Vehicle color

Aptera Community Aptera Discussions Vehicle color

Aptera Community Aptera Discussions Vehicle color

  • Vehicle color

     John Malcom updated 2 weeks, 1 day ago 15 Members · 22 Posts
  • Leo

    Member
    November 20, 2021 at 3:15 pm

    I love the look of black, but is it a good idea? The temperature difference between white and black while sitting in the sun is pretty significant. Since the body is used to dissipate heat while driving, would color choice effect it’s performance?

  • BRUCE MENGLER

    Member
    November 20, 2021 at 3:31 pm

    I understand the reasoning behind the question.

    I will respond with a different question.

    Given the egg shape of Aptera, how much of the car surface below PV cells will actually be exposed to direct sunlight?
    I contend that a majority of the vehicle below the PV cells will be in the shade of itself.

    • Leo

      Member
      November 20, 2021 at 3:49 pm

      Thanks. I had considered that logically. If the body acts like a heatsink, a lot of that heat would spread. Not sure how much difference it would make though.

      • Riley -_-

        Member
        November 20, 2021 at 6:37 pm

        All white top or white between solar cells might be an important modification for owners in hotter climates.

        • Curtis Cibinel

          Member
          November 20, 2021 at 6:45 pm

          Great concept but quite likely the hatch isn’t wrapped in black and is instead glass and a material color. I have to think the black top wasn’t entirely a style choice as overheating the solar wouldn’t be a functional choice. If they can make things work with clearcoat over the polycarbonate color (instead of wrapping) I’m sure they will.

    • Paul Schultz

      Member
      November 21, 2021 at 6:41 am

      Bruce, unfortunately, the solar panels are going to absorb a lot of energy and will heat up the surface below them. I have flexible solar panels on my travel trailer. Before I installed them I investigated how to place some sort of buffering material between the panel and roof of the trailer. Other trailer owners have taken infrared temp readings of the interior ceiling of their trailer and the temps are very elevated where the panels are located. My trailer is a high-tech construction with a honeycomb ‘sandwich’ construction. Not identical to the Aptera but analogous. The panels heating a parked Aptera is going to be an issue to address. Here is a picture of a traditional RV roof showing the scorch marks left by a standard flexible solar panel. Note that you can make out where each cell was located.

      No matter what we want to believe regarding maximizing solar charging. On a blazing hot summer day I predict Aptera owners will opt for the shady parking spot just like any other vehicle owner.

      Paul

      • Oz Man

        Member
        November 21, 2021 at 7:07 am

        Paul, I will wait and see how it works out, but the composite shell that is below the roof solar panels is not like your trailer. With its filled construction, it will likely offer far better insulation that should be well able to overcome additional heat from the panels, which will also be powering interior cooling fans to keep the temperature down.

        • Paul Schultz

          Member
          November 21, 2021 at 7:51 am

          I believe in the case of my travel trailer that it could dissipate passive solar heat better than the Aptera skin. My trailer has an “Aptera-ish” build based on aircraft skin principles as well. Lightweight honeycomb construction. The trailer skin is thicker, with more honeycomb air space, than what appears to be the case from the recent pics included in the November news blog posting on this site. I have a concern about the ability to keep the interior of the vehicle from becoming significantly heated when sitting out in the sun for most of the day. Here are two pics below. The first is the Aptera honeycomb design. The second is the Safari Condo Alto honeycomb design.

          Paul

          • Oz Man

            Member
            November 21, 2021 at 9:57 am

            Paul, sorry, for some reason I was picturing a cargo trailer when I was responding. Is the honeycomb on the trailer enclosed in aluminum/metal? The composite on the Aptera may offer insulating properties on its own, but still, will be a wait and see type thing.

      • Joel Smith

        Member
        November 21, 2021 at 11:12 am

        Extrapolating from deduction; seems to me that we are talking about two layers of material here. There is the structural composite body overlaid with the replaceable surface panels that will include the PV cells. The opportunity to keep the PV cells cool and to inhibit heat transfer into the cabin lies at the joint between the two layers. I imagine a bit of air gap or channels and naturally drawn air flow through them carrying away waste heat. That is if they are not deploying their active cooling system there already.

        • Paul Schultz

          Member
          November 21, 2021 at 2:01 pm

          I employed a similar tactic when I installed my flexible solar on my travel trailer. I used coroplast (plastic corrugated board) as an added buffer layer. I couldn’t leave the assembly open to airflow for fear of the panels lifting off over time at speed. But, the added layer keeps the hot panels lifted off the roof of the trailer. I suppose a method for providing some level of cooling to the underside of the Aptera solar assembly is possible. We will have to wait and see.

