Electric Car

The Electric Car
Fall 2006

The times, they are a changing. I think we are approaching a change over from the "standard car", with internal combustion engine (ICE) to the electric car. I want to discus that and back up my assertion. Much of what I am going to write here is a repeat, but there is new information and I hope to clarify some things. There is a lot of information, and a lot of misinformation out there, and having time to sort through it, perhaps I can help inform anyone who is interested. A lot is not yet clear. Much remains to shake out.

Generally, a discussion is first, followed by conclusions. I want to present some conclusions, then back up the conclusions with the discusion.

Electric vehicles are the future of transportation.
There will be two distinct varieties, plus a specialized one as follows:
Pure electric - of limited, but important use.
Plug in electric - very important for commuting.
Highway electric - the over the road, full usage.
For plug in beyond commuting, and for highway, electric vehicles will require liquid fuel.
Pure hydrogen distributed as a fuel, is a long way off.

First off, the standard car has been quite successful. So has the ICE and gasoline as a fuel. So why change? They have about reached the end of their development. No further improvement or fixing of problems can be reasonably expected, and there are problems. Here are some.

The ICE burns fuel at high temperature and in a very short interval of time. As a result, nitrogen oxides are formed (high temperature), and combustion is never complete (short interval), so they produce carbon monoxide, which is poisonous, and various unburned hydrocarbons, which cause all manner of air pollution problems. Everyone with any sense knows better than to breathe very much of the exhaust of an ICE. Yet tons of the stuff are spewed out in cities and along highways. "The solution to pollution is dilution" so you can survive as you drive along behind another car, but you are breathing bits of stuff you don't want to, and in cities it can accumulate to dangerous levels.

They are noisy. What goes on inside a cylinder is not an explosion, just a conflagration, but as the exhaust is released, it makes a lot of noise. That can be reduced but not eliminated, with a muffler. There are all manner of gears and other mechanical devices moving and impacting each other, so there is always a background of noise.

Finally, they are mechanically complex, so will always be expensive and somewhat unreliable, and will require a good bit of maintenance. They wear out.

By contrast, an electric motor is simplicity itself. Cheap to produce, and can be recycled by simply replacing the bearings, which are the only wearing parts. Nothing impacts anything, so they are nearly soundless, although there can be a hum. There is a certain amount of controlling equipment, but practically nothing machined. The cost can be quite low, maintenance practically noexistant, and reliability so high that failure need hardly be considered. These traits alone will be enough to cause a switch to electrics as soon as they are available in a practical form, even without their high efficiency (about 75 - 95% compared to about 10-15% for an ICE, 30-35% at best).

About the only thing holding up the electric is the supply of electricity. There is the rub, but it is being overcome in a number of ways.

First the pure electric. These simply have a battery for supply. In addition, they need a motor and control equipment, and will have to have a recharger. Where they can be used, they can't be beat. With the modern batteries becoming available, with better ones on the way, all that is needed is to develop the market, produce and sell them.

The big problem, of course is limited range and long recharge time compared to short usage time. This results from a limited energy storage in even the best batteries, and the power problem. Power is energy divided by time, so you multiply the required power by the ratio of the times. For example, consider an over the road car. A practical present day car cruising at highway speeds needs about 30 kilowatts (40 hp). If you drove it 200 minutes (just over 3 hours), then expected to recharge in 2 minutes (200/2 or 100 times as quickly), you need 100 time the power. That is 3000 kilowatts, or 3 megawatts. That is power station level, something like 1000 amps at 3000 volts, and you are never going to be able to make a safe effective connection that can handle that power, let alone the problem of the filling station needing really heavy electic service to support it. If on the other hand, you ran for a half hour a day and recharged in 10 hours overnight, as for commuting, you only need 1/20 the power, 1.5 kilowatts, and that is easily handled with the home electric service, something like 13 amps at 115 volts.
There is the other problem that you must remain close enough to the recharger to get to it before the battery runs down.

As a result of these two problems, you will never see pure electrics used for over the road travel. On the other hand, there are lots of uses where these problems do not matter. Such things as specialized devices for use in a warehouse or in a supermarket (the scooters for people who can't get around well), lawn mowers, and light vehicles for use in such places as retirement villages or even small towns, where people have only a little way to go, do not need to go fast or carry a lot, and can easily get home if the battery is getting weak, or even have someone give them a lift if they let it run down. The lawn mower is an obvious one, as you use it sporatically and have lots of time to recharge, and it would be nice to get away from all that noise and having to fool with gasoline, and probably eventually having trouble getting it to run.

