from Hacker News

Show HN: I built a 4000 watt solar array on top of my Tesla (AMA)

by somid3 on 1/12/24, 2:20 AM with 19 comments

• by schiffern on 1/12/24, 5:29 AM

  Have you considered bifacial panels to get sunlight reflecting off the pavement? Depending on albedo it's perhaps (up to) 20% more power, but the panels weigh the same.

  For direct DC-DC charging you'll need to convince the car that it's connected to a Supercharger (or CCS1 via the adapter), causing the vehicle to throw the internal switch and directly connect the charge port to the battery. This is followed by continuous communication so the car won't throw a fault and disconnect.

  https://github.com/uhi22/pyPLC

  https://www.heliox-energy.com/blog/dc-charging-a-complete-gu...

  https://openecu.com/case_study/interface-evse-with-combined-...

• by thegrim22 on 1/12/24, 3:14 AM

  Am I missing something or are there no pictures of the 4000W version, only the 2000W version? The 2000W version's panels encompass the entire footprint of the vehicle so I'm trying to imagine how on Earth you could possibly double the wattage still.

• by eternityforest on 1/13/24, 5:25 AM

  If they covered the entire car with flex panels I'd expect a similar result, right? If it gets 20 to 60 miles a day that would seem to be proof that solar cars could be A Thing and people in certain places could probably meet almost all their needs with just panels.

  Really cool project!

• by j45 on 1/12/24, 6:40 PM

  I wonder if this kind of panel setup could be a trailer or hitch assembly that could be pulled. Maybe it has a battery on it too for charging on the go to get out to further places.

• by joesnark727 on 1/12/24, 3:06 AM

  I bought a 400 and a 100 watt suit case panel for my not yet purchased lightning/cybertruck. They just charge my fridge and tent a/c battery at the moment.

• by bilsbie on 1/12/24, 2:05 PM

  Amazing! Have you thought of commercializing this? In the long term as prices come down there’s no reason everyone shouldn’t have this.

• by ukuina on 1/12/24, 5:34 AM

  Not as ugly as I thought it would be!

  With some refinement and contouring to the body of the vehicle, this could make for a fully-untethered city taxi.

• by mentos on 1/12/24, 5:06 AM

  How long would it take to charge the car? I asked ChatGPT4 and got this answer:

  It would take approximately 2.5 days to fully charge a Tesla Model 3, which has a 50 kWh battery, using a 4,000-watt solar panel array under optimal conditions (assuming the solar panels operate at their maximum output for 5 hours per day). Keep in mind this is a theoretical estimate and real-world factors could affect the actual charging time.

• by 1970-01-01 on 1/12/24, 9:33 PM

  A small solar panel should be integrated into vehicles just to maintain the low voltage battery.

• by somid3 on 1/12/24, 2:25 AM

  If anyone has questions, drop here. If you know about DC charging an EV message me

• by arcastroe on 1/13/24, 2:15 AM

  Might as well do away with the glass roof though