On top of cars is probably the second-worst place to put a solar panel, just after on the road itself (I say this after having participated in building a solar car). It's extremely difficult to get solar panels to work efficiently in that environment, they're almost never pointing in the right direction, they are frequently shaded (even partial shade will wreck the efficiency of a panel). You're much better off putting them at the charging points.

That has to be a typo and the real number more like 10kw - 1kw is 1.3HP, lawnmower engine territory.

1kw to maintain 5kmph perhaps. To maintain 100-120kmph a car needs around 20kw. The first gen EVs like Renault Zoe have a ~24kwH battery and a real world range of ~100km.

These numbers don't pass the sniff test, the World Solar Challenge wouldn't be a thing if it were that easy.

Model S has about 500 kW, Model 3 300 kW, Bolt 150 kW, Renault Zoe like 50 kW.

As for the other question, the solar panels provide way too little charge for the given area. When EVs are all about to have 100+ kWh batteries soon, it doesn't make sense to have a solar roof top:

https://www.engineering.com/ElectronicsDesign/ElectronicsDes...

The numbers in that article seem chosen as low bars to prove a point. There are panels with much greater efficiency/density and lower cost. If it doesn’t make sense today it will in the future.

If a company could move their trucks for “free” for 5 hours/day they would.

> There are panels with much greater efficiency/density

Not by a huge amount. You could get 3x that with just about the best solar panel, but they didn't appear to factor in the losses from having the panels facing up-ish and not toward the sun, so you also lose another big chunk of power.

> If it doesn’t make sense today it will in the future.

Doubt it. Solar panels can only be so efficient.

> If a company could move their trucks for “free” for 5 hours/day they would.

Sure, but we're looking at more like fifteen minutes.

Put the solar panels on the ground. They'll give you more "free" range, with less effort.

I'm not completely discounting it, but 5h seems like a lot for trucks, even if you have more roof area. Tesla's Semi has a 1 MWh battery, which will be drained within a day by most firms, and I imagine Semi 2.0 will have a 2MWh battery. It's hard to imagine the solar panels would keep up with either of them.

Even if the panels can generate 100 kWh a day for the trucks, that's still like 1/10 of the day, so more like an hour. But 100 kWh seems really unlikely, even in the future.

1kW to maintain is nonsense. My 11kW limited motorbike (much lower air resistance) can barely do 65mph, sometimes hits 70 on a downhill. Any wind and you won't break 60.

This would also a good idea for countries like India where the sun mostly shines and the electricity grid is weak.

Priuses have a solar panel on the roof, but all it has the capacity to power is a fan to keep the cabin cool when you park in the sun on a hot day...

That's the old version; they're claiming the new can add 3.7 miles of range for each day of charging.