The next category, plug in, I described in some detail in regard to the GM Volt. These will have a recharger and a rather large battery so they can be ran as a pure electric for commuting, but will have a modest electrical plant on board so they can keep going after the charge is used. The plant only needs to meet the average power requirements. This category will be very important as it removes a lot of transportation energy from the need for fuel, to the grid, thus cutting our fuel needs significantly. It also means the electric plant will not usually operate in a city, thus reducing pollution with plants that produce some.

It might be pointed out that pollution will likely be created at the power plant, but will be much more easily handled there than in cars all over the city. Sometimes, when you can't dilute enough, it is better to concentrate to handle pollution.

The final category, highway, is already nearly here in the form of the GM serial hybrid Volt. The Prius design, being locked into an ICE - motor pair, is a dead end, I think. These present day hybrids will develop further, into the highway electric. They will skip the recharger and their batteries can be quite modest. The batteries need to be modest to handle hybrids, but eventually can be no more than present day car batteries when the electric plants are able to handle the entire power needs, so the battery only needs to get the electric plant up and operating and get the vehicle into motion while that is happening. It would be very desireable to keep moderate batteries to allow regenerative braking. In a city especially, that can mean recovery of significant amounts of energy.

I expect the electric plant to start out as ICE - motor/generator, possibly switch to reformer - fuel cell, and finally, be just a fuel cell. I expect the fuel to be liquid, probably alcohol and perhaps eventually liquid hydrogen (LH2), but LH2 will not be used for quite some time.

As an aside, I find it ironic that most people mistakenly call a cell a battery, and now are calling a battery a cell. The D cell commonly used in a flashlight is mistakenly called a "flashlight battery". It is just a cell. The 2 to 5 of them put into a flashlight form one battery. The so called fuel cell in a car is actually a battery of fuel cells, and more properly could be called a fuel battery. Instead, it looks like it might wind up called a stack.

Hydrogen is something special and makes a lot of things very easy, so it is no wonder a lot of people are interested in it, even enthusiastic about it. Too bad it is so hard to work with.
The thing that makes hydrogen special is it is the only element that is completely ionized by the loss of a single electron. This allows it to readily ionize, with reasonable energy, and what is left is just a proton. Thus the hydriogen ion is very very small; nuclear scale. This allows them to move around easily and engage in all sorts of chemical action. An element such as carbon, requires exotic, high energy physics to become fully ionized, therefore always retains electrons, making it much, much larger than the hydrogen ion; atomic scale. They simply can't get involved in a lot of easy chemical actions available to hydrogen. There is a lot of chemistry involved with hydrogen ions, as a matter of fact, acids involve them and ph, the measure of acidity, is calculated based on the hydrogen ion concentration.

Hydrogen can also be burned as a fuel in an ICE, but that is not too interesting as about the only advantage is no production of carbon compounds such as carbon monoxide, carbon dioxide, and various unburned hydrocarbons you get with gasoline. You lose a lot of the unique advantages of hydrogen.

One of the most interesting properties of hydrogen is the ability of a proton (hydrogen ion) to readily move through certain subtances, such as the proton exchange membrane used in a fuel cell. This is a material much like kitchen plastic wrap, formed into a thin membrane, sandwiched between two electrodes. The electrodes have a shallow grove etched into the face against the membrane, to distribute gas, and there is a bit of a catalyst, usually platinum, at the interface. That is all it takes for a hydrogen fuel cell. Hydrogen gas is fed in on one side and air is passed through on the other. The catalyst causes the hydrogen to leave its electron on the electrode and the proton then passes through the membrane. On the other side, the catalyst makes oxygen take on electrons from the electrode and they then pick up the hydrogen ions (protons) coming through the membrane, thereby forming water. The electrons flow from one electrode to the other through the external circuit, and you have your fuel cell. Hydrogen goes in, air goes through and is slightly depleted in oxygen and enriched in water vapor.

The efficientcy is high (about 90%) and there is no pollution (other than a little waste heat). Hydrogen makes this posible. There is no sound, no vibration, no wear (although the material can degrade over time), and it basically runs on demand, requiring no input other than fuel and air, and no control. This is about as simple and neat as you can ask for, but again, hydrogen makes it possible, which is why hydrogen is so attractive. Yet supplying hydrogen can be a real headache.

