EET
2012 Energy efficiency roundtable

2012 Energy efficiency roundtable

Industry experts share insights on the latest trends in energy-efficient components and what to expect coming down the pike.

The quest for products able to meet standards such as Energy Star has electronic component makers scrambling to come up with offerings that excel in efficiency. To see how these efforts are progressing, we asked several industry leaders to share their observations, as well as their opinions on where the industry is heading. Their answers may surprise you.

What improvements in energy efficiency have you seen over the past year for your component category?

Keong • Avago: To improve efficiency and minimize copper losses, applications in the power area that use optocouplers are going to higher voltages instead of higher current. The trend among optocouplers is similar — they are providing higher insulation voltages, creepage, and clearance. The structure and packaging of these devices favors this trend, as it can support wide distance through insulation to withstand high voltages and thus protect systems and users. In fact, optocouplers are the only type of isolation device certified to the IEC 60747-5-5 standard for reinforced insulation, as compared to other types of non-optical monolithic isolators.

Armstrong • Linear: One of the most notable trends in energy management involves alternative energy. Plenty of ambient energy is available in the world around us and the conventional approach to harvesting involves solar panels and wind generators. However, new tools let us produce electrical energy from a wide variety of ambient sources. Further, it is not the energy conversion efficiency of the circuits that is important, but the amount of “average harvested energy” that is available to power it.

For example, thermoelectric generators convert heat to electricity, piezo elements convert mechanical vibration, photovoltaics convert sunlight, and galvanics convert energy from moisture. This makes it possible to power remote sensors or to charge a storage device such as a capacitor or thin-film battery, so a remotely located microprocessor or transmitter can be powered without a local power source.

Brown • Microchip: Environmental concerns and new legislation that forces energy efficiency have both challenged the lighting industry to replace the incandescent light bulb with more efficient technology. The most promising designs are those based on fluorescent/CFL and LED lamps. Unlike incandescents, LED lamps require some form of electronic drive.

Though still in its relative infancy, the solid-state lighting market is finally expanding beyond simply chasing the incandescent-bulb-replacement business. It is now moving toward intelligent lighting environments, enabled by microcontroller-based designs. By using a microcontroller, engineers can build-in numerous enhancements that allow for a smart lighting infrastructure that is efficient, costs less, and provides a better user experience. Microcontrollers also make it possible to design lighting functions that are more flexible than those available through pure analog or ASIC implementations.

Caroff • Siemens: Motor performance is always important to end users, but NEMA standard MG 1 defines this parameter, while efficiency has been dictated by the federal government since the inception of EPAct in 1992. The trend toward higher energy efficiency in motors will continue and we expect an update to motor efficiency standards from the federal level to become law within two to three years.

Spaziani • IR: One of our high-growth areas involves servers, with a focus on data centers. The two main reasons why data centers in particular must focus on energy efficiency involve total cost of ownership and room for growth. Electricity costs have risen substantially over the last several years. The cost of electricity for a single server not only includes server power consumption, but also the additional cost to provide the server power supply unit, distribution losses throughout the rack and building, and the cost of cooling the equipment.

Reducing energy dissipation on the server motherboard minimizes cooling costs and cuts the amount of power that must be distributed. For every watt saved on the motherboard, 2.5 W or more are saved overall.

A data center is often a single building or set of buildings with a limited and costly power infrastructure. The growth in cloud computing has resulted in server rooms filled to the point of no more power to be had at the rack, in the room, or in the building. What can you do if the data center needs more servers? The answer is to increase the computing power per watt, i.e., replacing inefficient servers with units that are more efficient and use less power. The alternative is to construct a new building or replace the entire power distribution center and cooling system.

How are new products meeting or leading the trends you’ve mentioned?

Keong • Avago: The latest 5 and 10 MBd digital optocouplers require low input driving current and low output supply power. These new devices have CMOS outputs, which can address needs for lower power, higher isolation voltage, and different packaging requirements.

