Wide bandgap materials such as silicon carbide and gallium nitride are the best options to meet the growing battery demands of electric vehicles, and silicon carbide is expected to displace silicon in EVs by 2020, according to Lux Research.
Economics are in favor of wide bandgap materials. For a Tesla Model S, a 20 percent power savings would mean a gain of over $6,000 in battery cost, or 8 percent of the car’s cost. Batteries are a big concern for the carmaker, which signed an agreement with Panasonic last month to build a 10-million-square-foot facility for battery production.
According to Lux analyst Pallavi Madakasira, having efficient power electronics is essential for smaller battery size, which impacts the car’s wiring, thermal management and weight. The addition of consumer applications such as infotainment and screens will double the number of power components built into each car as well.
Observations regarding system-level benefits that wide bandgap materials bring to the automotive industry include the following:
- Lower power saving thresholds. At 2 percent power savings, if battery costs fall below $250/kWh, silicon carbide diodes will be the only economic solution in EVs requiring a large battery. However, the threshold power savings for plug-in EVs will need to be 5 percent.
- Race to market. Silicon carbide diodes are ahead of gallium nitride in technology readiness and will make it to market earlier, based on the current technology readiness level. Based on the technology readiness level road map, silicon carbide diodes will be adopted in vehicles by 2020.
- Government funding. The US, Japan and the United Kingdom, among others, are funding research and development in power electronics. The US Department of Energy is spending $69 million this year and defining performance and cost targets. The Japanese government is funding a joint industry and university research and development program that includes Toyota, Honda and Nissan.
Last month, a study by Northeast Group revealed that 25 electric utilities across 14 states are now offering electric vehicles rates and tariffs as part of an effort to engage the growing number of customers who drive electric vehicles.