Does Tesla's Supercharger answer the road trip question for EVs?

9/26/2012 11:42 PM EDT

Personally, I wouldn't mind waiting 20 extra minutes to make my road trip free, but your 20 more minutes might be more valuable than mine.

9/27/2012 1:57 AM EDT

@jhall118- good point. Let's not forget, Tesla is promising free charging. That has to at least partially make up for the longer stop.

10/4/2012 3:49 PM EDT

This 100kW supercharger is a step in the right directions, but not nearly far enough. When they get to 1 Megawatt, it will get a lot more compelling for full gasoline-powered vehicle replacement by EVs.

I'm still hoping for Doc Brown's "Mr Fusion" home reactor mounted on the back of the car :)

9/26/2012 4:09 PM EDT

@Bert- fair points, especially about the long lines that would form for 30-minute charges if EVs were really popular. But about the grid, Tesla says the solar-powered Superchargers actually give more back to the grid than it will take to charge the cars.

9/26/2012 4:21 PM EDT

Heh. They might claim that, but does that claim cover the case case where the stations are operating around the clock?

Think of it this way. If each car had solar panels on their roof, would that provide enough energy for driving the car? I mean, assuming more than just a tiny little experimental vehicle?

Now exacerbate that problem by a 30-minute "refueling," where the energy required for each car driving 3 hours or so is crammed into 30 minutes. And by the fact that you're doing this for potentially many cars simultaneously.

I'm sure one can do the numbers, to determine just how much solar panel area would be required. All I can say is, roof panels on EVs don't come close to generating enough power. So multply that car-roof area by at least 6 * the number of cars fueling at a time * a factor to account for the fact that this calculation only works for 12:00 noon on a sunny day * a factor to accoun t for the fact that the roof area isn't enough for practical cars, and that should give an idea whether you can net give the grid any power.

9/26/2012 11:39 PM EDT

Your thought experiment is pretty meaningless... the charging station is not limited to the area of the roof on the car.

However, your conclusion is probably right. If the station was being run 24/7 it wouldn't work. Good thing Tesla knows how many cars they are selling in each area and can plan accordingly.

9/27/2012 4:34 AM EDT

Obviously, the roof of the car was intended to give an idea of the area required for solar panels. As opposed to just armwaving about how these charging stations were going to be able to give you free energy.

9/26/2012 11:32 PM EDT

According to a Tesla chief engineer after the unveiling, the damage to the battery is no different than any other form of charging. It's designed to bypass the charging hardware and do some other stuff that a biologist like me doesn't really understand. Keep in mind that the 85kwh batteries have an 8 year warranty.

As for Hydrogen and other fuel cell technologies... you have an even greater infrastructure problem and/or at least with hydrogen it's even worse, because you are literally using MORE electricity to make hydrogen than it would take just to run the car with electricity to begin with.

9/27/2012 4:31 AM EDT

Infrastructure problem? We can't deliver gasoline, diesel, or bioduels to standard gasoline stations?

You put a hydrocarbon fuel in a tank in the car. And then you extract the H2 on board, and feed the H2 to the fuel cells. You may need a small battery, similar to that of a mild hybrid, for short power bursts.

No energy shortfall, no infrastructure change, no heavy and low specific energy battery to contend with, no problem with friving range.

Look it up. It's doable, and I think it has a lot more potential than battery-powered electrics.

9/26/2012 11:41 PM EDT

You are thinking an electric car is like building a new gas car. 95% of my charging will be done at home in my garage. A large number of people commute less than 300 miles a day. Superchargers aren't the gas stations of electric cars, they are just for taking long trips.

As electric cars become more popular, obviously more stations will be built. You could make the same argument against gasoline cars when the first stations were going up.

9/27/2012 4:38 AM EDT

Remember that battery powered electric cars also existed at the dawn of the automobile age. And they didn't survive then, for the same reasons as they are having a tough time now.

9/28/2012 4:22 AM EDT

You beat me to it, Fabio. This is surely the way to go. If this existed already, imagine the scorn if you suggested having to spend 5 minutes pumping a high flamable, smelly liquid into your car instead of letting a robot change your battery in 1 minute.

10/4/2012 3:47 PM EDT

Sounds great, but there is a cost associated with replacing used batteries with fully-charged brand new ones. Who will pay that cost, and what do you do with the used ones? Recharge them and offer them at the supercharger station? Sure, I'll let you have my 6 month old batteries in exchange for those fully charged 2 year old batteries because I'm in a hurry and don't want to wait to charge mine.

There are safety issues and labor cost issues as well with this idea. Swapping out a bank of Li-ion batteries in an EV is not nearly as simple as replacing the lead acid battery in a gasoline-powered car. Will each charging station have a staff of well-trained auto mechanics? Who pays for them?

10/9/2012 4:07 AM EDT

Hi Frank, yes, "who owns the battery" is always the question. But the answer could be: "not the EV user". For schemes where the battery hardware is swapped out (like the scheme proposed by companies like Better Place), the EV user does NOT pay for (and therefore does not own) the battery - the user is not buying a piece of hardware or a fuel; the user is buying a service: a charged battery, which is really "distance travelled".

Of course, if you have already paid for your EV battery, then you would probably not want to participate in this type of scheme (depending on the condition of your battery!)

But for wet-chemistry batteries, the EV user owning the "battery" is just fine: the battery hardware stays in the EV, only the liquid electrolyte is exchanged; in the case the commodity being purchased is replacement electrolyte, which is more like what we do now with fossil fuels.

As for the practicalities of swapping battery hardware (labour costs, safety issues, etc): as the video shows, a battery changing robot will do this in just a couple of minutes. Of course, this means that batteries need to be built to certain form-factors and standards. But here we are at the cusp of this new industry, if standards are implemented now then this type of idea can become widely adopted. And with that will come the significant benefits of having substantial energy storage connected to the grid.