"Shai Agassi, the founder and former CEO of Better Place, also touted the importance of the rate of battery innovation during his talk at the Cleantech Investor Summit. He said the energy density of batteries goes up 15 percent every 18 months; the cost per kilowatt hour goes down 15 percent every 18 months; the life cycles of the batteries (how many times it can charge and recharge) goes up 15 percent every 18 months; and the cost per lifecycle-mile does down 50 percent every 18 months. “If you don’t like the margins in this [electric car] business just wait 12 months,” said Agassi."
I had no idea this was true. If so, that's very significant.
It would be amazing. But it smells very wrong. I suspect any improvements in battery economics is coming from better ~engineering~ manufacturing processes which has quickly eaten up low-hanging fruit, not from anything we expect to repeat.
It is true. And the trend has been obvious for longer than most people realize.
Go read chapter 9 of The Innovator's Dilemma, first published in 2000. This chapter is based on an analysis he did of electric cars. Given the rate of battery improvement he thought that a mass market affordable electric car would be viable for the mass market somewhere around 2020.
At current trends, that's not too far off from when Tesla can be expected to try to make a mass market electric car aimed at ordinary people.
I'd say the barrier to mass-market electric cars isn't battery size, the Model S can already go over 300 KMs on a single charge, which is very reasonable. The lack of quick charging infrastructure is much more troubling. Without quick charging, it takes many hours to charge the battery, making long-distance driving infeasible. Quick-chargers also require a rather large supply of power, far more then most homes, or even petrol stations would probably have.
We also have a petrol station on nearly every street corner, but it will take a long while for quick chargers to approach anywhere near this. There is also already a split on adapter standards, which will take time to settle down.
I don't think that will be much of a problem by 2020, either. Musk plans to cover the country with his solar-powered free chargers within 5 years, and he's already said they (now) charge half the battery in 30 minutes. That's not too bad, but by 2020 I think we'll see faster chargers, too. There are already much faster chargers that exist today, but perhaps they aren't that cheap.
Quite a bit on what it takes to control a fuel cell stack in vehicle and stationary applications: www-personal.umich.edu/~annastef/FuelCellPdf/pukrushpan_thesis.pdf
I find it interesting to read that:
o To get the kind of highly variable "transient response" (change in power output) required for automotive applications, the author proposes using a chemical battery as part of the power management system, as the fuel cell system can't itself respond quickly enough.
o The control system is as much or more challenging than that of an internal combustion engine, requiring control of these sub-systems:
__ * Reactant (hydrogen) flow subsystem
__ * Heat and Temperature subsystem
__ * (pure distilled) Water Management subsystem
__ * Power management subsystem
__ * If not fueled by hydrogen, an on-board fuel processor subsystem to break the chosen carbon-based fuel down to hydrogen
With just hydrogen fuel, it still takes an air compressor, three heat exchangers (fuel temp, fuel cell stack heat extraction, compressed air heat extraction), an air humidifier, a water separator, a power converter, a chemical battery (and software of course, to implement the control system) to make it all work in vehicle applications.
If you have enough current and are willing to stuff enough charging hardware into the car, you can do a 60% charge in 5 minutes with today's technology. It's just a matter of waiting for that hardware to go down in price so you can stuff enough into the car to charge the whole battery pack in parallel. Some of that will be helped by investment and R&D. Most of that will happen through economies of scale and the marketplace.
But that said, fuel cells that can utilize natural gas or propane would be fierce competition. That would give you better energy density, greater range, and access to fuel is already widespread. Quick charging would be solved. The only question left is the cost of ownership of the fuel cells.
The Model S has the frunk, couldn't that be used to fit a removable fuel cell/small engine/whatever that can recharge the batteries while driving? So normally you leave the frunk empty, but if you're going on a longer trip, you pop in your extended engine, fill it up before you go, and stop for gas regularly while on your trip?
> The Model S has the frunk, couldn't that be used to fit a removable fuel cell/small engine/whatever that can recharge the batteries while driving?
The frunk would have to be specifically designed as an engine compartment, both because of regulations, and because one wouldn't want fumes to harm the passengers. (Less of an issue with hydrogen fuel cells.)
I think that's a great idea, though. Something like that would greatly increase the utility of something like a Tesla Model S. Range, in particular range in winter driving, would be greatly improved by the power generation and the ability to use waste heat for passenger compartment heating.
Well ... battery improvements will revolutionize everything. From big battery packs for renewables buffers to return to propeller based aircafts, and maybe even a tablet that could last a whole day linpack-ing.
The problem is that we have evolution now while what we need is revolution. We need order of magnitude more density achieved without the use of rare or exotic materials.
There are many more hurdles than price, energy density, and recharge-cycle limit for batteries.
It's fantastic that 3 of the following 10 items are improving by leaps and bounds. But if all 10 of them don't get better together, the Internal combustion engine will still be making the Tesla Model S look like a rich person's toy.
1. How much does it weigh? If it weighs too much, maxing out on all the other attributes doesn't matter.
2. Does it harm anyone if a person is in close proximity when the battery is crushed, shot, or wrecked in any way?
3. Does the lifespan decrease with prolonged usage in -40F or 150F weather? Does vibration break it?
4. How long does it take to fill up assuming unlimited power resources?
5. How long does it take to charge given roadside assistance resources?
6. How many charge-discharge cycles?
7. If you leave the car in a garage for 6 months is the battery bricked? What is the discharge rate when left unattended?
