While I was trying to design a better, cleaner engine at my old engine manufacturing company, I came to an obstacle: What trade-offs were acceptable? For example, we could make a diesel engine that ran at 33% efficiency, but it was heavy. If we used that engine in an aircraft, the extra weight meant that we needed to carry more fuel, and that made the more efficient engine LESS efficient! Contrary wise, if the engine needed to have a long life, we needed to run it at lower stress levels, so we got less power per pound of engine. If we wanted to produce lower NOx (nitrogen oxides) we needed a lower combustion temperature, but that produced more particulates (unburned fuel in the form of micron-sized bits of carbon in the exhaust). None of that would do. We had to design the engine in the vehicle, as one part of a system, to get the best compromises.
Recently, thinking about how to design a better automobile, I had a parallel revelation: you can’t do much better than we have now without looking at the whole system. To design a better car, you need to start by designing a better road. In fact, you need to take a hard, practical look at the entire transportation system of roads, trucks, byways and the sources of traffic that they connect.
I could start from a clean slate and write a nice piece of speculative fiction here. Perhaps in the vein of Jules Verne and the Nautilus submarine I should do that, but not here, and not today. So, as a matter of practical design, let’s pick some parameters, the constraints that will define the bounds of the system, directions we should go, places we should not visit.
It’s safe to assume the world will stay crowded, land will not be cheap, and money will not be free. None of these assumptions are very controversial, but I want to say up front that they constrain this system.
I do not believe people will move to mass transit systems in great numbers. Mass transit systems require schedules, do not visit remote areas, depend on collection sites, and suffer from what economists call the “the failure of the commons”. In other words, no one puts personal ownership in them. There is no such thing as “my personal bus” or even “my personal seat”. The whole idea is that every component is a mass commodity, meaning it must be plain down to the level of lowest common denominator. It simply does not satisfy the same personal expression of style, comfort and convenience that an automobile does. Can anyone question the attraction of the auto, and the mobile lifestyle it engenders? I’m not one to try and impose such a cultural downgrade, however easier it may make the task of this design. But yes, there will be buses.
Nor am I trying to replace Land Rovers in the Australian Outback with an electric version, or assuming that we will all have flying cars that use ten times the energy of a surface vehicle. I’m sure that a high enough premium on personal time will require some people to have flying cars, but not many.
In the last century the state and federal levels of the United States did a wise thing in creating the wonderful interstate highway system. Urban areas and colorful towns along the older highways, like Route 66, withered and new centers developed around the off ramps to the new highways, as we would expect. Previously, a roadmap looked like the veins in a bloodshot eye. Now, the highways look like planned routes among metropolitan centers, trunk lines feeding the lesser veins and capillaries. There are a few important observations here. Traffic follows a hierarchy of roads, not necessarily the shortest distance but the fastest time between departure and destination. This natural hierarchy tends to depend on the major trunks and spreads out along them. If you build it (the highway) they will come (the connecting roads). We are not seeing many new highways, but we are seeing wider roads and bypasses around cities like New York and Washington, D.C. We are not building new highways through cities very often, the land taking is prohibitive and stretches out to a decade before work can begin. Ramps and cloverleaf intersections abound, and in congested areas they are being built on elevated structures to reduce the real estate needed.
To design better roads I propose a triple-decker affair. The existing highway is on the bottom, and connects to the existing transportation hierarchy. The top level is a two-lane highway, both lanes running in the same direction. The middle level is identical to the top level, but runs both lanes in the opposite direction. There are ramps from the top to the bottom, and from the middle to the bottom. These are not bidirectional clover leafs, just up ramps and down ramps. To make a U-turn, you go down to the bottom level, make a U-turn on the existing cloverleaf, and then take the next ramp to your new direction. Obviously, there needs to be some coordination between ramps and clover leafs.
