Solar will hardly be efficient enough, unless you'd have a whole solar farm beside each station...

Also add maintenance of all those batteries and I bet you'd have a really hard time to motivate solar for economical reasons.

I doubt those stations will store the power locally. My bet is that the solar system pumps power into the grid during the day, generating $$ for tesla. Then in the night, it draws from the grid since power is cheaper then anyway.

The way solar works in california for small installations is you just produce it and use it and whatever you do not use just send it to the electric company. If you need power you are not producing then you just take it from the electric grid. The electric company has to take your excess power (by law). The electric company then subtracts the power you put in from the power you use and only charges you for the difference.

So currently you do not have to worry about batteries or storage. You only have to worry about producing on average about as much as you use. The electric company does not have to worry about storage either because times of high sunshine always coincide with times of high electricity demand (due to air-conditioning).

So currently one can easily install and use solar without ever worrying about batteries or storage. If we ever get to the point where we rely exclusively on solar and wind, we will have to start worrying about storage, but this point is far off for now. Also, at that point the responsibility for storage will likely fall on the electric companies.

According to the article it sounds like the devices are hooked up to the grid, but use solar effectively to offset the cost - Musk claim they will feed more energy into the grid than they'll take out while charging cars.

The solar component is a stunt. Electricity is fungible. How about putting the solar plants where they work well (mountaintop? desert?) and the charging stations can just hook to the grid. Then they can get their electricity from any convenient source (local nuke plant for instance).

The argument about 'free solar' is almost an oxymoron. That electricity costs more per kwh than most any other source.

It is not a stunt. It is a direct counter to the anti-EV argument "Electricity is made from fossil fuels anyway, so by driving an EV you are just shifting the source of pollution to the power plant."

Tesla is attacking every single anti-EV argument in a very deliberate way and most of the attacks are strong successes.

It IS a stunt, in the sense that the solar feature is technically independent of the charging stations. The message is clear, but there is no necessary link between the solar elements and the place you go with your electric car to charge up. Placing them there is probably a worse decision that placing them optimally. That's makes it stunt.

And there is also a strong argument that the manufacturing and installation costs of solar farms has a long payback. They are a battery in that sense - energy invested in them slowly comes back out. PRobably petro-energy. So intially solar is a net negative in eco-impact. Same with wind.

At $2/W, filling up a roadster would require $106,000 in solar panels. More if you anticipate more than one fill up per hour.

Probably much cheaper than installing tanks in the ground and pumps on the surface to handle gasoline. Not to mention remediating the site when the tanks eventually start to fail.

There's an old service station near me. It was once a fuel station, but was eventually turned into just-a-repair-garage. Transmissions, mainly. But they didn't remove the tanks when the locale switched gears. That garage is now defunct; there are potential entrepreneurs who want to use the space, but the cost of removing the old tanks and cleaning up the site for alternate zoning (one of the people looking at it was thinking about opening a cafe) is going to be prohibitively expensive.

Tack on to that the increased capacity electric vehicles are going to have to have, as well as the increased electricity prices I am expecting when ten million Americans are charging their cars.

Current U.S. energy use is ~ 10 billion kw-h per day.

1 billion kw-h / day more is a nice big tick on that, but I'm not sure it would drive prices a whole lot.

Yah, but those people won't be using refined gasoline. It uses alot of electricity just to refine a gallon of gas.

According to this web page:

http://www.consumerenergyreport.com/2012/03/21/what-makes-up...

It takes about $0.20 to refine a gallon of gas, so ~2kWh/gal. Except, It obviously actually takes less electricity than that, because there are other costs to refining. Not a bad investment in energy terms, when a gallon of gasoline contains ~36.6kWh worth of energy.

Where on that page did you get the 20 cents? Didn't see that anywhere. From this http://gatewayev.org/how-much-electricity-is-used-refine-a-g... It's more like 6kWh/gallon.

Don't forget the cost in electricity of finding deposits, mining them, transporting the pre-refined gas, transporting the post-refined gas, and lobbying Congress.

I just imagined the Congressional Cattle Prod, wrapped in $100 bills.

Surely increased demand for a resource should, long-term, drive the price down and not up?

Potentially, if there are improvements in infrastructure to be made that reduce cost. But it is hardly implicit that increased demand will lower the price- just look at oil.

The stations generate more power (via solar) than the cars use while charging. There is a net REDUCTION in energy use if you charge solely from these stations and I'd imagine that part of the business model is selling the excess energy back to the power companies. I'd bet that getting certified for this sort of thing is also a heck of a lot easier than getting certified to build a solar farm. Pretty smart move I think.