3 ตุลาคม 2562
By Dr. Fred Schlachter
Lawrence Berkeley National Laboratory (retired)
American Physical Society (retired)
ThEP Center (advisor)
Global climate change threatens most countries in the world, including Thailand, with disastrous consequences. Approximately 1/3 of CO2 emission, which is the primary cause of climate change, is due to transportation, reducing our current reliance on combustion of fossil fuels is a major target for implementation of new technologies. Changing societal priorities as well as new technologies are leading us to a revolution in transportation.
There are two related issues: how to power vehicles without the use of fossil fuels, and rethinking how to meet our transportation needs. Both issues will be discussed.
Cars require a portable fuel. If we are not going to rely on combustion of fossil fuels, with their very high energy storage density, then we must consider options. Although many possibilities have been considered, by far the best is powering cars using electricity stored on-board in batteries. Other potential options, such as supercapacitors and hydrogen fuel cells, are highly impractical for a variety of reasons which will not be discussed here.
Electric cars are not new: the great inventor Thomas Alva Edison drove an electric car, as did King Rama V of Thailand.
King Chulalongkorn (Rama V) owned a 1903 Baker electric car.
Changing to electric vehicles (EV) has many implications: a new infrastructure for distribution of electricity and for charging vehicles, greatly reduced air pollution, and the need for space and locations for charging batteries.
Batteries for storage of electricity have been known since the invention of the lead/acid battery in the middle of the 19th century. They are still used to start internal-combustion engines. However, they are too heavy and have low energy-storage density, and are thus not useful for powering cars. Several other battery chemistries have followed, Including Nickel Cadmium and Nickle Metal Hydride. However, a new battery chemistry, developed in the late 20th Century, is lithium-ion batteries. Li-ion batteries are light in weight and have a relatively high energy-storage density. However, the energy-storage density is much less than that of gasoline, they generally require the element cobalt, which is in short supply in the world, and most of which is mined by child labor in the Democratic Republic of the Congo. They are prone to catching fire, in which case they burn with very intense heat. And cars with Li-ion batteries have a limited range, usually less than 200-300 km. They are also expensive, and have a finite lifetime. Since there are no new better battery chemistries on the horizon, we will have to accept the high cost and limited range of present-day electric cars, of which there are many models. We also have to accept that charging time for a battery ranges from an hour to half a day.
EV is powered by batteries placed beneath passenger seats.
The infrastructure needs and place for charging are particularly difficult in Thailand, at least in major cities, where even finding a place to park can be difficult. People who live in apartments will have a difficult time in finding a location to charge their car, unless their apartment building has dedicated parking and EV charging capabilities.
Charging EV needs space and proper utility access.
How can EVs of middle-class people living in major cities be charged over night?
Electricity generated from a “green” source will be required for slowing and improving global climate change. That means energy from wind and solar generation, and, in some cases, hydroelectric is needed. The plot below shows slow improvement in energy-storage density of Li-ion batteries, although this rate of progress is not sure to continue. The decrease in cost is primarily driven by market forces, and manufacturers in China, Japan, Korea, and other countries battle for market share, perhaps even selling batteries below the cost of manufacturing them.
The introduction of electric cars will have the beneficial effect of reducing CO2 to the atmosphere, but will not help alleviate traffic or parking issues. One possible approach is to improve public transportation, as in the BTS and MRT in Bangkok. This, however, is a very expensive process, and takes time plus political will. Public transportation is also most beneficial in large cities, with their high population density. This limits the number of cities where public transportation is a viable option.
Traffic jam in Bangkok. BTS public transportation in Bangkok.
Another approach to improving traffic and parking is to replace motor bikes, tuktuks, and other gasoline-powered small vehicles with electric versions using Li-ion batteries. This approach is common in China, which manufactures and sells many versions of electric scooters, bicycles, motorcycles, and other similar electric vehicles. This would greatly reduce the contribution of vehicles to global climate change.
E-motorcycles Segway: Suvarnabhumi airport E-scooters
E-bikes tours: Chiang Mai Electric tuktuk: Philippines
Many versions of electric personal vehicles are becoming available, and will replace vehicles powered by fossil fuels and internal-combustion engines.
A very promising approach to reducing CO2 emission and to improving parking and traffic is to abandon private ownership of a car and to use a summon-on-demand service like Uber or Grab. The summoned vehicles should be electric. Range is not an issue in most cases, as the battery can be recharged as needed and a different car with a fresh battery can be substituted. This approach greatly reduces the capital cost of car ownership as the car can be used all day and night except when recharging. It will reduce the number of cars on the road and improve parking.
An even better and more advanced approach will be to use autonomous vehicles (driver-less cars) for summon-on-demand transportation. There are of course major safety issues, especially on the crowded roads and sois in major cities, and questions of liability. However, autonomous vehicles will be more safe than human-driver cars, as computers do not smoke, drink, eat, text, or suffer from various distractions.
Human drivers are easily and often distracted from paying attention to the road, resulting in severe risk of accidents. Computers are not distracted.
Relaxing in an autonomous vehicle, navigated by an on-board computer.
The new technology of automobiles developed around the beginning of the 20th century disrupted and replaced animal-powered transportation. Now electric-powered cars are replacing cars powered by fossil fuels. Additional disruption is coming from summon-on-demand vehicles, and eventually by autonomous vehicles. Similar disruptions can be foreseen in air travel, with drones and electric-powered planes. We are in the midst of a transportation revolution.
The future of transportation is thus likely to involve an almost complete elimination of fossil-fueled cars with internal-combustion engines, eventually even trucks, and replacement of existing small vehicles with electric versions. There must be improved public transportation, and eventually reduction of private ownership of cars, to be replaced by summon-on-demand vehicles, electric of course, and autonomous vehicles as technology continues to improve.