The new upper tiers of roadway are not just another form of express lane, they are superlanes. Each ramp has electronic access devices that prevent cars that are not equipped from entering the superlanes. On a superlane, the car does not stay between two white lines that tend to get obliterated by passing tires; it follows a continuous white line down the center of each lane. There is no “passing lane” – the second lane is a backup to get around obstacles and allow road maintenance. There is no exit lane – the ramps are on both sides of the road so you can exit or enter either lane. The traffic monitor decides which lane to put you in when you get on, and you stay there, under normal circumstances, until you get off. You will be traveling almost bumper to bumper, and you will be moving at least 100 miles per hour. Each car will be in the “draft” from the car in front of it. That alone will save 20% of the fuel costs. You will not do the driving, the car’s electronics will do that for you, following a wire embedded in the road surface, using adaptive speed control based on microwave diodes in the bumpers. You will not get a flat tire – the tires will not be air inflated, but energy saving flexitires, which I will describe later. You will be routed to an exit ramp based on instructions from your built in GPS and traffic monitoring from the intelligent road sensors. The superlane is designed to be redundant for adaptation to emergencies, providing many forms of alternative routing around breakdowns and emergency situations. And if you don’t happen to have one of these superlane capable vehicles, you can still use the old roads, and they will be a bit emptier each year. You can still drive your new car on the old roads if you want to. There will probably be a toll, automatically billed to your address, but I hope it will be less than the money you save in fuel costs. A superlane highway will carry at least four times the traffic of an ordinary highway in the same real estate footprint. Because it will not require eminent domain to build, it will be faster to implement. It may even cost less.
Now let’s get to the cars.
We can see that they will have radar bumpers and advanced autopilot systems. Flexitires exist now. Instead of an inflated carcass with a fat rubber rim, they have a steel mesh belt supported by radial springs connected to a hub. A thick pad of sticky rubber with siping fits around the mesh belt. It sort of looks like a bicycle wheel on steroids, but unlike a spoked wheel, the springs have resilience, much like an inflated tire. They never go flat. All you ever have to replace is the rubber belt. They have better traction, somewhat like a tank tread. They use a lot less energy because they have less hysteresis and no air to pump up and down on very bump. In fact, the flexitire will save quite a bit of the energy of a moving vehicle because a lot of energy is lost in the flexing of the tire and the heat that causes. A flexitire barely gets above the ambient temperature and gets even better at high speeds.
The motive power will be entirely electric, using currently available permanent magnet motors with neodymium/iron magnets. I see no reason why there cannot be a motor for each wheel, and no transmission will be needed. The motors are tiny, the size of a water pitcher, and capable of 100 horsepower each in short bursts. They will act as brakes, transmission, traction control, active suspension and more, all because they can be instantaneously and individually controlled in microsecond intervals by pulse-proportional control via computers. They will regenerate power during braking, like current hybrids. The weight savings over your usual 400 kilo engine/transmission unit will be yet another source of efficiency. Efficiency is the important word here, and these electric motors convert electricity to motion or the reverse, with an efficiency of 98%. Compare that to a typical gasoline engine with a conversion efficiency of about 23%. Seventy-seven percent of your gasoline dollar now goes out the tailpipe or heats the sidewalk.
Once a car like this is at speed, it doesn’t take much power to keep it there. That’s why superlanes are effective- there is no stop and go traffic. It’s all GO. The car is light – no heavy engine, no transmission, body of carbon fiber and ceramics, LED lights, polycarbonate instead of glass windows, flexitires, and it drafts on the car in front of it. To keep such a vehicle moving on a superlane, even at 100 MPH, will take about 30 HP. I calculate that from the gas consumed by my present car at 75 MPH, with the described extra efficiencies. That is about 22.5 KWH.
To provide that much power for an hour, an ordinary bank of lead-acid batteries would weigh 571 kilos. Multiply that weight by the number of hours you want to travel, because those batteries are going to need at least an overnight charge.
What about flow batteries? They keep their electrolyte in tanks outside the battery and the size of the tank determines the amount of power. A zinc-bromide flow battery will weigh 264 kilos for that one-hour run, and you can recharge it from a tank at your neighborhood recharge station in a few minutes. But it’s still too heavy.
A currently available lithium-ion battery will weigh 115 kilos for every hour you want to ride, but it also needs to be charged, and that can’t happen quickly.
An aluminum-air battery would weigh 22.5 kilos and can be recharged by replacing the plates. You can’t buy one yet, but this will not need not rocket science, just good engineering application of known battery reactions.
It’s pretty obvious that battery technology has a short ways to go. Perhaps fuel cells will get here first. Let’s take a look at them.
The fundamental fuel for fuel cells is molecular hydrogen. Of the various types, the proton-exchange membrane is the most likely to wind up in cars. The protons referred to are the nuclei of hydrogen atoms. The membranes have a short life, but that is a problem that will probably succumb to research. A lot of research right now is being spent on making fuel cells work on something other than hydrogen, such as alcohol, methane or (guess who wants this) gasoline. A NASA grade hydrogen fuel cell can reach a conversion efficiency of over 60%. They can be made small enough to use in cell phones. They would be a wonderful power component for our superlane cars. However, the idea that we already have a gasoline infrastructure (more on this later), so we should not use anything else is bad logic. That gasoline infrastructure has a lot of money to spend on the problem of preserving itself. The best anyone has reported on conversion membranes is an overall fuel cell efficiency of 35%. This is not much better than a good turbocharged diesel engine that can reach 30% efficiency. Personally, I think the money invested in conversion membrane technology is misspent, and would be better applied to developing hydrogen storage and generation technology.