  • my_discord_number_is_0328 bloody stupid

    Member
    November 20, 2021 at 8:09 pm
  • Joshua Rosen

    Member
    November 21, 2021 at 6:33 am

    White in Texas, Black in New England. If you live in a hot climate than a white car will stay cooler, if you live in a cold climate then you want the car to get as much heat from the sun as you can. It’s the same color rules that you’ve always followed although more so in that the costs of heating or cooling are more noticeable in an EV because it effects range.

    • Lou Verner

      Member
      November 21, 2021 at 8:59 am

      White in Texas, Black in New England isn’t taking into account Winter vs Summer conditions. While TX undoubtedly has, on average, warmer temps regardless of time of year than NE, it can still get plenty warm in NE summers and one would still likely encounter warmer than desired interior temps if leaving car out in full sun. First run (non-custom exterior color) Apterae are all going to have dark colors on hood/roof regardless, so it will be up to owners to decide how to manage interior temps.

      • John Malcom

        Member
        November 21, 2021 at 9:41 am

        Good high level assessment Lou!

        I believe the wives tale is correct, but not to any meaningful degree.

        As a matter of full disclosure, I had to take Thermodynamics two times to pass in undergrad school then only passed with a C so not a great heat transfer specialist.

        Aptera indicates that the vehicle will FULLY function at temperatures up to 125 degrees Fahrenheit and will be tested to those conditions as a minimum as it is the general practice to engineer and test to a higher standard that advertised to insure under promise and over deliver or just make sure you meet you published value. These test results will be made public. With the cooling technology employed by Aptera, I see no circumstances where the ambient temperature would affect the performance of the vehicle as it is creatively and well engineered.

        I strongly believe in the effectiveness of Aptera engineering to address any heat exchange problem.

        I have not encountered any published test data that quantifies how much vehicle systems performance is affected based on color, shades of color, or type of colored surface. Additionally, accounting for the different shapes the vehicle may have, or the amount of surface covered by the different colors, the orientation of the colored surface to the sun, the time of year, and latitude of the vehicle location would have to be taken into account for an accurate assessment. It would take a pretty complex algorithm (Much more so than computed Cd) to calculate these values.

        Joshua, if you have some engineering test data to indicate otherwise, please share it with us on the forum.

        • Joshua Rosen

          Member
          November 21, 2021 at 1:26 pm

          Black absorbs heat, white reflects it. I’ve never lived in the South so my opinion about white cars doesn’t go beyond what the Car Talk guys used to say, when someone called in from Texas they would ask them what brand of white car do they own, sometimes the question was what kind of white Mercedes do they own. My personal experience with dark colored cars, my Tesla is black, is that it’s very unusual for them to get uncomfortably hot in the summer because we have trees everywhere that provide a lot of shade. AC costs very little range because summers are mostly in the low 70s, a couple of weeks a year it gets into the 90s. Winter cold has a tremendous effect on range so anything that helps to heat the car is welcome. That said if you live in a temperate climate pick the color that you like, even white, because it won’t make a big difference. If I lived in the Southwest I’d probably pick white and I certainly wouldn’t pick black, my experience of visiting the Southwest in summer is that the sun is brutal, but if someone with direct experience wants to weigh in I’d bow to their opinion.

      • Don Daniels

        Member
        November 21, 2021 at 5:45 pm

        Did I read somewhere that Aptera was going to use a small amount of the solar electricity to run a small exhaust fan to keep the interior closer to ambient temperature when it gets very hot inside?

        Also, since they plan to put solar panels on the dash, a full sunshade in the windshield would block that function.

    • kerbe2705

      Member
      November 21, 2021 at 11:31 am

      What Bruce Mengler said, above…

  • G Johns

    Member
    November 21, 2021 at 9:31 am

    I wanted the silver but it’s not dark enough for me so I might need to go with a custom wrap. I better start saving for the extra cost.

  • John Trotter

    Member
    November 21, 2021 at 2:55 pm

    I live in very sunny and hot California (Central Valley). I opted for the hatch solar cells because of the shade they will provide. Once all the top surfaces are either glass or solar cells, I can’t imaging the color of the rest of the Aptera mattering much. I like the black of Noir, but might still opt for custom color of some sort.

    • Joshua Rosen

      Member
      November 22, 2021 at 6:35 am

      I wonder how much cooling the solar cells will provide, perhaps a lot. Normally any solar energy that’s absorbed is turned into heat, thus the white vs black debate, but solar cells convert some of it into electricity. Any solar energy that’s converted to electricity is energy that’s not converted to heat. Just like regen braking reduces the amount of heat produced by the friction brakes the solar cells will reduce the heat absorbed by the car. For people in sunny climates that’s a second argument for maxing out the solar cells, the first being that you can actually get a significant amount of energy, the second being that the car will be cooler then without them given like for like color. When the car comes out someone should do a comparison of the cabin heating of a white car with minimum solar, a black car with minimum solar and a black car with full solar.

      • John Malcom

        Member
        November 22, 2021 at 7:54 am

        Good idea! do an experiment so we have some empirical data to make a judgement

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