Silicon Carbide (SiC) offers semiconductor technology with the capacity to meet all of new efficiency standards for size, weight, and power requirements without unviable trade-offs.
The October 2021 statistics from the International Energy Agency (IEA), which comprises 30 member countries and eight country associations, reaffirm the push toward increasing efficiency in energy consumption. While national budgets for energy efficiency and renewables have continued to grow, the IEA notes that the share of the budgets dedicated to energy efficiency has jumped from 7% in 1990 to 26% in 2020.1
New power plants cost over $500 million and two to six years to build, and the approximately 7% CAGR of the home appliance market outpaces the ability to bring new energy production online. Policymaking has therefore come to be dominated by discussions on the efficient use of global resources.
In the Americas, ENERGY STAR® and 80 PLUS® standards are driving engineering and consumer behavior. The ENERGY STAR program specifically is expanding its requirements to include home and commercial electric-vehicle (EV) chargers.
In Europe, the Middle East, and Africa (EMEA) region, the urgency to reach Paris Agreement goals of keeping global temperature rise below 2°C in this century has shifted focus on efficiency improvements in heating, ventilation, and air conditioning (HVAC) systems.
Greater China & Southeast Asia (GCSEA) is also emphasizing consumer appliance efficiency with new labeling and minimum energy-efficiency performance standards. For instance, on July 1, 2020, China implemented one of the world’s most stringent energy-efficiency requirements for room air conditioners by requiring them to be about 15% more efficient. Because the country is the largest buyer and manufacturer of these appliances, this could result in significant energy and carbon-footprint reduction.
Efficiency needs met by Wolfspeed Silicon Carbide
The direct impact of new efficiency standards is the undisputed need for Silicon Carbide (SiC) as the enabling semiconductor technology that has the capacity to meet all of the size, weight, and power requirements without unviable trade-offs.
Figure 1: Wolfspeed®’s portfolio includes products to meet the entire spectrum of power scaling.
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With the largest market share in SiC technology, over 30 years of power innovation, and more than 17 years of diode and MOSFET production, Wolfspeed helps designers meet standards requirements in key applications, including motors and switch-mode power supplies (SMPS), that find use across many industries as well as in some of the fastest-growing segments, such as EV charging infrastructure. The company’s SiC devices far outperform conventional silicon (Si) components and set new standards for efficiency and reliability.
Ready for IEC motor efficiency standards
The single-largest end use of electricity is by electric motor-driven systems (EMDS) in home appliances, industrial systems, and, increasingly, EVs. An estimated 43% to 46% of global electricity consumption and 6,040 megatons (Mt) of CO2 emissions were from running EMDS in 2009. Without policy and standards support, EMDS could consume 13,360 TWh and result in 8,570 Mt of CO2 emissions annually by 2030.2
The global IEC/EN 60034-30-1 standard addresses efficiency in this application area. Defining International Efficiency 1 (IE1) through IE4 efficiency classes with an upcoming IE5 class, the standard expanded its scope in 2014 to cover two-, four-, six- and eight-pole motors rated 120 W to 1,000 kW at 50-V to 1-kV input.
Most countries either already require or will soon require a minimum rating of IE3, with EMEA demanding IE4 in July 2023 for motors in the 75- to 200-kW range. Transitioning from IE2 to IE3 for a 2.2-kW four-pole motor means increasing efficiency from 84.3% to 86.7%, for a 15.2% reduction in losses. An IE3-to-IE4 transition requires a 21% reduction in losses as the total efficiency increases to 89.5%. Such transitions will require redesigning systems, which is made easier by moving from Si to SiC.
For EVs, which use 90-kW to over 350-kW EV drivetrain inverters, increasing efficiency and decreasing size and weight translate to maximizing vehicle range. Wolfspeed SiC-based designs ease bidirectional designs to enable regenerative braking, lower losses by 80%, and decrease size by 30% while lowering system cost, as is evident from the real-world drive in Figure 2.
Figure 2: The Silicon Carbide inverter losses are well below those in Si-based systems (graph). Cost savings from space and cooling reductions are in addition to those listed above and vary by vehicle model.