The two big problems with hydrogen is it is a gas except at cryogenic temperatures, -453 F, and it is very light, so has low mass density and low energy density. Everyone knows it is light, but just how light? Well, a liter of water is 1000 grams, of gasoline is 737, and of hydrogen, just 70 grams. Put it another way, a gallon of water is 8.3 pounds, of gasoline is 6.1, of hydrogen just 0.5 pounds. This is liquid hydrogen, LH2. It is about 2.5 times as energetic by weight, but by volumn, it takes 4 volumns of LH2 to equal the energy of 1 volumn of gasoline. Your 16 gallon gas tank would have to be replaced by a 48 gallon HEAVILY insulated tank for LH2.

Filling that tank will be a real problem. Right now you can get LH2 here and there in this country, but you better be careful putting it in the tank. OK for technicians fueling a rocket; not the sort of thing a little old lady wants to be doing on her way home from church. It can be done. BMW has an automated filling station where the driver does not even have to get out of the car. A video camera allows a computer to direct the fueling nozzle to the right spot and tend to the fueling.

Even with a well insulated tank, several quarts will evaporate each day. OK for a truck or other equipment kept running so it is using a lot more than it is losing, but not a good idea if you leave your car sitting a few days in the garage. Unless the garage is well ventilated, that could lead to a danger of explosion.

Actually, hydrogen is not as dangerous as it may seem, primarily because it is so light it just rises and is gone. Even if it catches fire, there is almost no radiant energy, so you can stand right beside a hot fire and never feel it. The biggest danger is from freezing and brittleness from the extremely cold LH2. You do not want to get splashed with it. Most materials become so brittle they shatter if struck. LH2 is not the sort of stuff you want to fool with.

There is also danger with the high pressure and likely leaks if you try to use pressurized gaseous hydrogen. The GM Hy-Wire concept car uses 3 bottles pressurized to 5000 psi and they are talking about 10,000. I don't know how far you can go on full bottles, but it is not very far. I do not think pure hydrogen is going to be used by the general public any time soon.

There are ways to concentrate it. It can be absorbed by a suitable metal, forming a hydride. This means extra weight being carried around, and you still have pressure, just not so much for the amount of hydrogen you are carrying. Ordinary borax in solution can absorb a lot of it and easily give it up in the presence of a catalyst. This has the advantage of an unpressurized liquid, but means extra weight and the depleted borax solution would have to be stored in a second tank, then pumped out for recharge when the fuel tank was refilled, but this could be done by ordinary people with ordinary equipment. The filling station would have to have a hydrogen pipe line run to it for recharging the solution and although a few pipe lines exist, it is a big jump to run them all over the place, not to mention, producing the hydrogen in the first place. There is even a means of getting a lot of hydrogen into salt pellets, sort of like the methane hydrates, but using amonia. That would be a solid fuel and I can't see it as a car fuel, not to mention the problem of holding and returning the salt.

