At least we agree on our dislike of Prius's. But they are a convenient example to use so lets not get carried away.
The solar on the Prius Prime is actually only 180W. That is where the 3.7 mile/5.9 km comes from.
There was no way your estimated 0.6kW could fit on that roof, which is the only reason I suggested they might be using high efficiency cells. Edit: Misread by me.
And sorry, there is no way that the price is locked in at $2500 for only 180W using bog standard solar cells. Competition will fix that, and it will take time.
And the engineering point was about the solar roof failing the rollover test in the US. That part is clearly not sorted.
It is obvious it needs to be mass produced. The price will drop and then the collective power of all of the solar together becomes significant.
I don't dislike Prii per se, I just know the drivers. I don't know where you got 0.6kW from, I had previously referred to 0.6kWh/day. Everything else is just rough guesses. But I have to ask--when you say significant, significant to whom and compared to what?
Yes I read your comment too quickly and thought you had proposed 0.6kW as the panel capacity of the prius instead of the kWh generated by the panels per day. Took me a while to realise my mistake. My bad.
It has been well documented here that one small solar panel on an EV generates a rather insignificant amount of energy every day.
Now consider the number of EV's being produced per annum. Even the small amount of solar generation on each adds up to a significant total amount. That was what I meant by significant.
As to who would be interested, well that is above my pay grade, but logically I would think it would be of interest to governments and the electricity authority responsible for planning.