“Well to Wheel”: new index for car development. Intensifying companies’ approach toward carbon-neutral society.

How many kilometers can a car run on a liter of gasoline? ――

This index, called “Tank to Wheel”, shows fuel efficiencies of cars. Manufacturers commonly used this index of how much distance their cars can run on a specific amount of fossil fuel when they competed technologically. Now, the situation is changing. Due to global warming, companies have been confronted with the necessity for CO₂ emissions reduction. This is also true in the automaker industry, where manufacturers are required to shift into developing carbon-free products called “zero-emission vehicles”.

Now, the EU is the focal point of electric vehicles (EVs) promotion. But replacing even all vehicles with zero-emission ones worldwide does not mean the automobile industry will be completely carbon-free. The reasons for this include most of the electricity used to charge EVs is generated by converting heat energy of fossil fuels, and power grid maintenance and car manufacturing processes also require a lot of resources and labor, emitting CO₂.

Recently, a new index called “Well to Wheel” has been in the spotlight to assess energy efficiency more comprehensively. This index covers a wider scope ranging from fuel production (gasoline, electricity, etc.) to car driving, meaning how and where energy is consumed and converted and CO₂ is emitted through the chain from fuel production at oil wells, refinery processes, fuel transportation, to a car’s wheel rotation.

At this moment, total zero-CO₂ emissions is considered difficult. Instead, many nations have shifted to the “carbon neutrality” concept, where a state of net-zero CO₂ emissions (neutral) can be achieved by balancing out the amount of emitted CO₂ by the amount of CO₂ absorbed or removed. Now, 124 nations including Japan have committed to achieve carbon neutrality by 2050. The role of the automaker industry will be significant in promoting it.

Toward “Well to Wheel zero-emission” mobility, some automakers seek to promote collaboration with other industries by integrating their technologies and solutions into their own car development to reduce CO₂ emissions.

An Australian startup, Applied EV, which is aiming to develop lighter low-speed electric vehicles (LS-EV), has made a prototype with a maximum speed of up to 70 km/h. Teijin has offered its advanced technologies and expertise such as light-weight, high-strength materials and processing and molding technologies. For example, Teijin’s Glass Fiber-Sheet Molding Compound (GF-SMC), a light-weight, high-strength, high-stiffness material, is used for the prototype’s platform to achieve low-energy driving and optimal energy efficiency.

Teijin’s Panlite, a light-weight, impact-resistant, infrared-ray-screening polycarbonate resin, is used as the glazing for the windows and doors to reduce the effects on the inside temperature. Teijin’s nonwoven polyester fabric with vertically oriented fibers is used as the heat-insulation material. Panlite glazing is also used on the prototype’s roof, which is covered with PV panels for charging the prototype. In a test in Australia, the panels recorded about 330 W output, equivalent to that of common roof-top PV panels.

“Well to Wheel” will draw more attention as a keyword to realize a sustainable circular society. EVs are one of the trump cards for achieving carbon neutrality and it is apparent that companies’ efforts to realize and enhance technical platforms regarding EV development will be more intense.