BPEI Pioneers Study of Semiconductor Efficiency

The Biophysical Economics Institute (BPEI) and Wolfspeed recently collaborated on a pioneering study that demonstrates the superior performance of silicon carbide vs. traditional silicon semiconductor devices in electric cars. When silicon carbide is used in the powertrain of an electric vehicle, it delivers a 13:1 energy savings vs. the incremental energy invested, as compared to traditional silicon chips. This significant energy conservation allows for longer range, lighter weight and faster charging – all of which foster lower long-term energy usage and enhanced environmental sustainability.

The study uses BPEI’s proprietary Energy Saved on Energy Invested (ESOI) metric, which allows for an apples-to-apples comparison of energy efficiency across applications and industries, taking into account the long lifespan of many advanced technologies. Our analysis calculates the energy saved over an equipment’s life cycle, relative to the incremental energy used in its production – with silicon carbide as a key use case.

ESOI, a concept based in the natural sciences, offers corporations, industry organizations and non-profit groups an objective standard, based on measurable energy and material flows, for evaluating the energy efficiency of any technology.

“These methods represent a reliable, rigorous metric to quantify environmental, social and governance benefits,” said Dr. Charlie Hall, BPEI Board member and co-chair of the Institute’s Advisory Board. “ESOI-anchored decision making allows us to maximize the potential of our precious natural resources, paving the way for a more effective energy transition.”

Key findings of the Wolfspeed study include:

  • Replacing silicon insulated-gate bipolar transistors (IGBTs) with Silicon Carbide metal-oxide semiconductor field effect transistors (MOSFETs) produces substantial energy savings for electric vehicles
  • The lifetime energy savings from employing silicon carbide MOSFETs are many times the incremental energy required to produce these devices
  • The ESOI for 400V vehicles is approximately 7:1 vs. a typical EV sedan (400V silicon carbide MOSFET vs. 400V silicon IGBT)
  • The ESOI of an 800V silicon carbide semiconductor in an EV sedan is 13:1 (800V silicon carbide MOSFET vs. 400V silicon IGBT) – an 85% increase vs. the 400V silicon carbide MOSFET, due to reduced chip surface area and the corresponding energy invested
  • The ESOI gain is greater for fleet vehicles, such as taxis and delivery vans with higher duty cycles

BPEI’s analysis underscores the potential for large fuel savings based on intelligent location of manufacturing hubs close to natural energy sources.

“A growing number of Wolfspeed customers are in the automotive industry, and we believe the next generation in power semiconductor technology will be driven by silicon carbide,” said John Palmour, chief technology officer at Wolfspeed. “This study with BPEI reinforces the superiority of silicon carbide. As the world shifts to a more sustainable future, it will need efficient materials to power it.