New standards for Switch Mode Power Supply (SMPS) efficiency
SMPS are widely used in commercial, industrial, home appliance, energy, and EV segments. Just one application, the data center, is estimated to have consumed about 205 TWh in 20183 — or 1% of global electricity use.
ENERGY STAR efficiency requirements are surpassed by the 80 PLUS program’s Platinum and Titanium certification requirements as well as EU’s Ecodesign in Europe (ErP) Lot 9 regulations, which have an even more stringent update scheduled for January 2026. The Open Compute Project’s (OCP’s) ORV3 PSU specifications require 40% fewer losses than the ORV2 and 80 PLUS Titanium (Figure 3).
Figure 3: New standards require >98.55% efficiency from the PFC and >97.12% from the DC/DC stage.
These standards place new demands on power supply design and require designers to carefully assess the topologies they use. Whereas a SiC-based, semi-bridgeless totem-pole Power Factor Correction (PFC) with Si diodes in the low-frequency leg could deliver 98.9% efficiency for the latest 80 PLUS standards, ORV3 shifts preference to an all-SiC–MOSFET bridgeless totem-pole PFC to deliver 99.1% efficiency.
Wolfspeed’s C3M™ 650 V SiC MOSFETs are particularly well-suited to this application. Its 2.2-kW PFC reference design achieves 80 PLUS Titanium standard with >98.5% efficiency and THD <5% in industrial, EV charger, and server/telecom PSU applications.
ENERGY STAR® certifies EV chargers
The U.S. government has approved $5 billion over the next five years to build an infrastructure of 500,000 DC fast chargers each capable of delivering a minimum of 150 kW per port and simultaneously charging four EVs. Meanwhile, the ENERGY STAR specification for Electric Vehicle Supply Equipment (EVSE) took effect on March 31, 2021, mandating a minimum active charging efficiency of 93% for up to 65-kW chargers and bringing DC fast chargers up to 350 kW under its scope.4 Certified EV chargers generally require about 40% less energy on standby mode.
Figure 4: Wolfspeed® Silicon Carbide reduces losses by 42% with 51% greater power density at lower system costs in this full-system 22-kW bidirectional DC fast-charger comparison of Si versus Silicon Carbide.
Commercial and home users alike look for ENERGY STAR certifications, and Wolfspeed’s MOSFETs and diodes enable 1% to 2% higher efficiency, 35% to 50% increase in power density at comparable system costs, less overall system cooling, smaller and cheaper mechanical housing, and better bidirectional charging for vehicle-to-grid than possible with Si-based designs (Figure 4).
Portfolio for energy efficiency
To meet an incomparable breadth of design considerations, Wolfspeed delivers an equally wide Silicon Carbide portfolio comprising products that scale from 600 V through 1700 V with 3.3 kV and above in development, and from 1 A to nearly 1 kA in power modules. Whatever the power application, there is a Wolfspeed Silicon Carbide discrete product, smaller baseplate-less module built to industry standards, or an optimized-footprint high-power module that not only helps designers meet the latest standards but plan for upcoming requirements in their development roadmaps.
Sources:
- IEA, Energy Technology RD&D Budgets: Trends across technologies, October 2021. https://www.iea.org/reports/energy-technology-rdd-budgets-overview/trends-across-technologies
- IEA, Energy Efficiency Policy Opportunities for Electric Motor-Driven Systems. https://www.iea.org/reports/energy-efficiency-policy-opportunities-for-electric-motor-driven-systems
- Energy Innovation, et al, How Much Energy Do Datacenters Really Use?, March 17, 2020. https://energyinnovation.org/2020/03/17/how-much-energy-do-data-centers-really-use/
- ENERGY STAR Version 1.1 EVSE Certification Webinar Slides - April 8, 2021. https://www.energystar.gov/sites/default/files/ENERGY%20STAR%20Version%201.1%20EVSE%20Certification%20Webinar_4.8.21.pdf
- ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 80 PLUS® is a registered trademark of Clearesult Consulting Inc.