Plugged-In Vision - Part 2
By Bill Moore
The plug-in, grid-connected, charge-depletion electric-hybrid has a lot of good things going for as Dr. Frank enumerated in Part One of our interview. Better performance, lower-operating costs, fueled by American electrical energy, dramatically cleaner emissions, batteries with 150,000 lifecycles and all for the cost of adding leather seats and a sun roof to a conventional SUV.
On top of this, you'd have an SUV you could run your home off of in case of a power outage and, assuming your utility offered it, the ability to actually put power back into the grid -- a strategy called Vehicle-To-Grid charging -- that would put money in your pocket.
So, with all that the concept has going for it, why all the talk about hydrogen and fuel cells, I asked him?
Dr. Frank responds that while he sees a number of issues with hydrogen, he doesn't see it as an alternative, necessarily to his plug-in hybrid concept. He says that hydrogen could simply be used to replace gasoline in the ICE or even fuel cell vehicle. The grid-charged hybrid makes sense regardless of the energy source.
Taking Frank's architecture to its logical conclusion, going the charge-depletion hybrid route in a fuel cell vehicle would enable designers to downsize the fuel cell stack. This means you could lower the cost of the vehicle because more energy would be coming from the battery pack -- whose cost per kilowatt is substantially less than a fuel cell. This would let carmakers offer them sooner rather than later, again depending on the availability of hydrogen.
"We have looked at this plug-in hybrid technology as a road to advanced technology. and that advanced technology can include fuel cells, as well," he tells EV World.
Improving ICE Efficiency
Another engineering payoff of plug-in hybrids are dramatic improvements in engine thermal efficiency. Dr. Frank calculates that this approach can raise the overall efficiency of the vehicle's internal combustion engine/hybrid system to 40% which is even higher than the current best fuel cell technology.
"We are now looking at gasoline engine thermal efficiencies over 40%, which is now approaching the best of hydrogen fuel cell technology"
That sounds like a mighty tall claim, but Franks contends that this approach enables him to not only downsize the IC engine, but to strip it of many of its power-robbing accessories starting with the fan belt-driven water pump, the radiator, alternator, and starter motor.
An electrical water pump helps cool the engine using an internal thermistor and a closed cooling loop. These are electronically controlled by computer.
"We can now pump only the water we need to cool the engine," he says. "There is a huge energy savings in the water pump alone."
Dr. Frank points out that with shaft power efficiencies of over 40%, UC Davis' gasoline engines are approaching the efficiency of diesel engines, but without the cost or pollution control problems associated with these compression ignition engines. He also adds that the incremental cost of his plug-in hybrid IC is comparable to the cost of the traditionally more expensive diesel engine.
For Frank, the fundamental problems with hydrogen include lack of availability, storage and range or what might also be called energy density. At present hydrogen is not readily available to the average consumer. Secondly, storing it safely and in sufficient quantities for meaningful travel range is also a problem. He points out that most of the current prototype hydrogen vehicles have ranges of between 70-80 miles in real world driving situations.
He contends that by the time you would find a hydrogen refueling station, you'd have used up a significant percentage of your fuel just getting to and from the station.
"It's a long ways before the hydrogen infrastructure is constructed," he notes. "That's the first thing."
His next concern is the cost of fuel cells, which he contends are as much as 10 times more than the cost of a comparable gasoline engine. "It'll be a long time before that cost comes down."
Part of the reason is the cost of platinum, one of the key materials used in a PEM-type fuel cell stack. One estimate EV World came across recently is that more than 40% of the cost of a fuel cell is the platinum, a precious material more costly than gold on an once-by-once basis.
(Platinum is currently trading in the $690 an ounce range while gold is in the $350 per troy ounce range.)
Frank says that since there is no current substitute for platinum on the near horizon, getting over this cost barrier will be a challenge.
Finally there is the issue of energy efficiency. He tells EV World that the process of charging a battery is about 80% efficient in terms of energy in and energy out. By contrast, the most efficient way to make hydrogen from steam-reformed natural gas is about 40% efficient. Then you have to take in the losses accounted in storage and the fuel cell itself. Hydrogen electrolysis is even less efficient.
Dr Frank argues that by the time you look at all of the inefficiencies in our current hydrogen fuel cell system, which is admittedly in its early stages of development, the overall well-to-wheel efficiency of a fuel cell vehicle drops below that of an internal combustion engine.
When asked under what scenarios does hydrogen make sense, he chuckles and replies, "If you living on the sun, I guess." He is, however, confident that mankind's creativity and ingenuity will eventually overcome the issues of using hydrogen more widely as an energy carrier. He says we're not yet done inventing.
He is also not completely convinced that hydrogen is the answer either, arguing that he's seen many promising technologies come and go over the last 50 years, many promising to revolutionize the world only to be superseded by something better, cheaper or more efficient. Hydrogen might be the "fuel" of the future or it might be replaced by something not yet discovered.
"Perhaps it will end up hydrogen. Perhaps it will end up 'unobtainium."
Role of Nuclear Power?
It has been suggested that the only energy source that generates no CO2 and can be depended upon to produce electric power either for plug-in hybrids or to make hydrogen is nuclear power. Frank agrees that grid-connected hybrids will require more electric energy than the current grid can provide once they reach a concentration of about 20% of the current vehicle fleet. Prior to that, from studies he has done for the state of California, the cars can utilize unused off-peak capacity.
So, he admits that we may have to go down the nuclear pathway at some point in the future, but he estimates it would take 10 years at least to reach that point. But from his perspective, he has few issues with nuclear power, especially the problem of waste. He believes that eventually a benign use will even be found the various radioactive wastes that result from the nuclear fuels proceess.
[Editor's note: One not-so-benign use for the waste that results from the enrichment of nuclear fuel rods is depleted uranium - DU - warheads which were used extensively in Gulf War One and in Kosovo and may again be used if the US invades Iraq, which may happen sometime on or after March 17, 2003].
"What we consider nuclear waste today, could be an energy source tomorrow," he says.
Electricity, the Power of the Future
Dr. Frank is confident that the electricity is the best power source for the future, be it powering vehicles or home appliances. But he also thinks it needs to be used directly, no converted into some other form of energy like hydrogen and then back to electricity. He points out that every time you change from one form to another, you lose efficiency.
He adds that he's "not knocking" research into hydrogen, but that we already know how to very efficiently put power into and take it out of batteries at a rate of about 80% efficiency. By contrast hydrogen electrolysis is only aboefficienticienct. In effect we are throwing away more than half of the electricity to make hydrogen.
Finally, EV World asked Dr. Frank about what it will take to get car companies to take a serious look at the plug-in hybrid concept. He said that it takes demand from the public. If the public demands it, car companies will find a way to build it affordably, though he also acknowledges the fact that Detroit's huge advertising budgets also influence what the public wants.
So, one way around this obstacle is by regulation, something carmakers loathe and fight against, but which can help stimulate public demand. He says he is encouraged by the fact that for the first time, California's Air Resources Board, has included plug-in hybrids in its revised ZEV mandate. He thinks that will encourage automakes to begin to look at this option, but he added that he also thinks that the Japanese will have a plug-in hybrid available long before Detroit.
Now, that would make for a very interesting development.
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