Does the math check out? You would need about 10kW-h to get the claimed distance, times three for the efficiency (by the way, there are NO mass-produced cells with 34% efficiency; they must be using GaAs or multijunction cells to achieve 34%) means solar input of 30kW-h per day. The projected horizontal area of a Prius is 8m^2 (including the windows) so we need about 4 hours of 1000W/m^2 insolation. Which I guess isn't totally impossible. Typical average insolation at populous latitudes is around 200W/m^2.
And then you have to figure, if you took the $ and mass budget of the solar cells, could you just make the battery pack a little bigger/better instead for the same or more gain? Keep in mind the gain would be more reliable. You wouldn't have to depend on sunny days, and sunny parking spaces.
You also have to ask if the $ spent on these solar panels might be better spent on your house, where they will never be in an indoor garage, and maybe cheaper/simpler to install.
Not everyone has a garage, or can practically run a line out to the street. A self-charging car would be a good option for many. The charge this can manage is more than I drive, i’d Be very interested.
It manages more than you can drive in ideal conditions. Sunny day, parked in the sun during the day, for probably a ton of extra cost (they are using very fancy solar cells). That might work for people who have a backup plan in arizona with unshaded parking spots available. Hopefully charging stations at apartments and city centers will continue to proliferate to make electric cars viable for more people.
My normal driving is 100 miles a month, mainly on weekends. Plus, I assume they’ll improve capacity over time. Even if it meant having to go to a public charger once in a while, it would still be a convenience.
If they can bring the cost down on that, for other types of panel manufacturing for non automotive markets, that would be pretty amazing. 22% monocrystalline silicon 156mm cells are a commodity now (such as to build a 60 or 72 cells panel with and sell it under $0.60/watt), but 30 to 34% GaAs cells are incredibly expensive.
Until very recently GaAs triple junction cells have been so costly they are only used on satellites and other spacecraft.
If they can make them as cheap as silicon then obviously people will buy them instead, but it's not clear to me that panel efficiency is a relevant factor in the economics of commercial solar power.
Interestingly it is, but more because of the associated costs. Extra panel efficiency means you need less land, less mounting hardware, and fewer installers for the same power solar farm.