In passing, I might mention an advanced ICE that has been announced. It is turbo supercharged, has a high compression ratio (for power and efficiency), and uses alcohol injection to control the knocking, the detonation, that would soon damage or ruin it. It is claimed to be producable for only about $1000 extra, and to be up to 30% more efficient, which would make it competitive with hybrids, which cost about $3000 - $5000 more. Sort of a last gasp of the ICE, but since they will be around for some time as the sole power plant for standard cars, or for the electric plant on serial hybrids, they might make it into production. They are of interest as they could encourage ethanol production.
I don't think the highway electric can be said to have arrived until the electric plant is using some form of a fuel cell. An ICE - motor/generator will be nothing more than a stop gap step on the way. You gain little over just an ICE, only the hybrid ability to run the ICE in a more efficient range. The ICE - motor/generator can be replaced with a hydrogen fuel cell and some means to supply hydrogen. At first, this may be a fuel reformer, simply because they exist and can do the job using present day fuels, such as gasoline, which are readily available. You produce the hydrogen as you use it.
What a reformer does is react the fuel with water at high temperature and probably in the presence of a catalyst. The oxygen from the water combines with the carbon from the fuel, leaving all the hydrogen from the fuel and that from the water, to be used in the fuel cell. Some of the water from the fuel cell is recoverd to supply the water for the reaction to continue. Energy from the oxidation of the carbon provides the high temperature needed. Anyway that is the way it is supposed to work, but just as in the ICE, it is hard to get just the reactions you want and avoid some you don't. These, along with the cabon dioxide expected to be produced, have to be removed from the hydrogen, and that is a problem.
So you have something using fuel like an ICE, and with emmisions much like an ICE, and with about the same overall efficiency as an ICE, so you have not gained very much. However, it is smaller and easier (and cheaper) to manufacture in quantity than an ICE, and is a step in the right direction. It probably will be used for awhile by some manufacturers.
What you want to do is skip the reformer and use fuel from your tank in the fuel cell. This means pure hydrogen, or hydrogen from a hydride or borax solution, or whatever supply sytem builds up. And of course you cannot go to this step until the supply system is there. And why should the system develop until the cars are available? There are advantages to pure hydrogen, and we may one day be distributing and using it, but I don't think so for awhile.
Actually, truck stops could fuel trucks with LH2. They could make good ue of it, and the distribution system could perhaps be built to handle it. I do not see the general public using it. I just cannot see all those parked cars venting fuel all day and all night.
I think a better approach is a fuel cell using a little easier fuel. Liquid fuel. Such a fuel cell exists, the direct methanol fuel cell. It is much like the hydrogen fuel cell, but it uses a solution of methanol in water as the electrolyte instead of the proton exchange membrane. Instead of hydrogen, methanol reacts at the electrode with water. The CO from the methanol combines with the O from the water and leaves as carbon dioxide. The hydrogen from the methanol (4 atoms) and the water (2 atoms) is right there at the electrode where they give up their electrons and pass through the electrolyte much as they do through the membrane, combining with oxygen ions on the other side, just like in the hydrogen cell. It takes a bit of elevated temperature and the proper catalysts, but one using cobalt, nickel, and iron, has been found. Much cheaper than platinum.
Methanol is available and fairly cheap. It is made from the methane in natural gas, so the price would be tied to natural gas, and the carbon dioxide is objectionable, but not very. This would probably be the way to go if the methane hydrates are ever exploited, as that would be a very large supply of methane, just what you need. It could be distributed in the pipe lines and converted here and there, or the methanol could be produced at the well and transported by pipe line to where needed. I have no real idea which would be more efficient.
Trouble is it is poisonous. It is commonly known as wood alcohol. It also has a lower energy density than ethanol. There are also some problems with corrosion.
It turns out there is also a direct ethanol fuel cell under development, which could be even better. It produces 8 electrons per molecule. There is a problem in that there is another carbon in each molecule, and a carbon - carbon bond that causes trouble, else it is much like the methanol fuel cell. It requires a higher temperature, above the boiling point of water, and if things don't work right, aldehydes and acetic acid (vinegar) are formed and you only get 2 electrons per molecule, so it is a bit touchy. Hydrogen makes everything so much easier. I don't even know how you handle a water solution for the electrolyte, with temperature above the boiling point of water, but this is what you run into with other fuels.
The ability to use ethanol, which is already widely available with a well established distribution system, is a big plus. Also, since ethanol can be produced from bio-mass, it is renewable and the carbon dioxide is recycled, so doesn't count. This could make it much more popular.
A word about ethanol from biological sources. Anyone who has paid any attention knows my opinion of corn to ethanol. It really frosts me that instead of leadership and some sense, we get political expediancy. Politicians love it because it looks good and they can ignor the downside. Anyone saying "wait a minute" is just a voice crying in the wilderness. So it means jobs in rural areas where they are needed. So it brings in taxes. So it gets the corn farmers a higher price for their corn (up 40% last I heard). You have to pay the piper, or at least someone does. It should be obvious that users of corn are paying for the increased prices, the taxes, and such. Have you ever heard of corn starch and corn sweetner? Have you ever noticed how many foods have them? Are you going to notice when practically every food price goes up? Converting food to fuel is not the smartest thing to be done, and that should be obvious. Use switch grass or something like kudzu, or perhaps algae or yeast, but not food.
I understand there is unrest all over the place south of the border among people who depend upon corn for food. A lot of people practically live on beans and tortillas. In Mexico City the price of corn has increased by a third. The peasants are making enough noise the Mexican government is starting to take steps. Of course they will probably do one of the easiest and worst actions they can, and impose price controls.
Meanwhile, we have two new ethanol plants in the next county east, and people so proud of the dozen or so being constructed in the state, that they are practically busting their buttons. Well, it could help the electric car.
The electric car is coming.