It's the Batteries, Stupid!

[JRP3]

Except in your charging scheme you mostly eliminate the daily full power operation for mostly low power operation with intermittent power ups for charging, unless the charge station is consistently very busy every day.

[jerry33]

I don't think fast charging will have daily usage by anyone. I think that a small percentage of travelers will be utilizing fast charging. It may be possible to supplement our infrastructure with batteries that can store some power for this infrequent high draw.

I'd think every traveler would use fast charging if there was any available. Even with fast charging, it's still 45-60 minutes. Or did you mean that just a small percentage of vehicles at any given time are travelers?

[NuclearPowered]

But that is the way most gas turbine powerplants run. They run hard during the very few peak hours of the day and are completely off overnight.
Robert.Boston, you reading this thread?

I don't believe this is by choice.

[Robert.Boston]

But that is the way most gas turbine powerplants run. They run hard during the very few peak hours of the day and are completely off overnight.

Gas turbines run as you describe, richkae. There are several practical problems with your otherwise attractive idea:

• The gold-standard for natural gas generation is the combined-cycle unit, not a simple gas turbine. The CC is about 30% more efficient than a gas turbine, so you're not going to make up the gap through reduced losses.
• This size generator may need to go through an interconnection review process, which isn't fast, easy, or cheap.
• This size generator may require air permits, the process for which is also not fast, easy, or cheap.
• This size generator may require zoning variances; not fast, easy, or cheap.

I think @DuncanWatson has the truth of it, though: these SuperDuperChargers will be located to support inter-city travel and will require dedicated sub-transmission infrastructure. Utilities don't have a lot of experience with instant-on 2MW loads!

[Robert.Boston]

I don't believe this is by choice.

Nah, these simple turbines are designed and built to be cycled, not base loaded. If you're going to be using a plant at a capacity factor north of ~20%, you spend more capital to buy greater efficiency in a combined-cycle plant.

[dpeilow]

We have an example where there is just one location on the A1 needed for complete London to Edinburgh CHAdeMO coverage. Everyone's known this for a year or more, yet even with the millions available in the region it's needed and willingness of a host site at the nescessary location, they still can't get it installed because of the need to upgrade the local 11kV feeder.

It actually sounds like the idea use for one of those battery-backed CHAdeMO chargers.

[Todd Burch]

If battery energy density improves at 7% per year, we'll have 1000mi batteries on a Model S-like vehicle by around 2030.

However, I tend to believe that a range like that will come sooner than 2030...a disruptive new battery technology (carbon nanotubes?) will appear by that time and instantly perhaps double or triple battery energy density.

Assuming that's the case, let's say that by 2025 we have 1200-1500 mi range batteries. Doesn't that make all of this charging discussion moot? By that time, range will be getting close to the point where people really won't have to recharge at all during their trip. Or, perhaps if they're doing a long cross-country (3000 mi) drive, they might need to stop for a day to recharge.

Based on early successes of some battery technologies, this type of range could be here within 15 years. Is anyone really going to invest in a massive, expensive high output recharging infrastructure that will be useful for perhaps just a decade, perhaps 3 decades at most?

[jerry33]

Assuming that's the case, let's say that by 2025 we have 1200-1500 mi range batteries. Doesn't that make all of this charging discussion moot? By that time, range will be getting close to the point where people really won't have to recharge at all during their trip. Or, perhaps if they're doing a long cross-country (3000 mi) drive, they might need to stop for a day to recharge.

Maybe, but that will be too late to do me any good Also future predictions of technology have always been off the mark. For example, we should have had almost all of our electricity nuclear powered by now, instead of just a tiny fraction. Bubble memory didn't work out so well either. Even near term predictions don't work out well. Take the EVGo charging network in DFW. At the time of the Leaf dog an pony show in spring 2011 they said that there would be 30 to 40 charging stations by September. It's May of 2012 and there are three, one of which is at the airport. Putting dots on a map is easy. Getting a test result in a lab is harder but comparatively easy to building a viable commercial product.

Generally, you go with what you have at the time and then convert. My opinion is that if there isn't a good infrastructure then BEVs won't succeed and bringing the more advanced batteries to market will never happen.

[JRP3]

Not only would density need to improve dramatically costs would also have to drop dramatically to make it practical to put 1000+ miles of range into a vehicle, something that no one actually needs, so I doubt it will ever happen.

[jerry33]

Not only would density need to improve dramatically costs would also have to drop dramatically to make it practical to put 1000+ miles of range into a vehicle, something that no one actually needs, so I doubt it will ever happen.

I don't think that's the way to look at it. Consider truck tires (the 18-wheeler variety). To build a tire that will carry the weight you automatically put 500,000 miles or so of life in the carcass. Now it would be more economical to have a truck tire that would have it's tread worn out at the end of the casing life. However, a 500,000 mile tread life is not within the scope of current technology (in the best case you get about 350,000 miles for truck tire tread life but most highway trucks get 150,000 to 200,000 miles) and to reduce the casing life means that you won't be able to carry the required load. This means that to get the full casing life you retread the tires, which adds expense and inconvenience (but is still cheaper than a new tire).

So let's say, a 24kW battery gives 8 years of service and 60 miles, an 85kW battery gives 12 years of service and 250 miles, and a 300kW battery gives 20 years of service and 1000 miles. You get the 300kW battery because you'll never have to replace it--not because it goes 1000 miles.