OK, lets look at what is apparently technically feasible for transport in maybe 2025.

No doubt electric motors will have disappeared into the wheels, or at least just inboard of the wheels to minimise unsprung weight, by then.

This Volvo tech apparently may be able to power the car for ~130km, surely far enough to get them onto induction powered electric highways.

A visitor from the distant past, say around 2010, would be amazed by all these cars, not doubt without drivers, whizzing along with no visible power source!

Now maybe none of this will happen, but there do not seem, so far at least, to be any technical reason they they can't.

I am extremely skeptical of this being a solution for the future of e.cars. The concept is not new and has already being proposed for mobile phone, use the shell as a battery to save cost and weight and volume. The problem is that the shell of a car is exposed to shock absorption which is certainly not where you want to store energy, also replacement of these parts in case of light accidents would be tremendously costly. I think that storage of energy and frame have too different functions and that is not a good idea to merge them for obvious practical reasons.

E-Car roof, hood, booth cover and all windows could eventually become combo solar panels and e-storage units. Those special window panes could dim (on the inside layer) automatically to reduce energy consumption and increase solar energy recovery.

With a few added high performance batteries it could drive hours, specially on sunny days. Many people living in very sunny places would (almost) never have to plug it in. It would fully charge in open parking places.

@Nick:
Some battery chemistries resist damage from punctures very well.
Toshiba's lithium titanate for instance had a video released of their driving a nail through it without is causing a fire.

Volvo must be aware of the potential problem, and are presumably reasonably confident that what they are looking at will cope, as it is surely on their testing schedule.

The same thing really applies to Treehugger's comments.
The problems are obvious, and Volvo must feel that they have a reasonable chance of getting around the problem of dual function materials, and perhaps they may add up to more than the sum of the parts.

There are some pretty tall orders in getting a working technology from this though, I would agree, and can only wish Volvo luck in their brave attempt.

The other car makers don't fancy having a go, which perhaps tells us something about the challenges!

@HarveyD

A few hard numbers. I took the length and width of a typical mid-size car and came up with a plan area of 7.2 m2. If you made an allowance for windows, you might have 5 m2 of area available space and this is probably extremely generous. I live just north of 40 deg so I need to multiply this by 0.75 (I believe you live north of 45 deg so you would need to multiply by 0.7) so now I have 3.25 m2. If I use solar cells that are 20% efficient (very good commercial cells and yes, NASA has extremely expensive cells that are more than 2 this times this efficient) and a flux of 1 KW/m2, I am have a peak of 750 watts available (about i hp). Now if I average over 24 hours, I need to multiple by 24 hr and divide by about 6 to take into account that the day night and the average sun angle. (I calculated the difference between the peak rating at the new Honda plant in TN and the yearly expected KW hrs and yes, I got just about a factor of 6 -- can not beat physics). Now you have about 3 KWh which might give you a range of 8 to 12 miles as the Chevy Volt gets about 2.5 mile/KWh and the Chevy Spark EV gets about 3.9 mile/KWh but this is a smaller car with less available area. Anyway, I do not think that we will have practical solar powered cars or at least not with the cars carrying the solar cells.

Solar cells integrated into all exterior skin including windows need not increase the weight of the vehicle.

The same can be said about other parts and/of combo solar cells/storage that Volvo is working on.

Eventually solar energy, up to 7 to 10 kWh in very sunny places, could be captured and stored for the return trip home after work. The energy for the morning trip would be transferred from the home unit or the grid.

From the above, if installed solar PV will cost $1000 USD for the 1kW of installed power, then, at 2000 kWh/kW/yr over 20 years, the cost per kWh will be 2.5 cents. This, in contrast to 10-15 cents/kWh grid electricity cost in the USA. A very good deal, indeed!

In Europe or Japan, the solar output will be only little above 1000 kWh/kW/yr, so, the cost per kWh of solar energy there will be 4.5-5 cents/kWh. However, Japanese and Europeans pay 20-30 cents/kWh for grid electricity, so the 5 cents/kWh is even a better deal!

Now, for PHEV-20, being able to use solar energy charging during the day at work means no need to plug it in at work, thus allowing for range equal to a PHEV-40 like the Volt without having to carry bulky, heavy and expensive battery pack. No need to have to plug it in twice a day, which can be problem if no plug in receptacle is available at work place.

A PHEV will likely last for over 20 years, due to the fact that the ICE is used only < 1/2 of the time, so enough time to recoup the $1,000 cost of the PV panels. An ICE engine is worn out after 120-150k miles, while a PHEV can run for twice or three times that much before the ICE will wear out.

So, you're on to something here, Harvey! Someday, all PHEV's will have integrated solar PV's on the body panels facing upward. It's just making a lot economic sense and more convenient for PHEV due to less plugging in required for a PHEV-20. PHEV-20 will be the most practical PEV for the near future due to having a balance between weight and cost and full utilization of the battery pack before calendar life degradation.

Convert a cheap engine generator to run on natural gas. Use it to charge your ev. Use exhaust heat for hot water. Use hot water for house heating, hot tubs and washing and bathing. This is cogeneration. it is the cheapest way to reduce CO2 release. Cogeneration at companies for auto charging is even easier with microturbines for multiple automobiles and large cooling systems can use the heat and surplus electricity. Energy from a large battery bank can be sold for frequency regulation as in V2G or used for fast charging or UPS systems. Driving slower would be cheaper than solar energy and requires no additional equipment. Vehicles that use CNG or Liquid fuels or both are the cheapest way to reduce CO2 from automobiles. Instead of plugging a prius into the electric outlet to charge, plug it into a natural gas outlet and let the engine charge it. And it is ready heated or cooled to take off for work with simple electronic timing. The same with volt. The gas company can supply 100 kW of gas flow to a house without much thought and perhaps no new connection to mains. ..HG..