulating as a hard top with some layers between the sheet metal and the interior, and have a reasonable air gap between it and the glass roof. You slide them by hand. In most cars with a small sunroof or moonroof you'd usually see a more rigid multi-layer shield that is operated by a small motor and slides into the roof. There's no place for a rigid shield to slide given how large it is, so the cloth layer rolls up instead. But they do keep the interior noticeably cooler. And when driving they keep the direct sun off. I may not be in as hot a climate as you, but definitely happy with the glass roof, and in the back seat it makes a huge difference -- car feels more spacious. I'm usually driving with kids in the back. As for insulation though nothing I can really quantify.
     
  12. Hammersmith

    Hammersmith Senior Member

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    Are you positive about that? I think the foam inserts are the same for both the solar roof and non-solar roof PHEV. I think the non-solar roof PHEV just has a little extra wasted space under the foam. I don't have access to the parts catalogue right now(it costs money to access it in the US), so I can't confirm, but I thought there were only the four sets of foam(low floor, high floor standard, high floor spare, high floor PHEV).
     
  13. KMO

    KMO Senior Member

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    Yes. The foam for the PHEV is in two parts. The right-hand part has two variants for solar and non-solar. There's no change to the floor level, it's just whether the right-hand bit is designed to sit on the metalwork or go over the solar charger.
     
  14. Hammersmith

    Hammersmith Senior Member

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    Cool, good to know. I guess I missed that when I was looking over those part diagrams last year. Not surprising since they didn't apply to me so I probably just skimmed over them. Thanks.
     
  15. KMO

    KMO Senior Member

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    As it happens, still have an EPC window open despite my login having expired...

    upload_2024-8-15_18-6-53.png
    upload_2024-8-15_18-7-25.png

    (Part 64997 doesn't vary, despite it being shown again in the W(SOLAR ROOF) bracket).
     
  16. KMO

    KMO Senior Member

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    I'm now wondering about the "To 10/2024" on the RHD row. Never seen a future date before in the catalogue. Planned end of production? I don't believe any RHD countries in Europe are offering the solar roof, but not sure why they're distinguishing LHD and RHD in the catalogue here.
     
  17. Hammersmith

    Hammersmith Senior Member

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    Yeah, that doesn't make sense on its own. If you still have access, I'd cross check against the Japanese RHD model and see if that part also has a 10/2024 end date. And also look at the solar panel itself in the European section to see if the 10/24 pops up there.

    (I'm assuming you know how to change between regions in the parts catalog.)
     
  18. KMO

    KMO Senior Member

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    The solar control unit is shown with "to 09/24" for RHD in the European catalogue (and same part as LHD). I've not managed to find the actual panel. (They seem to be struggling a little bit to figure out where to file solar stuff.)

    Don't know about getting into the Japanese version - in the past I've only seemed to be able to get into the European version, and given that my login has expired that may be preventing me from "escaping" further too.

    Edit: Actually, okay, I can select region = Japan, but the G5 Prius seems to be missing from what that presents me with. Plenty of other cars, and other Prius generations, but no G5.

    USA does show me the G5 Prius, but with the wrong picture.

    And that then has a slight twist on the formula:

    upload_2024-8-15_18-52-8.png

    And the control unit as "to 09/24" for G.
     
    #18 KMO, Aug 15, 2024 at 11:47 AM
    Last edited: Aug 15, 2024 at 12:02 PM
  19. KMO

    KMO Senior Member

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    Ah, okay, the G5 is there for Japan if you search for MXWH61 - it's just not called "PRIUS". It's called "NEW MODEL (2022-)". :LOL:

    And no "To" dates there on the control unit or floor box.

    There was a change to the solar control unit in 07/2024 for all regions - substitute part numbers. Don't know why they're all different.

    USA: 894B0-47040 -> 894B0-47041
    Japan: 894B0-47050 -> 894B0-47051
    Europe: 894B0-47070 -> 894B0-47071

    So then 47041 is shown as 07/2024-09/2024 for G, or 07/2024- for H.

    So I'd say they're eliminating the solar production ability for options that may never even have been produced - RHD for Europe or mid-trim for USA.
     
  20. Hammersmith

    Hammersmith Senior Member

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    The gen5 in the Japanese catalog is just a red Toyota symbol with 2022- (I think) underneath it. I've always found it humorous that the gen5 got so screwed up in the parts catalog: Japan put a placeholder image in and forgot to update, US accidentally grabbed a gen4 image instead of the gen5 then made it worse by also putting a gen5 image that links to either the European or rest-of-the-world version, and Europe actually got it correct from the start.

    edit: You found it before I finished my post. lol