Is the Electric Car Mature?

Cars with electric drive trains have been around for more than 100 years. At the turn of the century in 1900, a car buyer had three choices of propulsion systems: electric, steam and internal combustion engine, of which the IC engine was the least common.

The electric cars appealed to the upper class and the vehicles were finished with fancy interiors and expensive materials. Although higher in price than the steam and gasoline-powered vehicles, the wealthy chose the electric car for their quiet and comfortable ride over the vibration, smell and high maintenance of the gasoline-powered counterpart. Best of all, EV (electric vehicles) did not require changing gears, the most dreaded part in driving a gasoline car then. Nor did the EV need manual cranking to start the motor, a task the upper class did not want to be seen doing. Since the only good roads were in town, the limited range of the EV was no problem and most of the driving was local commuting. The production of the EV peaked in 1912 and continued until the 1920s.

The battery choice was lead acid, and for an up-price the buyer could fit the Detroit Electric with nickel-iron (NiFe), a battery Thomas Edison promoted. NiFe has a cell voltage of 1.2V, was robust and durable even when over-charged and fully discharged. Being a good businessman, Edison advocated NiFe over lead acid but the popularity for this battery began to decline after a fire destroyed the Edison factory and laboratory in 1914. NiFe provided only a slightly better energy density to lead acid and was expensive to manufacture. In addition, the battery performed poorly at low temperature and the self-discharge was 20-40 percent a month, considerably higher than lead acid.

Detroit Electric, one of the most popular EVs then, were said to get 130km (80 miles) between battery charges. Its top speed was 32km (20 miles) per hour, a pace considered adequate for driving. Physicians and women were the main buyers. Thomas Edison, John D. Rockefeller, Jr. and Clara Ford, the wife of Henry Ford, drove Detroit Electrics. Figure 1 shows Thomas Edison with his 1914 Detroit Electric model.

Batteries play an important role in electric powertrains and the price per kilo-watt-hour varies according to battery type. Table 1 lists typical batteries for mobility, and at $160 per kWh the starter battery is most economical, followed by the forklift battery. Newer technologies are more expensive and this is due to costly raw materials, complex manufacturing procedures, and electronic safety and management systems. Higher volume production will only moderate the price marginally.

Cost cutting as part of mass-production by Henry Ford and the invention of the starter motor in 1912 moved the preference of car buyers to gasoline-powered vehicles. By the 1920s, intercity roads required long-range vehicles and the discovery of Texas crude oil made gasoline affordable to the general public. The EV became a thing of the past until the early 1990s when the California Air Resources Board (CARB) began pushing for more fuel-efficient and lower emission vehicles and mandated the zero-emission car.

It was the CARB zero-emission policy that prompted General Motors to produce the EV1. Available for lease between 1996-1999, this early electric vehicle run on a 18kWh lead acid battery that was later replaced with a 26kWh NiMH pack. Although the NiMH battery gave an impressive driving range of 260 km (160 miles), the EV1 was not without problems. Manufacturing rose to three times the cost of a regular gasoline-powered car and in 2001 politicians changed the CARB requirements, which prompted General Motors to withdraw the EV1 to the dismay of many owners. The 2006 documentary film “Who Killed the Electric Car?” gives a mixed impression of government-induced programs for cleaner transportation.

To match the convenience of an IC powered vehicle, the EV needs a battery capable of delivering 25-40kWh. This is twice the battery size of a PHEV and ten-times that of the HEV. The electrochemical battery is not the only added expense; the power electronics to manage the battery make up a large part of the vehicle cost. An EV without a battery is roughly the same cost as a traditional gasoline-powered car. Figure 2 shows the battery of the Nissan Leaf removed and as part of the installation.

24kWh lithium-ion battery with a driving range of 160 km (100 miles) of city driving. The battery fits under the floor and seats of the car. (Courtesy of Nissan Motors) Another concern with the EV is it’s driving range, especially in cold and hot weather. Designed to go 160 km (100 miles) on a charge, a BMW electric Mini traveled about half that distance in cold weather. Beside the added energy drawn to heat the cabin, battery performance drops in cold temperatures. To conserve energy, EV drivers should use the heat and air conditioning systems sparingly and drive in a reasonable manner.

It will take a day to fully charge the electric Mini on a regular 115AC outlet. High-power outlets can reduce the charge time to 3-5 hours, and public fill-up stations can charge a battery in two hours. The electrical outlet, not the battery, governs charge times. Charging a 40kWh battery in six minutes, as some battery manufacturers might claim, would require 400kW of power. An ordinary 115VAC electrical outlet provides only 1.5kW and a 230VAC, 40A kitchen stove outlet delivers 9kW.

Car manufacturer Tesla Motors focuses on building EVs that generate zero-emissions with very high performance. The Silicon Valley roadster boasts a zero to 96km (zero to 60 miles) acceleration time of 3.9 seconds. The 7000 Li-ion cells store 53kWh of electrical power and promise a driving range of 320km (200 miles). Liquid cooling prevents the pack from exceeding 35°C (95°F). To achieve a five-year warranty, Tesla charges the Li-ion cobalt cells to only 4.10V instead of 4.20V/cell, and electronics circuits inhibit charging in freezing temperatures. At $130,000, this car turns heads and becomes a discussion item, however, the $40,000 of a replacement battery could causes concern for long-term owners.