8. Cost of replacing the battery.
9. Toxic chemicals or rare metals to make disposing the battery expensive or bad for landfills?
10. How quickly can you discharge the battery without it melting or exploding?
The success of battery powered cars doesn't have to hinge on any of these items if Gasoline prices were to triple while the cost of batteries stay the same. Then battery powered cars will immediately dominate, and solar power charging stations in your roof will be the only economical choice.
1. Improving dramatically with improvements in energy-density. The weight of a battery-pack capable of >140miles plus electric motor weighs less than the gasoline engine it replaces, not counting the weight of a full tank. (this is based on battery packs available commercially from several years ago - a friend built an electric 911 with Kokam cells with these specs).
2. Conventional Li-Ion (cobalt) cells are definitely dangerous, best stick with NiMH or LiFePO4 to avoid that problem.
3. Those temps are a bit extreme... arguably small markets there.
4. Newer battery tech is reducing the charging time massively... I've read more than a few quotes of ~5 minutes for an 80% charge (diminishing rates beyond that). Example (granted, not near market ready): http://www.extremetech.com/extreme/134635-scientists-develop...
5. That's a much bigger problem... towtrucks would have to have a considerable powerplant on-board for this.
7. Well designed controls should prevent this (shutting down the on-board systems when batteries get below a certain point, rather than taking them past the point of no return).
8. This is coming down fast enough that by the time you have to replace the battery pack, it'll be a non-issue.
9. Again, avoid cobalt-based Li-Ion batteries, and this is not an issue. LiFePO4 batteries are an enormous improvement on this problem - less toxic than the lead cells in your car now.
10. Yet another massive improvement that's a side-effect of the lowered internal resistance in modern batteries. This goes hand-in-hand with the improvements in charge-rates (lower internal resistance means less heat from current, whether going in or coming out of the cells).
> 3. Those temps are a bit extreme... arguably small markets there.
Not really. The high temp is actually on the low side - a parked car in sunlight in the summer can reach 190 degrees!
-40 is a bit extreme for some parts of the world, but in other places it's not unusual. Perhaps not for the entire winter, but certainly as a daily low.
That's the interior of the car, which is effectively a greenhouse.
You don't put the battery packs on the inside of the car any more than you'd put the fuel tank on the inside. Typical placements are underneath the vehicle, arguably the coolest area possible. This is where the Tesla model S places the pack, as does the Fisker Karma, and this is also where the old ('97-'03) RAV4 EV placed the NiMH pack.
It's funny. All the things you mentioned (even disposal!) are essentially a function of pack architecture. Elon Musk has consistently stated that Tesla is a hardcore engineering and technology company, with the R&D subject being... pack architecture. Just look at their patents: http://www.faqs.org/patents/assignee/tesla-motors-inc/
Tesla Motor's solutions to these problems has been:
* Many small cells. Small cells are easier to cool and you get tighter temperature uniformity.
* Active temperature control. Energy is cheap compared to the capital cost of the cells. Active temperature management earns back its own range penalty. It enables the widest choice of cell chemistry.
* Physically isolate the cells to prevent cascading failures.
* Robust battery box rigidizes the vehicle's frame.
* "Skateboard" architecture not unlike GM's Autonomy concept / Hy-Wire prototype (except no fuel cells). You get a low center-of-gravity, battery swap capability, and an aerodynamic belly for free. Pack is easy to access using a standard vehicle lift. Compatible with novel business models, like "buy the car, lease the battery".
* Fine-granularity diagnostics and charge/discharge control. Improves pack reliability, longevity, and performance.
5. How long does it take to charge given roadside assistance resources?
Or will the owner just call AAA for a tow or flat-bed to a charging station?
7. If you leave the car in a garage for 6 months is the battery bricked? What is the discharge rate when left unattended?
Unattended and not plugged in? Else, trickle charge with manual or perhaps robotic plug-in.
9. Toxic chemicals or rare metals to make disposing the battery expensive or bad for landfills?
Lead-acid batteries are generally recycled now, why not newer batteries?
I would expect a battery replacement to be handled as
an exchange, by specialists.
10. How quickly can you discharge the battery without it melting or exploding?
How much acceleration can the tires handle? Crashes were mentioned in item 2.
More about available energy than lifespan, but here's a "tale of woe"
from a test driver in colder weather. I am surprised that the writer
equates the effects of 10F (-12C) weather on battery chemistry
with someone siphoning fuel from the tank, but so it goes.
I have seen hotels in cold climates (Finland) provide electrical
receptacles for block heaters for IC engined vehicles - which might
be adequate for a slow charge, or at least for maintaining a better
working temperature for a battery pack - too bad the writer didn't
have access to something like that.
My takeaway is that colder regions will need denser charging station
networks to serve long-distance travelers, and that all-electric
vehicles will be less popular for long-range multi-charge trips in
colder climates, but still good for daily commutes and any
"out-and-back" trips where the vehicle can be charged at the
destination while the travelers are doing something else.
(meal, meeting, entertainment, overnight stay, whatever).
That really depends on the local climate. Many locations will see temperatures below 0F and above 100F in the same year, and hotter weather can result in much higher temperatures near the road surface than measured by weather stations.
Next time, on a hottest day in the year, put your hand on the roof of your car, after 5 minutes your hand will be cooked like an overdone steak. Combine this with the fact that the driver may be racing to work on the hottest day, while running the AC on full. And 150F is something that happens to the battery every day for a month in many parts of America. And the battery has to handle spike temperatures up to 200F. Racing the car up a hill in the Southern texas sun? The Internal combustion engine can take it no problem because it's made of metal and plastics that can survive 200F. The battery maybe not.
I had no idea this was true. If so, that's very significant.