If solar tech gets more efficient or cheaper, I think it starts becoming a much more attractive option in some areas. If you get into the 10+ miles per day range, that would cover a lot of peoples commutes in certain areas.
ETA: and the fact that this option is tied to the significantly less efficient 19" wheel package, instead of the standard 17" wheels, means that this will never, ever be a net benefit.
If this quoted number comes from the manufacturer itself, then I think the answer is "no".
If you’re suggesting it wouldn’t work in a garage, that’s obviously true (and another factor in whether car solar makes sense) but many (most?) people park their cars outside during the day anyway. I for one can’t remember the last time I parked under cover
Most cars are already sitting in the sun all day.
In the old days, they used duty cycle to adapt to the changing load. Modern ones do things like varying compressor displacement or compressor speed to adapt to the load. Variable frequency inverters are used to efficiently drive electric compressors.
The variable displacement trick is used in ones mechanically linked to internal combustion engines. It can vary the compression stroke to account for different load as well as different engine speed.
At the low end maybe achievable with a full rooftop covered in solar panels, but probably not adequate at 1kW+.
Manufacturing cost is like $40 cells, $20 electronics and $200 in glass fusion, mounting, etc.
My car eats 200W just being online so it would be useless to charge from solar.
2.86 miles of charge, but only if left outside, uncovered, in full sun, on a fully sunny day, for a full 8 hours, in a place that gets effectively the maximum amount of solar radiation per day out of anywhere in the entire country.
Now, do the same experiment anywhere else in the country, that doesn't get max solar radiation, or that can't get full sunlight for full 8 hours, or where it's cloudy at all, or rainy at all.
2.86 miles per day is the practical MAXIMUM, given perfect conditions. For the average scenario it'd be some fraction of that.
The 6 miles figure is what they said you'd get if, in addition to perfect conditions, "if the sun shifted its orbit" (?) and gave perfect sunlight for 12 hours straight. Which is a number which should obviously not be thrown around as if it's obtainable.
The fact that they're quoting numbers about what range you'd get if the solar system was constructed differently also makes me doubt the impartiality of their experiment and the numbers they provided.
[0] https://www.motortrend.com/features/the-2023-toyota-prius-pr...
https://www.epa.gov/greenvehicles/fuel-economy-and-ev-range-...
EV EPA range historically has been overstated. However, the water is muddied because the EPA doesn't really force the manufacturers to give an accurate number. A manufacturer can choose a highway only test, but then also arbitrarily decide to derate the value (EPA example is 70%). A manufacturer can choose to include city driving in the rating and weigh it accordingly and also derate the value (if they want).
Tesla traditionally (still the vast majority of new and used EV market share) has been the only manufacturer that uses the highway + city driving tests. People then get surprised when the car cannot do the full range at 85 MPH.
All in all, this is the EPAs fault. For EVs they really need two numbers, city driving range and highway driving range. EVs are so much more efficient than ICE that speed makes a huge difference given there substantially smaller energy density.
https://www.epa.gov/greenvehicles/fuel-economy-and-ev-range-...
Neither is the voltage when you plug it in at home. The car has a unit specifically to convert the voltage.
If you're saying they didn't connect the right wires for that, that sucks but is easily fixed.
> it's all out the window the second the car starts the ICE side of the hybrid drive system for even an instant
Nah, doing a drive where it's 99% solar power and 1% "burned an ounce of gas to maintain the engine for the month" is fine.
In your particular setup.
A typical car can expose about 3 square meters of lateral area for those same 8 hours, and receive 3 kW of irradiance. multijunction cells can exceed 50% efficiency, so we're talking about a theoretical upper limit of 12 kWh electric per day.
That would require a vehicle totally covered in cells, including the windows, so not very practical, but adding up to 30 miles/50 km per day is nothing to sneeze at.
We could also imagine all sorts of solar receivers that engage during parking and inflate the apparent surface within the limits available, track the sun etc. to maximize energy.
> multijunction cells can exceed 50% efficiency
The maximum demonstrated efficiency of a multijunction cell, in a lab, WITH CONCENTRATION is less than 50%. Commercially available cells are lower.
Concentration is an important caveat for two reasons:
First, it implies that you are collecting light from a larger area than the PV panel itself. Second, efficiency grows with increased irradiance (so efficiency will be lower without concentration).
> 3 square meters of lateral area
Lateral area is meaningless. It’s all about area perpendicular to the solar axis. Unless you are driving a box van or a big pickup truck, there is zero probability that you can put 3 kW of irradiance on your panels. Neither of those vehicles will achieve kWh/mile numbers anywhere close to a Prius.
In practice, you need to halve the efficiency and more than halve the collection area you quoted. You also need to account for conversion losses.
The multijunction theoretical efficiency limit is 87% with infinite junctions, and over 50% with a practical number of junctions. There's nothing stopping you from creating a miniatural concentrating solar device that focuses the light from a 10 cm^2 area onto a 0.5cm^2 cell, we haven't seen such devices because the cost and extra mass exceed what you get from the efficiency gains when you can simply increase area; a very area constrained application with high power requirements might change that.
> It’s all about area perpendicular to the solar axis. Unless you are driving a box van or a big pickup truck
Again, what stops the top hood and engine cover of a Prius from raising at an angle and tracking the sun, perhaps even unfurl additional area? what about the area of the doors and windows?
Current solar cars can drive 1000 km per day with an average speed approaching 100km/h. It doesn't seem completely out of the realm of the possible to achieve 50km in an hour for a passenger car that can expose similar area while parked.
You replied to (and even quoted) a comment explaining the practical limits, then doubled-down and said multi junction cells can exceed a number which has never been experimentally demonstrated.
And here you are again saying that multifunction cells can achieve 87% efficiency.
An ICE engine can achieve 100% thermal efficiency with the right Th and Tc. That has about as much relevance to the discussion at hand as 87% efficient solar panels.
Let me be clear: the most efficient cells that have ever been experimentally demonstrated under any conditions are less efficient than the number you originally stated. In real world conditions the number is half of what you originally.
> Again, what stops the top hood and engine cover of a Prius from raising at an angle and tracking the
I guess I’m just feeding the trolls here.
I believe having a carport and house roof covered with solar panels + (PH)EV is the best option.
But looking at some proper pictures, it covers most of the midroof with 7x8 tiles of solar. But you could fit a good percentage, even sticking with a design where a huge amount of the roof into the trunk is all glass. And there are no panels on the hood. So that's an easy doubling right there, more with an average car roof shape.
>13.6 kWh battery. 39mile EPA range... 915 Wh... 2.86 miles, not 3-6
I'm hooking it up via starlink specifically so it works in remote areas with no cell coverage too.
Monitoring and proxying everything via an RPI as well. Victron DC-DC inverter to keep the bluetti battery pack charged with bluetooth relay boards so we can turn loads (camera/starlink/others) on/off programmatically (it only turns the starlink on when there's no good/known wifi for example).
Fun project, combines software dev (which I'm fairly good at) with hardware work (which I'm less) and my dogs (which I'm a big fan of).
But!
That's a practical consideration at the level of "should a government require EV makers to design the roof, bonnet, doors etc. to be tiled in PV in order to reduce, but not eliminate, the induced extra demand on the grid" and definitely not "should I personally bolt a small, fixed, PV panel and inverter into my EV as an aftermarket DIY job?"
The former gets wind-tunnel tests for efficiency, QA, designed around all the other safety concerns cars have e.g. crash safety.
The latter, doesn't.