Batteries for the electric powertrain currently cost between $1,000-1,200 per kWh. According to The Boston Consulting Group (BCG), relief is in sight. They claim that within the next decade the price of Li-ion will fall to $750 per kWh. Meanwhile, batteries for consumer electronics are only around US$250-400 per kWh. High volume, automated manufacturing, lower investments in safety and shorter calendar life makes this low price possible. BCG predicts that Li-ion batteries for the powertrain will eventually match these consumer prices, and the cost of a 15kWh battery will drop from $16,000 to about $6,000. The largest decrease in battery prices is expected to occur between now and 2020, with a more gradual decline thereafter. According to BCG, the anticipated calendar life of the battery will be 10-15 years.

E-One Moli Energy, a manufacturer of lithium-ion cells for power tools and electric vehicles, says that the cost of Li-ion can be reduced to $400 per kWh in high volume but the peripheral electronics managing the battery will remain high and this added cost is know to double the price of a pack. Reductions are also possible here and E-One Moli Energy predicts that the electronics will only make up only 20 percent of the battery cost in five years. These forecasts are speculative and other analysts express concern that the carmakers may not be able to achieve the long-term cost target without a major breakthrough in battery technology. They say that the current battery cost is 3-5 times too high to appeal the consumer market.

Driving on electricity is cheaper and cleaner than burning gasoline, but at today’s low fuel prices, uncertainty regarding the service life of the battery, along with unknown abuse tolerances and high replacement costs will lower the incentive for buyers to switch from a proven concept to an electric vehicle. Technology Roadmaps Electric and plug-in hybrid electric vehicles (EV/PHEV) says that if a driver wants a 500 km range between fill-ups achievable with an IC powered car, the battery would need a capacity of 75 kWh. At an estimated $400 price tag per kWh, such a battery would cost over $30,000 and weigh nearly a ton. Figure 3 illustrates typical battery sizes used in cars with different powertrains.

Figure 3: Typical battery wattages of vehicle batteries. The starter battery has about 720W; hybrid 1500W; plug-in with 12.5kW and a light electric vehicle 25kW

Roadmap compares the energy consumption and cost of gasoline versus electric propulsion as follows: The EV requires 150-200Wh per km, and at a consumption rate of 200Wh/km, and an electricity price of $0.15 per kWh, the fuel cost to drive an EV translates to $0.03 per km. We compare this figure with $0.06 per km for an equal-size gasoline-powered car and $0.05 per km for diesel. This price does excludes equipment costs, service and eventual replacement of the battery and engine.

The EV market attracts innovative companies to develop a better battery and many are taking advantage of generous government incentives offered, but there is a danger. For the sake of optimal energy density, some start-up companies are experimenting with aggressive design concepts using volatile chemicals that compromise safety. They push the envelope by announcing impressive advancements, emphasize only the pros and squelch the cons. Such behavior will get media attention and entice venture capitalists to invest, but hype does little in finding a lasting solution to improve existing battery technologies.

The battery will determine the success of the EV and until major improvements have been achieved in terms of higher energy density, longer service life and lower cost, the electric powertrain will be limited to a small niche market. While governments are giving large contributions in the hope to improve current battery technologies, we must realize that the electrochemical battery has limitations. This was made evident when motorists tested eight current and future models with electric powertrains and attained driving ranges that were one third less than estimated. Table 4 lists a rundown. The vehicles were tested in real life conditions on highways, over mountain passes and under winter conditions. The information was collected at time of writing.

Table 4: Electric vehicles with battery type and driving range.
The travel distance is less than advertised; battery aging will shorten the range further.

The environmental benefit of driving an EV will be minimal unless renewable resources provide the electricity to charge the batteries. Burning coal and fossil fuel to generate electricity simply shifts the pollution out of congested cities to the countryside. In the USA, electricity comes from burning 50 percent coal, 20 percent natural gas, 20 percent nuclear, 8 percent hydro and 2 percent solar and wind. One of the advantages of the EV is charging at night when the power grid has extra capacity.

Going electric may create another dilemma, which begs the question, “In the absence of fuel tax, who will pay for the maintenance and new construction of highways?” Roads cost governments billions to build and repair, and EV drivers will be entitled to use them for free, a gift that needs to be compensated with higher taxes. This poses an unfair burden for those taking public transportation as they pay double: tax for highways and the fair for bus or train. Raising road tolls may be an alternative.

The high cost of the EV against the lure of cheap and readily available fossil fuel will make the transition to a cleaner way of living more difficult. Government subsidies may be needed to make “green” cars affordable to the masses. Many argue that this handout of public money is unfair and suggest that the tax dollars should go to building more efficient public transportation systems.

The goal of governments should be to remove cars from the roads by offering other modes of transportation. Commuter trains are one of the most efficient alternatives in moving people comfortably and fast. Changing the focus away from cars would, for the first time in 100 years, hand our cities back to the people who are the rightful owners. Such a change in direction would make cities more enjoyable and future generations would thank their forefathers for prudent planning. It’s interesting to note that some of the nicest cities were built before the invention of the car. During this time, designers had the movement of people in mind and this was done out of necessity rather than foresight. Most of these desirable cities are in Europe, and North America appears to be trailing behind.