[SECProto]

That would explain why Solar City has thus far failed to account for the significantly reduced amount of solar energy that reaches Mars. Solar cells can't charge EVs fast enough on Earth. With the same panel area, it would take most of a Martian year to charge a single EV on Mars.

What are you talking about? Solar can charge an electric car just fine. Take desired charge rate in kW, divide by nameplate power output of panel, and that's how many panels you need. If you live somewhere with constraints on solar input (eg reduction due to clouds, distance from sun, or night) then you can increase the panel amount, maybe add some stationary batteries to timeshift the input.

Edit: not meant as a personal attack at all, but noticed your other comments around the thread are loose enough with the facts. Musk could learn a thing or two :)

[reitzensteinm]

Your edit is very rude. If you're going to call him out, you should at least take the time to give an example.

[SECProto]

Their profile says they don't read comment threads after 4 hours, so I didn't think they will see. But my mention of "being loose with the facts" and "Musk could learn a thing or two" was referring to another post of theirs where they said:

There have been [...] quite a few articles about Boring Co's liberties with the truth and its outright lies to the people in the neighborhood where the tunnel is being built - https://news.ycombinator.com/item?id=18704761

I thought this was, itself, misleading - I follow the Boring Co pretty closely, and I only saw one negative article re: the local neighbourhood around the test tunnel - and said article was mostly raising the plight of the locals with the airport/highway/industrial activity in the area. The Boring Company was only attacked as a bit of a bogeyman.

Combine that with this sentence in their original post, which I did already call out for being flagrantly misleading:

Solar cells can't charge EVs fast enough on Earth. With the same panel area, it would take most of a Martian year to charge a single EV on Mars

The only way I can see that being true is if it's talking only about solar cells on the roof of the vehicle (which no one technically minded should expect to power a car).

[gamblor956]

https://blog.pickmysolar.com/how-many-solar-panels-does-it-t...

From a pro-Tesla site. It would take 75 solar panels to charge a single Tesla in a day. Max theoretical efficiency on Mars is roughly 1/15th of Earth norm, not taking into account Martian weather, and assuming you are always somehow directly facing the sun the entire Martian day. Take weather and the day-night cycle into account, and it takes about a Martian year to charge one Tesla.

Google is your friend. A single search on Boring Co shows at least a dozen articles about their misrepresentative claims, so I assume the Google personalization filter is effecting both of our search results.

[SECProto]

Hey, thanks for the detailed response. My original post was calling out your original point: "Solar cells can't charge EVs fast enough on Earth". It seems you now agree with me:

"It would take 75 solar panels to charge a single Tesla in a day."

So indeed, you can charge EVs with solar panels, you just need more. 75x250W panels can charge a 75kWh model S in one day, on average (equals 135000km/year). Such panels are available at consumer prices of $1/watt including charge controller, so ~$20,000 would buy me the panels I need to fully charge my car daily (4 times as much as I need).

Max theoretical efficiency on Mars is roughly 1/15th of Earth norm, not taking into account Martian weather, and assuming you are always somehow directly facing the sun the entire Martian day.

These variables (martian weather, facing the sun) are similar to the issues faced on earth with solar panels. And the solutions are the same on mars as on earth: increase panels (aka overprovide) and include power storage, or include an alternate power generation system. Ideally both. Where the weather can have longer impacts (eg dust storms), an alternative power gen system (i.e. nuclear) is likely better from a launch mass point of view, but that isn't clear without doing the detailed math on it. That's before even getting into details on how different a vehicle on another planetary body would be (eg the lunar rovers had an 8.5kWh batteries and lasted multiple days - lack of atmosphere and lower speeds and mass make a car much more efficient)

Take weather and the day-night cycle into account, and it takes about a Martian year to charge one Tesla.

(or half a year if you double the panels, or a day if you have 365x the number of panels, or....)

A single search on Boring Co shows at least a dozen articles about their misrepresentative claims

If by "misrepresentative claims" you mean missed deadlines and abandoned ideas - I'd agree with that. Tunnel opening delayed, further extension of test tunnel dropped in favour of full network at undefined future date. But that's par for the course with everything SpaceX has done (eg Falcon Heavy delayed 6 years, Dragon Crew delayed years, BFR changing plans every time it's talked about), and shouldn't be even a bit of a surprise for anyone who follows Musk. As a member of the public who couldn't invest in SpaceX or the Boring Co even if I want to, those things really don't affect me in any way - the goals remain the same, and the progress remains ...progressive.

I assume the Google personalization filter is effecting both of our search results.

Agreed.

[gamblor956]

We don't agree, but that's probably because I left some assumptions implicit in my earlier comment.

At an average size of 65x39 inches, 75 panels is more panels than most residential properties can fit; you would either need a mansion or a commercial-sized property. I should have been clearer on this, but assuming the number of panels that the average house can support (5-10), you're looking at a week or two to charge an EV by solar panel at the typical Southwest residence (longer, outside of the Southwest). Assuming the same solar panel area on Mars gets you to the Martian year.

As for Boring Co, I'm not referring to the missed deadlines, but to their claims that they wouldn't be tunneling under people's properties, and that it wasn't a backdoor attempt to avoid environmental review, and their liberties with capacity numbers, costs, and numerous other claims they've made in their short corporate lifespan.