The development of new, stronger, a

The development of new, stronger, and improved rechargeable battery systems is to a large extent politically motivated and driven. Governments in many industrialized countries and regions (particularly in California) are interested in “pollution free”, or at least pollution-reduced vehicles. Rechargeable batteries as a sole energy source for propelling cars are often considered to be the solution. However, one has to take into consideration that the electricity required for charging the batteries need to be produced first; this occurs generally in power plants which utilize mostly coal, petroleum, or natural gas as fuels. (50% of the electricity in the USA and Germany is produced by coal, in contrast to 81% in China, 68% in India, and 5% in France, amounting to 41% as world average). These power plants also emit CO2 and other pollutants (sulfur, mercury, nitrogen) into the atmosphere. One should also keep in mind that transmission losses to the consumer, losses when charging batteries (about 50%), and consumed energy to manufacture batteries may contribute likewise, in an indirect way, to energy consumption and pollution. The same is true for solar energy systems and atomic reactors (with all their problems) which need years to reach the break-even point at which energy consumption for production and emission of pollutants are compensated. In this respect, the specific energy contained in gasoline or Diesel oil (about 12,000 Wh/kg) does not look too bad. The cost per mile derived from electricity stemming from a household outlet is higher than that obtained using a Diesel engine. Moreover, Diesel engines can be made so energy efficient and pollution-reduced today that they compare quite favorably with (more expensive) hybrid automobiles (that utilize a gasoline back-up engine for recharging the battery and capture the energy, evolved from braking. This makes particularly sense for inner city traffic with frequent stop and go maneuvers). Some consideration should also be given to the distance one can drive before recharging of the battery is required which for lead-batteries is about 60 km (37 miles), and about 40–80 km (25–50 miles) for a lithium-ion battery, weighing each between 300 and 400 kg. These values are reduced in cold weather when electric heating is required. In short, matters do not look as favorable for battery-propelled cars as some proponents want us to believe (except for niche markets such as intercity delivery and utility repair trucks). This does not mean that new energy sources will not be found and used in the future (e.g. fusion). Conservation of energy and electrically propelled public transportation systems seem to be among the better alternatives. Finally, batteries are not the only available storage devices for energy, particular for smoothing out energy peaks. Among the alternative storage devices are super-capacitors (10 Wh/kg), flywheels, superconducting magnetic energy storage systems, electrolysis of water in combination with hydrogen fuel cells (1,100 Wh/kg), flow batteries, and reservoirs in which water is pumped up during off-peak hours.