100 MPG (City-Driving) Electric Car?
Attempts by established automobile manufacturers to design and produce practical, economically viable battery powered cars have so far all failed and will most likely continue to fail.
The reason is twofold. First, the vast majority of people in this industry, tasked to design, produce and sell battery powered cars, believe in their hearts they are being coerced into advancing an inferior product. Second, most people believe that owning an automobile provides them with freedom and independence. Pure battery electrics would deprive them of a big chunk of that freedom and independence.
Hybrids, such as the Toyota Prius, etc., are aimed at armchair environmentalists. They represent good PR but otherwise serve no useful purpose. Running gasoline engines over a wide rpm range is grossly inefficient.
The Chevrolet Volt is about 75% on the right track, the remaining 25% is horribly wrong. It is a sheep in badly fitting wolf's clothing. Designing electric in terms of simply adapting conventional automobile technology is narrow minded. These are the same people who used the EV1 project from 1996 to 1999 to "prove" electric cars don't work. Take Elon Musk out of the Tesla equation and gravity simply takes over. A Tesla requires much more electricity to recharge its batteries, per day, than an entire North American household consumes per day.
Electricity generation and distribution infrastructures are able to cope with a fraction of a percent of the total population of automobiles running on battery power. If 20% of existing vehicles on the road were to be replaced by battery-electric, the number of coal and nuclear power stations to handle the battery powered automobile and truck population would need to be doubled. There are vested interests. Green environmentalists and petroleum producers will oppose the building of power stations on such a large scale. Politicians and high flying entrepreneurs are mentally wired to ignore all of this.
Lithium batteries will become more, not less expensive. Moore's Law applies only to semiconductor chips. Lithium technology has been incubating too long. Governments of producing countries, commodity traders and arbitrageurs are expecting demand for lithium to go up and will sink their teeth inexorably into every facet of its supply. (See lithium carbonate spot price, image at bottom of page).
It is popularly believed that the main drawback of electric car batteries is technical - insufficient energy storage capacity. Surprisingly, this is not so. Their principal disadvantages are glaringly obvious. Firstly, the existing technology requires only a few minutes to fill a tank with gas. Ninety-nine percent of drivers do not have any inclination to search for an elusive charging facility and then to wait seemingly forever to charge the battery. Secondly, the trade-in value of pure-electric cars is far below that of equivalent gasoline and diesel powered vehicles.
Hydrogen fuel cell powered cars are quick to refuel but they are not the answer. There is plenty of hydrogen all around us but not in a form that is readily available as a fuel. Hydrogen as a fuel is expensive compared to gasoline and electricity. Hydrogen generation is horribly inefficient and hydrogen conversion to electricity is also horribly inefficient. Hydrogen is extremely dangerous. It can only be made into safe fuel by artificial means. Fuel cells are relatively "highly-strung", not an easy fit into everyday motoring situations. Hydrogen is promoted by people who cling to the absurd notion that a vehicle propulsion system that gives off only water will help save the planet. High volume hydrogen production is a carbon-dioxide-producing smokestack process.
Batteries do not last very long compared to automobiles. Used car dealers are well aware that battery powered car owners are most likely to want to trade in their cars just before the batteries wear out. A replacement battery for pure-electric automobiles costs, on average, $15,000. (A Tesla battery costs twice as much!) Secondhand batteries have only scrap value on the open market.
Prospective second hand buyers would obviously insist on a very sizable reduction in the price of the car to help pay for a new battery. The makers of pure-electric cars are doing everything in their power to disguise this. Extended payment terms, battery leasing and battery-exchange charging stations are smokescreens designed to hide the real costs. Subsidies are stopgaps that will inevitably run out. If we are not careful, we could end up with car lots filled with rusting, unsold, very unwanted, pure-electric cars.
Pure electric, at double the price, half the range can never be viable. A brand new electric configuration that has double the range, half the fuel consumption can be viable.
The type of vehicle proposed below would use a integrated super-capacitor/ lead-acid battery, in which the capacitive aspect handles the peak currents, while the lead-acid aspect handles the somewhat more modest average currents. The reduced workload on the lead-acid helps to maximize service life. This, in turn, would help to create not only a successful item of commerce but would help to put an energy efficient, environmentally sound vehicle on the road. Consumers instinctively prefer user-friendly technologies that strike a good balance in every way possible.
What we need are economical people carriers. Definitely not futuristic looking, above all practical, easy to get into and out off, inexpensive to manufacture - not to compete but to co-exist with conventional internal combustion engined cars. For regular and second car use, seating the equivalent of four adults. With air conditioning. Powered by specially developed lead-acid batteries, driven by specially developed alternating current electric motors.
This type of vehicle would use regenerative braking - controlled exclusively via the accelerator pedal. Push down to go faster and release to provide excellent "overrun" braking all the way to standstill. This is one-pedal driving - an absolutely brilliant concept. The position of the accelerator pedal no longer merely controls the speed but tells the vehicle at what rate it should accelerate, maintain an even speed and at what rate it should decelerate. It takes only a few minutes to master. The brake pedal is used only for emergency braking and to hold the vehicle when at standstill.
Maximum speed of at least 100 miles per hour and a range of 10 miles, possibly less. There won't be any range-anxiety. The vehicle would have a superbly well developed, 50%-plus efficient, constant speed, scientifically silenced, internal combustion engine driving an alternator, that would be started only when the vehicle begins to run out of range, to recharge the batteries, to go another 800 miles, at a fuel consumption in stop-start city driving of at least 80 miles per US gallon - which equals 96 miles per imperial gallon, 2.94 liters per 100 kilometers. (Automobile engine efficiency under normal driving conditions is usually less than 10%. That is low! An ideal opportunity for the industry to finally successfully adapt the gas turbine to the automobile!)
