FOR THE average computer or network, the only thing worse than the electricity going out completely is the power going out for a second. Every year, millions of dollars are lost to seemingly insignificant power faults that cause assembly lines to freeze, computers to crash and networks to collapse. The Electric Power Research Institute, an industry research and standards group based in Palo Alto, California, estimates that 80% of the power glitches that wreak havoc on an electronic system last for less than a few seconds—barely noticeable to the eye. In light of events such as the California power debacle, many expect the rate of those disturbances to rise, as deregulation and distributed generation place ever more stress on America's ageing power grid.
That expectation has fuelled a boom in “power-cleaning” technology, driven by innovations that promise to deliver near-faultless power to the digital economy. Some of the developments that are nearing adoption include power-chips that can switch from the electrical grid to alternate power sources in milliseconds; flywheels and super-capacitors that allow equipment to ride through a power hiccup; and silicon power plants capable of delivering megawatts of extremely “clean” electrical power. The result, says Mark Mills of the Huber-Mills Digital Power Report, will be a $500 billion industry rising from America's tangled power lines.
For more than a century, the reliability of the electricity grid has rested at 99.9%—“three nines” in industry jargon. That permits about eight hours of outages a year. When the economy was built around incandescent bulbs and electric motors, three nines was more than enough to keep the wheels of industry turning. But microprocessor-based controls and computer networks demand at least 99.9999% reliability, or “six nines”, amounting to no more than a few seconds of allowable outages a year. And that is just a start. The report estimates that the quality of electrical power must reach “nine nines”—milliseconds of faults a year—before the digital economy can truly have the right quality power to mature.
Over the years, various pieces of back-up equipment have filled in during outages, but most of the technologies available today barely deliver the quality needed. Hospitals, phone companies and military bases deploy banks of generators to ensure that their operations stay up and running for 99.99% of the time. But that still amounts to minutes of outages a year. Similarly, most high-tech companies have generators to supplement their power needs, but they also add “uninterruptable power sources” that use batteries to power computers until the generators kick in. Each solution, however, introduces its own problems. Generators do not react fast enough and can deliver dirty power of their own. Meanwhile, batteries are expensive to maintain and may not react fast enough.
Innovations in electrical-power handling promise to improve matters considerably. At the centre are power-chips, first developed in the early 1980s but only now reaching their full potential. Power-chips based on metal oxide semiconductor field-effect transistors (MOSFETS) and integrated bipolar transistors are produced by such firms as International Rectifier of El Segundo, California, IXYS of Santa Clara, California, and Advanced Power Products of Portland, Oregon. They work by splitting a stream of electrical power into tiny packets that can be reconditioned into a more appropriate form. Power-chips can also switch between grid and stored power in milliseconds to ensure uninterrupted power.
Until recently, however, such chips could only switch small amounts of power at high resistance and low efficiency, relegating them to small, niche applications. Now they are capable of switching at much higher voltages and currents in ever shorter times. More to the point, it is only recently that users have learned how to exploit them properly in order to solve their problems. International Rectifier, which holds many of the patents for MOSFET power-chips, expects the devices to penetrate all electrical equipment—from computers to electric motors and even light bulbs—yielding significant efficiency gains in addition to delivering cleaner, more reliable power.
Coupled with the new power-chips are power-storage innovations that deliver short bursts of power quickly. Among the most promising of these are flywheel systems, which store energy in rotating discs that connect to generators whenever the power is interrupted. Flywheels take up a fraction of the space of lead acid batteries and all but eliminate the latter's maintenance problems. New systems developed by companies such as Active Power of Austin, Texas, and Beacon Power of Woburn, Massachusetts, use composite and steel flywheels rotating at up to 20,000 revolutions per minute to deliver bursts of power that can last as long as 30 seconds.
Meanwhile, superconducting electromagnets made by firms such as American Superconductor of Westborough, Massachusetts, and ultra-capacitors from the likes of Maxwell Technologies of San Diego, California, can deliver bursts of power and be recharged quickly and without any degradation. When coupled with the new power-chips, these systems can switch hundreds of volts of electricity instantaneously, making them ideal for large manufacturing plants and even for sub-stations on the grid.
The acme of all that development is what Mr Mills calls the “silicon power plant”, developed by power equipment makers such as Emerson Electric of St Louis, Missouri. These plants deliver megawatts of “high-nine” electric power to computer- network centres that house critical servers and hubs for major corporations and telecom carriers.
Despite all the advances, however, some planners in the electrical power industry warn that there is a possibility of reliability-overkill. With each additional “nine” of reliability, costs can rise ten- to 100-fold. At “three nines” a kilowatt-hour costs about 10 cents. At “five nines”, it will cost $20 when investment is taken into account. At “six nines”, it could cost $1,000. Yet not all computer systems need such faultless reliability. Indeed, any company considering an investment in powercleaning should work out exactly how much a glitch would really cost its operations compared with the investment involved. The differences might be a powerful incentive for making do.