News

# Efficiency isn’t Enough

September 15, 2013 by Jeff Shepard

This week, PowerPulse will be running a series of exclusive stories as a wrap-up of last weekâ€™s Darnell’s Energy Summit (DES ’13), hosted in Richardson, Texas. The Keynote and Plenary speakers at DES ’13 all pointed in a common direction when discussing the future of the power electronics industry. Opening the Summit, Scott Barbour, Executive Vice President with Emerson and the Business Leader of Emerson Network Power (Systems) summed up that common theme when he observed, â€œefficiency isnâ€™t enough.â€

â€œWe demand all information on every device we own, everywhere we go. Fast. To accommodate, industries are not only demanding more power than ever, but they are seeking new levels of efficiency in the power chain and new, more environmentally responsible sources of generation. Once disparate industries from IT to telecommunications and content delivery are converging at record pace. Energy delivery and management, too, has become a melting pot,â€ Mr. Barbour continued.

â€œBoth ac and dc power are viable options in facilities of all types and are bringing new energy-saving possibilities to micro grids. And the intelligence to see and control that energy use doesn't stop at the outlet. Smart Grid innovations are magnifying the energy savings made possible by the visibility and control now possible within a building's walls. Effectively monitoring and managing energy has become the key. And there are large and growing opportunities in meaningful and timely analytics,â€ Barbour concluded.

Brian Patterson, Chairman of the EMerge Alliance and General Manager of Armstrong World Industries built on the themes started by Barbour and painted a picture of â€œThe EMerge Vision: Creating the Enernet.â€ Patterson described a future where advanced components and new architectures â€œdo for power what the Internet did for information networking.â€ He spent a few minutes describing the future use of HVDC in utility grids, but quickly drilled down to local dc micro grids as the key to the future Enernet.

â€œDC power will fundamentally change the way power is distributed in buildings,â€ according to Patterson. Combining integrated designs with on-site renewable energy (such as photovoltaic generation), local energy storage to enable grid independence and system intelligence to control and monitor energy generation and use on a local (micro grid) basis has the potential to move us to net zero energy buildings.

Patterson continued with the following description of the U.S. Depart of Energyâ€™s Zero Energy Commercial Buildings Consortiumâ€™s goals: Begin DC Microgrid Demonstrations in 2013. By 2030 all new commercial buildings will be zero energy users. By 2040 50% of all commercial building stock will be zero net energy structures. And by 2050 all commercial buildings in the U.S. will be zero net energy users.

The morning Plenary session was closed by Kurt Yeager, Vice Chairman of the Galvin Electricity Initiative and the Perfect Power Institute. As the former President of the Electric Power Research Institute, Mr. Yeager is especially well positioned to address his topic of, â€œDC Microgrids â€“ Challenges & Opportunities.â€ One of the chief goals identified by the efforts to develop dc microgrids is to â€œconvert buildings from Power Pigs into Power Plants,â€ according to Mr. Yeager.

He identified numerous specific benefits from the3 successful development and deployment of dc microgrids including: The ability to optimize distribution performance and service value and local optimization of dc power. Seamlessly integrating the supply of electricity and the demand for electricity. Providing the most user-friendly consumer empowerment for the use of electricity and local generation and storage. Opening the door to entrepreneurial innovation and enabling local green enterprise zones.

Yeager called dc microgrids, â€œâ€œThe ultimate example of energy democracy by diversifying supply infrastructure ownership.â€ He further identified over $1 trillion in annual benefits for the U.S. economy from the deployment of dc microgrids. And he claimed that the initial investment needed to realize those benefits is a relatively modest$25 billion.

Opening the afternoon Plenary session at Darnellâ€™s Energy Summit, Alex Lidow, CEO and co-founder of Efficient Power Conversion Corporation (EPC) his vision of, â€œGaN: Crushing Silicon One Application at a Time.â€ He pointed to wireless power transmission and envelope tracking in RF power systems as two of the key near-term applications for GaN power devices.

Then he provided delegates with a â€œsneak previewâ€ of the next-generation of GaN devices to be introduced by EPC. Called â€˜Gen 3â€™ these new devices will feature higher-frequency operation (1-3 GHz), higher-voltage capabilities (up to 600V) and more functions on a chip such as a monolithic half-bridge configuration including drivers on a single chip.

A highlight of Lidowâ€™s talk was the introduction the EPC2016 as the newest member of EPCâ€™s family of eGaNÂ® enhancement mode gallium nitride power transistors. The EPC2016 is a 3.36 mm-square, 100-VDS, 11A device with a maximum RDS(on) of 16 milliohms with 5V applied to the gate. This GaN power transistor delivers high performance due to its ultra-high switching frequency, extremely low RDS(on), exceptionally low QG (5.2 nC, maximum) and in a very small configuration.

Compared to a state-of-the-art silicon power MOSFET with similar on-resistance, the EPC2016 is much smaller and has many times superior switching performance. Applications that benefit from eGaN FET performance include high-speed dc-dc power supplies, point-of-load converters, class D audio amplifiers, and high frequency circuits.

â€œThe EPC2016 is an excellent complement to our existing family of eGaN FETs. The lower gate charge and output capacitances significantly reduce the switching losses in power conversion applications,â€ Lidow noted. Within a few years, not only will GaN devices outperform conventional silicon power switches, they will be lower in cost, driving silicon to the brink of extinction, according to Lidow.

Continuing the theme of advanced power conversion and power management technologies, Randy Malik, Senior Member Technical Staff and Distinguished Inventor with IBM talked about, â€œLeveraging Digital Power Management in Tomorrow's DC-Powered Data Centers .â€ As the first step toward the data center of the future, Malik described the energy consumption payoffs from the effective use of digital signal processors (DSPs) in digital power conversion and management.

Those benefits include: unity power factor implementation for 3-phase boost regulators, faster response for boost regulators, efficiency improvements, DSP is the most cost effective way to monitor, control and measure power, power consumption drastically reduced due to the implementation of complex algorithms which are possible by DSP usage. And reliability improvement due to the operating of the components at the least stressed conditions in real time operating conditions.

After pointing out the current benefits from the use of digital power, Malik gave the delegates to DES â€˜13 the challenge to design future data centers with a power usage effectiveness (PUE) of less than one! The lower the PUE, the better and todayâ€™s typical data center has a PUE of over 1.8. Today, an advanced datacenter may achieve a PUE of 1.33; enabled through the use of variable-speed drives for the cooling system, high-efficiency power converters, dc power distribution, and so on.

Replacing traditional cooling systems with water cooling reduces the need for air movement and the associated motor drives, improving the PUE up to 1.09, according to Malik. He then challenged the audience by stating that future datacenters would have integrated photovoltaic energy generation, lights-out operation, and other advanced design and operational techniques to produce PUEs of less than 0.75! A goal recently thought to be impossible.

The 2013 Darnellâ€™s Energy Summit was a combined event featuring the Tenth Darnell Power Forum (DPF '13) plus the Fifth Green Building Power Forum (GBPF '13) plus the Fourth Smart Grid Electronics Forum (SGEF '13). DES â€˜13 featured the next-generation of power electronic devices, architectures and systems. Each of the individual events maintained its unique identity and continued to serve different groups of stakeholders. These co-located events successfully brought together thought leaders across the areas of advanced power electronics, energy management, micro grids, the smart grid, and related topics of global importance. Planning has already begun for an even larger edition of Darnellâ€™s Energy Summit in 2014.