Right now hydrogen can be stored as a gas under pressure or as a “dissolved” component of certain crystals, such as zirconium. A fuel cell simply burns hydrogen with oxygen to form water. The oxygen comes from the air. Each kilogram of hydrogen will release 33 KWH of energy, more than enough to power our car at 100 MPH for an hour. Stored at attainable high pressure, this is a cube the size of a breadbox. We know the storage system works because BMW is running a car on hydrogen right now. However, the container is heavy and we need more than one hour of fuel. BMW has developed the storage, safety and recharge systems, and provides refills at a few stations in Germany.
I have no comparable data for zirconium lattice storage, but I have heard it is promising.
My current understanding is that the real race is between advanced battery systems, like aluminum-air, and fuel cells. We don’t need to pick a winner right now. We do need to note that the common denominator of all the viable systems is a new recharge system, not gasoline, and that means we have to design another system.
The gasoline people are right that an energy solution needs a distribution system. The various developed energy distribution systems on the planet are the electric grid, pipelines and bulk transport. We will not dispense with any one of these, but we must look at the overall pattern of future energy development and the distribution system that will carry it.
There are half a hundred reasonable, clean and cost-effective sources of energy right now. Even coal-fired electric generation plants have their use as base load on the electric grid, and there are very good ways to bury that CO2 and scrub the stack gasses. In a future blog, I will talk about a number of the unusual and some of the better new clean energy sources, but right now we have to choose a direction for future energy distribution that will aid, not limit, future developments.
We observe that alternative energy sources, such as wind and wave power, solar power, and hydroelectric power from stored energy, come in various sizes. A nuclear plant will be perhaps 10 gigawatts or more. A decent pumped water storage reservoir or a flow-battery reserve power installation might be 10 megawatts or less. A moderate wind farm might generate a few megawatts in light air to 500 in a storm. Rooftop solar collectors on large commercial building are in the megawatt range. I run a few solar panels and a small wind generator, and I’m lucky to have it power a refrigerator on a hot day. If we are going to make the best use of current and new sources, we should accommodate them all. That means our energy transport costs have to be very low, very scalable and not require a whole new infrastructure to cover the “last mile” distribution problem. It has to be built on some existing infrastructure. I believe that we will find it best to generate power on the spot where it is most economical and transmit to wherever it will be used, and that an efficient distribution grid imposes minimum cost limitations on that best location. In other words, we get a clean separation between where the power is generated and where it is used, with the distribution system providing the connection.
I propose that the only reasonable power distribution system for houses, autos, and buildings, in other words, for nearly everything, is electricity. It is universal, we can convert it to and from other forms easily and efficiently, and it has unbeatable low transmission costs. How low? To send a KWH from Chicago to Boston, roughly one thousand miles, cost about $.005. Half a cent. And that’s over open wires on high towers in mostly inaccessible areas.
If we are using hydrogen as a fuel for our car, we can get it by splitting water with electricity. If we are using aluminum, we can recover the aluminum from the discharged batteries by passing a current through the solution, so we recycle the aluminum. Both could be done in recharge stations. Of course we can simply recharge lithium ion batteries, but that takes time. Maybe MacDonald’s will have “eat and get charged” emporiums, where we can get a casual hamburger while the old battery gets, um, revolted.
Let’s visualize a Brody Boys hydrogen filling station:
Sitting in an acre of asphalt is a huge canopy roofed in solar photovoltaic cells. There is also a water pipe (or a rain barrel – that would be enough) and a connection to the power grid. On sunny days, the solar panels make hydrogen and oxygen. Nights and cloudy days the grid runs the splitter. The hydrogen is compressed, cooled, compressed again to about 5000 PSI, and stored in underground tanks. You pull up and connect a pressure hose to your inlet flange, heave on the clamp to make it gas tight, and insert your personal code for the credit. The car has already told the pump how much you need and what your banking connection is. The pump shuts off automatically, displays your total and you disconnect. Meanwhile you are rather exhausted from the trip through downtown and looking forward to the relaxation of the superlane, so you go inside to the oxygen bar for a few whiffs. Maybe you want some coffee or green tea, have your blood pressure and retinas checked, and now that you know you are in top shape for the drive, off you go. Thanks and please come back soon.
