UC Davis Study Concludes That the Ongoing Rapid Growth of Electric Two-Wheelers in China Could Drive Further Electrification of Transport Sector

11 May 2008

Motorized vehicle sales in China. Click to enlarge. Source: J. Weinert et. al. (2008)

The market for electric two-wheelers (E2Ws) in China is booming; by 2006, the annual sales of E2Ws—which were virtually non-existent in the 1990s—almost equaled those of gasoline two-wheelers (G2W) (see chart at right). A new report from a team at the UC Davis Institute of Transportation Studies analyzes the E2W phenomenon.

The authors—Jonathan Weinert, Joan Ogden, Dan Sperling, and Andrew Burke—conclude that the balance of forces driving and resisting E2W growth appears to favor ongoing E2W growth. This growth in turn will likely drive further vehicle electrification through continued innovation in batteries and motors, the switch from lead-acid to Li-ion batteries in E2Ws, and the development of larger E2Ws and EVs.

As a category, E2Ws in China range from two-wheel electric bikes that use an electric motor to supplement human pedaling to low-speed scooters propelled almost entirely by electricity, with a spectrum of styles in between. In most cities, E2Ws are allowed to operate in the bicycle lane and are considered a bicycle from a regulatory perspective (i.e. helmets and drivers licenses are not required).

The ITS authors used force field analysis (FFA) to assess the set of forces influencing future E2W growth in China and the relationships between these forces. FFA creates a descriptive model of a complex system that intersects many disciplines (technical, social, political, etc.). The analysis in the study has five steps: identify the system of focus and boundaries; generate list of driving and restraining factors; determine the inter-relatedness of these factors; quantify the forces; and chart the force field diagram.

Through this analysis, we conclude improvement in E2Ws and battery technology is a driving force that can be partially attributed to the open-modular industry structure of suppliers and assemblers. This type of structure was made possible by the highly modular product architecture of E2Ws, which resulted in product standardization and enhanced competition amongst battery technologies.

In an open-modular (O-M) industry, manufacturers act primarily as assemblers and source components produced by a large decentralized network of suppliers. This type of structure is typically found when a product exhibits high modularity, the authors note, meaning it can be divided into several modules that are copied, mass-produced, standardized, and easily bought on the market. This type of structure is also found in the modern computer industry and several other Chinese manufacturing industries.

Growing air quality and traffic problems in cities in part due to rapid urbanization has led to strong political support for E2Ws at the local level in the form of motorcycle bans, and loose enforcement of E2W standards. There are softer signs of national support for this mode in part due to national energy efficiency goals. Public transit systems in cities have become strained from the effects of urbanization and motorization, which has stimulated greater demand for “low-end” private transport.

However, the authors note, there are formidable forces resisting E2W market growth. These include:

• The superior performance of motorcycles;

• Bans on E2Ws, influenced by the spread of automobile use and the loose enforcement of E2W standards resulting in low-quality E2Ws on the market;

• City policies of promoting public transit, along with investment in transit infrastructure.

Based on results of the FFA, we conclude that driving forces appear to outweigh the resisting forces for E2Ws. This may lead to accelerated adoption of EV. Growth in the EV market is dependent on continued improvement in battery cost and performance and the development of larger E2Ws vehicles. Two trends in the E2W industry may facilitate this development, namely its open modular industry structure and modular product design.

However, there are some major obstacles facing EVs that will not be easy to overcome in China. The largest is the issue of recharging infrastructure, which will need to be built since EV batteries are not portable like E2W batteries.

Other obstacles include battery cost and inherent complications with large battery systems.

...A shift from gasoline-powered vehicles to EVs in Chinese cities, like the shift from G2Ws to E2Ws in recent years, would have several concrete benefits including local air quality improvement and reduced dependence on imported petroleum. However, because of the high carbon intensity of grid electricity caused by heavy reliance on coal power, a shift to EVs could result in a net increase in CO₂ emissions. Furthermore, if future EVs use lead batteries, lead contamination of soil and water could be exacerbated.

To maximize the benefits of electric drive transport, the authors suggest that policy makers in China takes steps to lower the carbon intensity of the grid and to encourage a transition to advanced batteries.

Resources

• Weinert, Jonathan X., Joan M. Ogden, Daniel Sperling, Andrew F. Burke (2008) The future of electric two-wheelers and electric vehicles in China. Energy Policy In Press