In the last decade there has been a significant increase in public awareness of the need to conserve energy, recycle waste, and make lifestyle choices that are environmentally friendly. Many companies have jumped onto the “green” bandwagon, adopting slogans or advertising campaigns that emphasize the company’s proactive involvement in the environmental movement.
The automobile industry is at the forefront of this juggernaut, as is particularly evident in the case of Toyota’s introduction of the Prius and the advertisements that emphasize how the car is environmentally friendly.
The ability to make manufacturing and energy production “green” is at best a complicated issue; however if taken in incremental steps it becomes somewhat more tractable. In the case of the automotive industry, perhaps the most significant changes that can be made are those that relate to using energy more efficiently, thereby reducing the aggregate annual consumption of fuel.
The approach is really a very common sense method that dictates that systems must be designed with efficiency as the primary objective. This is more difficult than one might imagine; many ideas that appear as positive changes, such as the use of gasohol, are actually a step in the wrong direction. In the case of alcohol blends, the energy cost of the alcohol exceeds the energy cost of ordinary gasoline; it takes more energy to produce a gallon of gasohol than is required to produce a gallon of gasoline. The net result is higher expense and less efficient operation as the blends get fewer miles per gallon, driving overall fuel consumption higher.
One of the more promising approaches is to use hybrid power plants, typically consisting of an internal combustion engine operating in concert with a battery bank or a fuel cell. The resulting power plant is far more complicated than the engine of a traditional gasoline powered automobile; the complexity is in large measure due to the much more sophisticated control system that is required to make the two power sources work in harmony.
Such hybrid power plants would not be possible were it not for the microcomputers that are the basis of the control system. Once the basic hybrid power plant is developed, the next logical step is to make it as efficient as possible by including an energy harvesting system, that is taking advantage of energy that is otherwise wasted, such as the heat that is dissipated in the braking system of a car. Such systems harvest the otherwise unused energy to help power the car.
Once again, however, there is an engineering price to pay to design a control system that will allow a regenerative braking system to function and to function safely. It must be designed to operate in a safe manner including the possibility of a system failure. Regenerative braking systems consist of both an electric brake and a mechanical brake working in concert with one another. The synergistic system has built-in redundancy to ensure safety, and the controller directs the regenerative energy produced to a storage element, which is then used to assist the vehicle as it accelerates from the braking scenario, whether it be a full stop or just a slowing down of the vehicle.
Regenerative braking is a good idea, but more complicated to implement than one might think; it also exemplifies the need for new products to meet the needs of an energy efficient society. There needs to be an efficient way to store the energy that is produced in the regenerative braking process.
Ten years ago there was nothing commercially available to meet the needs of a regenerative braking system. Today the problem can be solved using a relatively new device, the ultracapacitor, which can store an immense amount of energy and has a response time far faster than a battery. The use of a battery in a regenerative system would severely limit the amount of energy that could be stored due to the slow charging rate of the battery, however this problem is eliminated using capacitors, as the rate of charge is very rapid, allowing the amount of regenerative energy stored to be much greater.
Every forward step in making the automobile supply chain green requires energy efficient engineering, the development of products that are designed with energy conservation in mind, and the use of materials that are themselves environmentally safe. The ultracapacitor mentioned above is an example of just such a product. Not only can ultracapacitors be used in a regenerative braking system, they can also be used in concert with the starter battery of a traditional car or the battery pack of an electric car. Using them in parallel with the battery or battery pack makes it possible to use fewer batteries or lighter duty batteries, and every element of an ultracapacitor is non-toxic.
The use of ultracapacitors in automotive power plants represents but one of many engineering advances in making the automobile, and by extension the automotive supply chain, more “green.”
From an engineering point of view, greening the automotive supply chain will require new products that will support more fuel-efficient power plants. Executives and engineers who embrace the promise of these devices will lead the way in developing environmentally sound, economically advantageous systems for the entire industry.
Chad Hall is the COO of Ioxus Inc., a manufacturer of ultracapacitors. Previously, he spent 14 years with Ioxus’ parent company, Custom Electronics Inc.