A new generation of gate-drive optocouplers will have rail-to-rail output voltage, higher output driving current, faster speed, and will consume less power than the older generation. These are critical features which provide fast and accurate switching of IGBT or power MOSFET switches and will help motor controls and renewable energy inverter applications become more efficient.

Norton • TDK-Lambda: We’ve invested in developing more efficient power supply topologies, including digital control for ac-dc power supplies. We will continue to reduce power losses, particularly at low loads and during standby, by using digital control.

Armstrong • Linear: In general, the IC performance qualities this market looks for include low standby quiescent currents, typically less than 6 µA and as low as 450 nA; start-up voltages as low as 20 mV; high input voltage capability, up to 34 V continuous and 40 V transients; ability to handle ac inputs; multiple output capability and autonomous system power management; auto-polarity operation; maximum power point control (MPPC) for solar inputs; ability to harvest energy from as little as 1°C temperature delta; and a compact footprint with minimal external components.

Brown • Microchip: Commercial/industrial consumers account for more than half of all lighting sockets, and they tend to recognize more readily than residential consumers that higher up-front costs can be offset by medium-to-long-term energy savings and reduced maintenance costs. Features such as predictive failure and maintenance, light harvesting (ambient light compensation), remote communications and control, and occupancy recognition are just some of the advanced capabilities that can make intelligent lighting attractive.

Caroff • Siemens: A good example of a product designed for energy efficiency standards is the Siemens three-phase induction motors featuring die-cast copper rotors. These motors offer efficiencies one to three bands higher than the EISA government-mandated efficiencies and are available from 1 to 20 hp.

Spaziani • IR: One challenge is to reduce power losses for every voltage converter on a motherboard. We take a three-fold approach, focusing on MOSFET efficiency, packaging, and digital control. Servers are primarily 12-V systems and, as such, can utilize MOSFETS in switching dc/dc converters that are rated at 25 V maximum.

Servers often have two to four CPUs, four to eight memory banks, and upwards of 20 individual dc/dc POL converters on every motherboard. They take up a significant amount of space and need to continually become more efficient. By co-packaging MOSFETs with ICs for control or gate drive and utilizing copper clips to connect the high current paths, we’ve reduced parasitic losses in the packaging to effectively zero. This improves efficiency, reduces heat, and shrinks size.

What is the Holy Grail of energy efficiency for your component designs?

Keong • Avago: We’re working on new packages for systems to be able to sustain even higher working voltage for higher power with less loss. The challenge is to provide this high voltage insulation in an even more compact and slim form factor. Operation at a lower supply voltage and improved power efficiency will continue to be requirements for optocouplers.

Kerns • Siemens: The Holy Grail is developing the tools and means for any organization to understand, implement, and realize their energy savings potential.

Norton • TDK-Lambda: Besides the energy cost savings, a by-product of improved efficiency is that we can offer convection-cooling ratings, something that our customers have been requesting.

Armstrong • Linear: The Holy Grail would be for 100% energy conversion from the ambient energy source to the downstream system electronics. While this is not realizable, we do have products that convert more than 95%.

Brown • Microchip: Forward-looking lighting products will become completely autonomous with the ability to self-regulate light output relative to exterior light sources, self-regulate power consumption with a predetermined budget, self adjust color and brightness, and network into existing Ethernet networks.

Spaziani • IR: The Holy Grail is zero losses in dc/dc conversion at 10 MHz or more to significantly reduce size, while implementing fully digital operation with full telemetry on a high-speed serial bus. Customers expect better MOSFET and IC technology to continually reduce semiconductor losses.

However, it’s not yet possible to create MOSFETs in a monolithic solution that are as efficient as best-in-class discrete devices. Power management on a server is also extremely important, but customers continually want to either shrink size, add more memory or implement other features, and they want the power circuitry to take less space. Rising frequencies demand state-of-the-art MOSFETs, drivers, PWM controllers, or GaN devices.

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