You’re up the ramp, onto the superlane to the airport, and you can turn the seats around and have a nice, face-to-face chat with your family.
Of course, the solar panels in the canopy only generate a little power, and certainly not enough for the trade on a busy day. In fact, the entire existing electric grid cannot generate a tenth of the power needed for this scenario. So we need to design a proper energy grid. Everyone knows we need work on the energy grid. But for what? What are our design parameters?
The United States electric grid is a manually controlled, hierarchical, alternating current system with components originally designed by Nicolai Tesla and sold to George Westinghouse. Currently, it sends power from huge steam turbines producing tens of megawatts each at about 25,000 volts to population centers over naked lines at voltages up to 765,000 volts. The advantage of the AC system over Edison’s direct current system was the cost savings in power distribution. DC could not, in those days, change voltage, so the wires had to made thick and heavy to carry all the current at the same voltage households could safely use it. Meanwhile, by using transformers, AC systems could boost that voltage a thousand times and reduce the size of the wires needed in proportion. Edison needed a lot of small generators close by to his customers. Westinghouse could build enormous, efficient plants out in the boonies and transmit the power cheaply.
There are some drawbacks to AC. Generators, in fact any power source on the lines, has to be phased the same as everything else or there are serious problems. A badly phased generator can bring down the system. Also, in AC, voltage and current can get out of phase with each other when there are large inductive loads, such as huge motors, or when there are capacitive loads, such as particle accelerators. These differences are called “power factors”. Adverse power factors can dim the lights and cause the generators to spin without putting out power. There has to be elements in the net to balance the power factors. Also, AC lines radiate radio energy, make a lot of radio noise, the high voltages can cause corona discharge, and the system is not very forgiving. That’s why the power companies don’t like household energy producers. Phasing, power factors and fragility do not outweigh transmission costs, however. Costs rule.
The US grid, and Europe’s grid, looks like a plate of spaghetti thrown against the wall. They grew with each new power generation source or electrification project. What we need is a US Highway System for the electric grid. In fact, why don’t we just use the US Highway system? Once we have a plethora of sources of various sizes, they will tend to cluster along the same routes of human habitation as transportation corridors, for the same reasons. Land is scarce, and firebreaks along the paths of high-voltage transmission lines may not be the best ways to manage wilderness areas. Most important, these new electric vehicles, however they are powered, will more than triple the load for electrical transmission, and they will need to follow the superlanes, not the existing transmission routes. So let’s see what a superlane does for electricity.
In order to provide a robust path for large amounts of power to the new cars, we should embed a specialized set of top-level transmission lines in the highway structure. The cables would be a cable cluster of multiple sets of three-phase 000 size aluminum wires with the newest and best XLPE (cross-linked polyethylene) insulation, suspended under the upper roadbed with a duplicate backup cable on the other side of the roadbed. Each cable cluster would have two fiber optic channels that will provide lightning and EMP-proof command and control signals for the electronic switches and power transformers installed at intervals along the roadway base. Through substations and sub-substations, most of which are already in the system, the lowest level stations will observe and detect phasing and power factors, load and heat, and connect through (mostly) fiber optic channels to the intelligence in the main stations under the superlanes. These superlane cluster cables will operate at 500,000 volts AC, three phase. These were chosen to match current cable technology and provide robust, trouble-free massive power transmission. Each triplet can carry about 25 megawatts, and a cluster will have ten or more triplets.
I understand that this will not completely solve the instabilities with multiple sources of power. Yet I don’t want to stymie innovation simply because of the impracticality of making a connection to the AC power grid. Therefore I am proposing an “Edison compromise” DC power bus of aluminum plate embedded in the underside of the roadway. Modern high-power semiconductor components can switch DC to AC at moderate but increasing power levels, so the limitations that won Westinghouse an empire do not entirely rule today. All batteries work on DC. Most solar applications generate DC, not AC. There are no phasing problems with DC. There are no power factor problems with DC. DC does not radiate radio energy. A pair of parallel DC plates will not create large external magnetic fields to affect compasses and electrical components. These DC busses are not the major carriers, but subordinate specialized carriers for those purposes.
So we can see how the systems level approach has wound up creating not just a new car, but also a new transportation system for vehicles and energy.
Next blog we catalogue a few interesting inventions that fit this scheme.
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