The 30 percent figure is for the carnot cycle, and not to the wheels, in truth.
With the current state of the art, fuel cells lose efficiency when they are required to produce a lot of power. That's where you see those sub 50 percent numbers. Which is why, to keep efficiency high, you use an auxiliary battery, like hybrids do.
For instance, an efficiently designed car (which leaves out SUV pigs) requires only about 12 HP to run at a steady 50 mph. And some more at higher speeds. The high transient demands can be met with the aux battery rather than the fuel cell.
Longevity is another issue, but that too is being addressed. Initially, they may need to be easily replaceable.
Work is being done on all of these fronts, for fuel cells. Batteries have infinitely worse liabilities, and everyone seems to just assume that's the only way to go. It's not. There's no future there, not for a long time. And, as many have said, the electricity to charge those batteries won't come out of thin air.
According to wikipedia, fuel cells are only 40-60% efficient. I'm picking that in real-world conditions (ie. dirty fuel, too cold/hot, after 5000 miles of use), the efficiency will be around 40%.
I doubt very much that the whole process of delivering power to the wheels is going to be 60% efficient for fuel cells.
Burning fuel in an ICE delivers approx 30% to the wheels.
In an electric system, the motor is approx 90% efficient and the ECU is approx 90% efficient. That means the fuel cell itself needs to be approx 75% efficient to his 60%. That is quite a demanding target to reach and maintain.
Do fuel cells operate efficiently after 10,000 miles and in real world conditions?
Then apply the efficiency of the motor control + motor and you're down to 30% or so.
Even if the battery technology fairy comes wave his wand, where is all the electricity going to come from?
We can support a very small % of EVs hanging off the grid, but electrical generation capacity would need to double (more or less) to cope with 50% of vehicles being EVs.
Renewables don't cut it. People will not be prepared to wait for the wind to blow or the sun to shine to recharge their vehicles.
Getting new planning permission for just one generation plant is extremely difficult; doubling up is even harder. Then too, the grid and reticulation needs to be doubled to get the juice to the houses.
At this stage, all these predictions are just nonsense.
The flaw in your logic is that the charging time will be nearly infinite if millions of EVs have replaced gasoline & diesel-powered vehicles and the electric power generation infrastructure isn't there to charge them.
How many new power plants can be built in the next 15 years? Where will the money come from -- higher utility rates now to pay for future capacity? What fuel will those plants use? What percentage will burn coal? Natural gas? Oil? What percentage will use nuclear fission?
Dozens of these large-scale construction projects will need to start almost immediately if we expect to have the electrical energy in 15 years to charge more than half the vehicles in the U.S.
Meanwhile, they can't even get the San Onofre nuclear plant back online. The 1.5 million homes it provided power to are now drawing from other sources in the grid, and the media continues to advise southern Californians to set the thermostat higher and conserve electricity wherever possible to avoid rolling blackouts.
But go ahead and keep dreaming that in 15 years, more than half the cars in the nation will be able to simply plug in and charge a multi-kilowatt battery in a couple of hours.
One of the other issues is simply how much change can the buying public take at a time. The other transportation revolution underway is the drive toward autonomous vehicles. While both revolutions are well understood in this audience, in the general public, electrics get a lot more press. My assessment is that robotics are much further along and are creeping into cars without a whole lot of fanfare.
You hear about a fair number of automation components: lane departure prevention, self-parking, intelligent cruise control, but they tend to be looked as as features rather than steps on the way to fully robotic cars.
Electrics are likely not more than a decade or two behind. I say that simply because I'm very skeptical of seeing a revolution in energy density and charge time any time soon. As soon as an electric storage device that closely mimics the capabilities of a gas tank for near the same cost, the transition to electrics will start in earnest.
If you had read further, you would have seen in the very same post:
"Battery electrics may become a little **more** prevalent, but their range limitations and 'refueling' times are just too severe liabilities for general purpose cars."
I doubt there's an engineeer on the planet who doesn't know that battery powered electric cars have been around for at least 100 years, for heaven's sake. But in spite of the hype and outright lies, their advertized range hardly ever stands real-world tests, except perhaps in the most benevolent conditions. Which is why other forms of energy storage, in cars with electric drivetrains, are where more effort should be spent.
Your comment says
"However, all it takes is a design like the Volt, however with a totally electric drive train (no weaseling about a mechanical link between engine and drivetrain in highway driving), and you have a "fully electric" car."
This comment sure makes it seem like you were not aware that there already exist "fully electric" cars?
Not Apple "evangelising". Just tired of grumpy old men complaining about smartphones.
From technology point of view there is no need of significant breakthrough to make the acceptance of electric car more viable. Put aside the 50% number for a minute and look at what is available now from Tesla.
- Model S, 160 miles range = 50 k
- Model S, 230 Miles range = 60k
- Model S, 300 Miles range = 69k
I am more on the frugal and practical side (The economics has to add up for me) I am willing to buy one of the options above for ~30k. Charge time for these is ~ 1 hour per 60 miles with the quick charge option. That is more than enough day time driving distance for me that can be charged over lunch. In my household we have 2 cars, so I can see one of the cars being electric (local driving) and the other gas (long distance)
So Elon has 15 years to increase the price/performance of his car by 50% to win me over. Mass production of the battery pack and the car itself can reduce the cost of the car by that much with no significant technology breakthrough. Only detailed hard engineering bean counting is needed.
You are looking for more range and techno breakthrough?
- Bring down the cost of carbon composites. Make the full chassis out of light weight materials.
- Move to higher voltage range to allow thinner conductors.
- Take the reduced weight and add more batteries/range.
- Add ultra caps for quick charge/discharge
- Add high efficiency solar cells everywhere to improve range and reduce electric cost
- Improve motor/weight efficiency with exotic magnets
How many of these can you improve on in 15 years?
I think the more difficult task was to make a new car company. That being almost there, the rest is following through and worrying about competition. And make no mistake the competition is there, which is good for all electric economy.
The example above can be applied to Nissan, Ford, and Toyota. All they need to do is bring the cost down and their market will explode.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Are the design challenges the same as with embedded systems, but with a little developer- and IT-skills added in? What do engineers need to know? Rick Merritt talks with two experts about the tools and best options for designing IoT devices in 2016. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.