The electric motor would be rated at 100% - but the internal combustion engine would only be rated at about 50% of the power of a conventional automobile engine, with not the slightest reduction in performance during acceleration and climbing hills. A battery can very easily accommodate these types of peak energy demands. This concept was invented by Ferdinand Porsche in 1899.
It would be possible to define this kind of vehicle as:
- Driven by internal combustion engine, with extra efficient electric transmission;
- Battery powered, with extra efficient internal combustion engine range extender;
- Focused primarily on fuel economy by a careful blending the natural strengths of internal combustion and the natural strengths of electric technologies.
This constitutes a genuine groundbreaking, eco-friendly, next-generation technology, in many respects similar to diesel-electric locomotive, very large mining truck and most of today's ocean liner propulsion systems. Constant speed diesels "in the front" and valiable speed electric motors "at the back". Stop-start driving makes gasoline engines less than 10% efficient while electric motors can run at 80% efficiency.
The 2014 Formula 1 regulations require racing cars to have 1.6 liter engines and to use regenerative braking. The 2 megajoules of energy stored during braking, per lap, will add 161 horsepower, (120 kilowatts), to the rear wheels for a total of about 30 seconds to accelerate the vehicle back up to speed. The FIA objective is to convert as much of the chemical energy in the fuel into mechanical energy as possible, in an attempt to make racing meaningful in terms of every day automobile use. The technology for electric transmission is in the process of becoming a reality.
The battery would, out of necessity, need to be at least 180 volts. The motor rated at least 125 volts, three-phase. Peak battery current about 250-350 amps. The motor control unit would typically employ digital/microprocessor three-phase, "six-pack" modular IGBT inverter technology. The master controller would include an analog current limiting and speed control combination, automatically adjusting the current flowing to, or coming from the drive motor, tailored to respond to the position of the accelerator pedal.
It is essential for the battery to be a liquid electrolyte type, (also known as flooded), with lead-antimony positive grid and lead-calcium alloy negative grid technology. The negative plates would be based on a special high-carbon design. This combination permits high discharge/recharge currents, makes the lead-acid battery abuse resistant, keeps the price down and at the same time provides roughly four times longer life than comparable maintenance-free batteries. Battery lids would include integral water refill control valves, fed via a single water supply connector. (Maintenance-free lead-acid has a limited life expectancy when deep cycled and is a bad choice for electric cars. It is available, it is being used - it owes its existence to perceived market demand and engineering compromise, not to technical ingenuity. If tire pressures, oil and radiator water need to be checked from time to time, why not battery water?)
The switch-on routine would include engine preheat. The electric motor would be water cooled and the heated water from the electric motor would be circulated via the internal combustion engine, bringing it up to operating temperature before engaging the cooling radiator. The cooling system would be controlled by valves so that with the engine running, the cooling system would switch to separate the electric motor and the internal combustion engine cooling circuits. This would mean no more cold weather starting problems, help to cut down emissions and maximize engine life. The engine would charge the battery up to 80% state-of-charge, running at constant speed and delivering constant power at maximum efficiency, then stop. This helps to reduce engine emissions and reduce battery water consumption. The battery would be charged from 80% up to 100% from the electricity network.
The ideal engine for this purpose is likely the Gasoline Direct-Injection Compression Ignition (GDCI) - a gasoline engine that uses no spark plugs. The engine looks fairly normal on the outside but not on the inside. The pistons have soup bowls cast into their crowns and injectors squirt fuel into the exact center of each bowl. GDCI achieves auto ignition by heating intake air with carefully controlled amounts of exhaust gas followed by squeezing the mix with a 15:1 compression ratio. Injecting a small dose of gas just before top dead center, and the main fuel squirt just after that point, yields cylinder pressures that rise far more gently than those found in any diesel. This improves efficiency, since combustion pressure pushes only against a descending piston. Fuel-injection pressures are only a fifth of what’s required in a diesel, yielding major savings in cost and quieter operation versus diesels.
The vehicle would normally be plugged into a 240 volt ac outlet overnight and left plugged in until the vehicle is needed. Days, weeks, months, without the slightest risk of overcharging. Charging from 120 volts is possible but would take significantly longer than overnight. Fast recharging stations and hydrogen powered cars are impractical concepts dreamed up by people who cherry pick specifications without the benefit of actually understanding the technologies in question.
The writer built a battery powered car in 1980, by converting a Renault 5 to electric power. The car had a 20 hp (15 kW) electric motor, had regenerative braking, carried 550 lbs (250 kg) of batteries and had a range of 47 miles, (76 km). Absolutely magnificent to drive, especially in heavy stop-start traffic. People were not ready for electric cars at that time and the project was shelved. The knowledge gained lives on.
Evolution is a relentless force not simply confined to biology. Countries evolve. Economies evolve. Businesses evolve. Technologies evolve. Evolution is subject to the simplest of all rules - survival of the fittest. All of us receive invitations to come along for the ride, yet none of us will ever receive permission to occupy the driver's seat.
The biggest battery manufacturer in the world and the biggest automobile manufacturer in the world were forced to apply for Chap. 11 bankruptcy protection in the wake of the 2008 world-wide financial debacle, yet their managements remained curiously oblivious they were actually paying an evolutionary penalty for failing to properly update their century-old technologies in line with the rising cost of fuel and raw materials, and for wantonly misunderstanding the consumer.
This presentation was written in 2013, (updated Jan 2016), and attempts to provide an outline of a new way of looking at automobile design, in touch with the consumer, in touch with the environment, in touch with technical feasibility and in touch with economic reality.