General Discussions

[northernblue]

Just to back up slightly Krudds, look up the world solar challenge:

https://en.wikipedia.org/wiki/World_Solar_Challenge

It’s been held every few years since the early ‘90s.
Solar powered cars start in Darwin and “race” to Adelaide, with the winners usually sitting on the speed limit most of the way for 3000km.
What originally started as freaky solar panels with wheels has become almost mainstream looking vehicles, so what you are proposing IS doable but probably not very practical with “a couple of kings panels and an old battery from the shed”

[LP]

What originally started as freaky solar panels with wheels has become almost mainstream looking vehicles, so what you are proposing IS doable but probably not very practical with “a couple of kings panels and an old battery from the shed”

The whole battery for a Solar Challenge car is limited to 21kg.

A small EV like a Tesla S weighs 2200kg and the battery is about 600kg alone, batteries for a 4WD EV are likely to be twice the weight, power/capacity basically scales with weight.

A Tesla probably consumes more power than a Solar Challenger just by booting the cars computer!

The NT is selected for the Solar Challenge due to the long straight mostly level roads and plenty of sun, years ago I watched a talk by one of the competitors and he mentioned that the car took kilometres to gradually accelerate to full cruising speed because the motors are so low power. During testing he mentioned someone loaded the bearings with the wrong type of grease, they used steering column grease instead of the special wheel bearing grease, and it destroyed the whole vehicles performance. I suppose that is a side effect of performance designed around low friction and low aerodynamic packaging.

[DJC]

The whole battery for a Solar Challenge car is limited to 21kg.

A small EV like a Tesla S weighs 2200kg and the battery is about 600kg alone, batteries for a 4WD EV are likely to be twice the weight, power/capacity basically scales with weight.

A Tesla probably consumes more power than a Solar Challenger just by booting the cars computer!

The NT is selected for the Solar Challenge due to the long straight mostly level roads and plenty of sun, years ago I watched a talk by one of the competitors and he mentioned that the car took kilometres to gradually accelerate to full cruising speed because the motors are so low power. During testing he mentioned someone loaded the bearings with the wrong type of grease, they used steering column grease instead of the special wheel bearing grease, and it destroyed the whole vehicles performance. I suppose that is a side effect of performance designed around low friction and low aerodynamic packaging.

You do realise that the solar challenge route is from Darwin to Adelaide and there are plenty of steep grades on the route.  Bad weather has played a role in several challenges with vehicle being blown off the road and running out of power because of overcast conditions.

The Cruiser Class vehicles have no limits on battery size and are permitted to use non-solar sources for charging.  They must complete a 1,000km stage before recharging from non-solar sources.

[LP]

You do realise that the solar challenge route is from Darwin to Adelaide and there are plenty of steep grades on the route. 

Sure we get that, but it's nothing as a percentage of the total route, gradients on the Solar Challenge are like a chicane on a F1 track.

For reference, we were talking about the use of portable SolarPV to recharge / power a commercial EV, and I was commenting in context of [member=20]kruddler[/member] discussing Off-road / Off-grid applications.

The Solar Challenger Cruiser class is basically an open class being recharged at various grid or fuel power recharging centres, although they are great pieces of technology demonstration they are not that relevant to a discussion about EV with portable SolarPV recharging. The Cruiser class has been dominated by universities sponsored by big industry or big R&D entities some vehicles are worth million$, the GaAS SolarPVs used in that challenge are so expensive they are normally only used in space. Even in this open class, the cars are a fraction the weight of commercial EVs, about 25%.

btw. Those bespoke GaAS panels, that make 800W/sqm, they aren't 10x or even 50x the cost, they can be 500x the cost of silicon. The reason why silicon is dominant despite on average being about 50% less efficient than GaAS. GaAS is also used in semiconductors, the unit cost of GaAS devices even at the mass scale of transitors (FETS, etc..) is about 10x the cost of silicon.

[kruddler]

Just to back up slightly Krudds, look up the world solar challenge:

https://en.wikipedia.org/wiki/World_Solar_Challenge

It’s been held every few years since the early ‘90s.
Solar powered cars start in Darwin and “race” to Adelaide, with the winners usually sitting on the speed limit most of the way for 3000km.
What originally started as freaky solar panels with wheels has become almost mainstream looking vehicles, so what you are proposing IS doable but probably not very practical with “a couple of kings panels and an old battery from the shed”

I remember that stuff from the 90s and i'd hardly call them cars. From memory they are very much lightweight cocoons wrapped in solar panel. For aerodynamics and weight saving, they usually were 'piloted' by kids laying flat.

[ElwoodBlues1]

I remember that stuff from the 90s and i'd hardly call them cars. From memory they are very much lightweight cocoons wrapped in solar panel. For aerodynamics and weight saving, they usually were 'piloted' by kids laying flat.

You are right they were nothing like cars, they looked like baby air gliders on wheels with a little cabin on the front and the back was like a wide wing solar panel configuration. The driver would have to be jockey size and would have boiled alive in such cramped conditions.....

[northernblue]

Yet if you look at the cars now they do at least resemble cars.
They are after all, cutting edge technology demonstrations not retail vehicles.

[ElwoodBlues1]

Yet if you look at the cars now they do at least resemble cars.
They are after all, cutting edge technology demonstrations not retail vehicles.

NB..With his clever marketing I think Elon Musk has created an expectation with his worldwide best selling cars that EV's have to have that futuristic look and a high tech name to go with it....My fav is The Cyber Truck that has both the look and name that makes you think you have stepped into the future even though I believe it already has a rust issue ?.
https://www.motor1.com/news/708690/tesla...drag-race/
Looks like something out of a Mad Max film....

[northernblue]

NT...With his clever marketing I think Elon Musk has created an expectation with his worldwide best selling cars that EV's have to have that futuristic look and a high tech name to go with it....My fav is The Cyber Truck that has both the look and name that makes you think you have stepped into the future even though I believe it already has a rust issue ?.
https://www.motor1.com/news/708690/tesla...drag-race/
Looks like something out of a Mad Max film....

Agree it’s pig ugly.
Apparently it’s also RAM sized which disappoints me greatly.

[LP]

If you want to see how an EV should look on the outside, at least in my opinion, do a search for some of Henrik Fisker's vehicles.
Fisker Karma
Fisker Revero

In fairness, Fisker has similar problems to Tesla with the odd vehicle randomly igniting unexpectedly, but that's all about making batteries not the technology.

Tesla promised the EV apparatchiks Self-Driving with interfaces that looked like an iPad, but it has never really eventuated and my understanding is they are still a ways off, a bit like Nuclear Fusion. Actually it appears the Self-driving stuff is going backwards with several early adopter regions now banning them after unusual accidents caused by Tesla, GM, Google and a bunch of others self-driving fleets.