Power Electronics

Part Two: The Electric Grid—Now and in the Future

Last month, I pondered the magnitude of the electrical grid, its availability (uptime), implementation cost and some common methods that increase availability to users (read: Part One: The Electric Grid—Now and in the Future). Now I’d like to consider the possible impact of recent trends on the grid and speculate as to where the electrical grid may be headed in the future.

Like the Blob from the sci-fi movies of the 1950s, the electrical grid is a living, breathing ever-expanding system. It not only extends its tentacles to all reaches of the system, but morphs into other forms as power requirements change. Those transformations of power at the edge of the grid can, in turn, influence how power flows both from and back to the grid.

For example, in many applications there’s a trend toward high reliability and uptime. This requirement has lead to the addition of energy generators and storage tanks at the extremities of the grid’s tentacles. Although these sources spring into action whenever there is a shortage or disruption of service, most of the time they sit idle. But it is feasible that backup storage and generation capabilities could be used to feed the grid during peaks in energy demand — either now or in the future. By monitoring such energy returns to the grid, the system could provide revenue to users.

Alternative energy sources already return power to the grid, helping to alleviate the burden on conventional energy sources. Turbines, windmills, solar farms and sea-wave energy generators are just a few such alternative energy systems that can augment the oil, coal, water and nuclear powered generating plants.

Another trend is that devices are breaking away from the power grid’s tentacles. Appliances like The Rumba Vacuum cleaner have broken the electrical leash, returning to the charging station only when the hunger for additional power becomes overwhelming. Plug-in hybrid electric vehicles (PHEVs), which are presently on the drawing boards, could become another example.

When they become available, PHEVs will sit in the garage over night and suck up the juice. Because these vehicles will still have a gas tank, they’ll be capable of longer driving excursions than a pure electric vehicle. And because they’ll be capable of holding large amounts of energy, their batteries may one day be used to deliver backup power to the grid during peak power requirements.

This use will be possible if PHEV owners can leave their parked vehicles plugged in during the daytime. Returning some of their energy back to the grid — when energy rates are highest — may earn vehicle owners some income that offsets the cost of charging their vehicles.

Still another trend concerns some very large consumers of power, who are moving their facilities to locations with access to cheap power. In the web infrastructure, power delivery to server farms and data centers is now a bottleneck, and electricity costs heavily impact operating costs. Consequently, companies like Google, Microsoft and Yahoo are flocking to areas with cheap power like bees to honey.

According to recent Dutch newspaper reports, a massive new server farm capable of holding 100,000 servers is being built in the Eemshaven (Eems Harbor). This farm will have access to 30 MW of power, mostly coming from a huge power plant that is just a stone’s throw away.

Google is currently building a data center server farm on the Columbia River (approximately 80 miles from Portland), where it’ll be near a hydroelectric power source. This server farm consists of a supercomputer with more than 6000 processors and is approximately the size of two football fields. Google is also planning to build a big data center in North Carolina for pretty much the same reasons: accessibility and low cost of power.

Yahoo and Microsoft are not far behind. They are spending billions in the Pacific Northwest to build out their web infrastructure. Microsoft recently broke ground on a 1.4-million-sq-ft campus in Quincy, Wash., close to hydroelectric power.

"If I saved just $10 in the operation of each of those servers, that's $10 million per year," says Greg Papadopolous, CTO of Sun Microsystems, in a recent Fortune magazine interview. "So, how much would you be willing to invest in order to save $10 per server?”

Up until now, power-supply designers concentrated mainly on designing devices that convert higher ac voltages to stable low dc voltages. Such devices perform these tasks at ever-increasing efficiencies and are capable of intelligently communicating with each other to provide higher-reliability power conversion. But based on the recent developments in grid usage, future designs will provide the added design challenges of converting low dc voltages to the high ac voltages required to feed the grid. And due to the complexity and multitude of remote locations, they will have to do so very intelligently.

With the Internet, datacom and telecom stoking the fires of the electric grid, the need for ever-increasing uptime, local power generation and the untethering of various applications from the grid, those working in power electronics are in for a wild ride into the future. Are you ready to meet the challenge? Send your comments to me at [email protected].

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