| Advanced energy storage technologies offer new back-up power options
The report’s highlights are: * Research and development of advanced energy storage technologies is driven by the demand for high quality electricity that is increasing worldwide at every level of application. Starting with small portable devices, to mid-level applications for hybrid/electric vehicles (HEVs) and remote power security, to utility support for uninterruptible power supply (UPS) and power quality management; Frost & Sullivan estimates that the UPS market alone will reach $6.75 billion by 2008. * Although more than 80 percent of power line disturbances last less than a second, that is long enough to create havoc with high-tech industrial equipment, which is extremely sensitive to power disturbances. * The Electric Power Research Institute (EPRI) estimates that electric power disturbances cost US businesses between $119 and $188 billion each year. The problems at the grid level are exacerbated by an aging generation mix and transmission network. Add to all that, EPRI estimates that electric power as a percentage of the total energy use in the United States has reached 40 percent, and will increase to 50 percent by 2020. * According to EPRI, 50 percent of the UPS market uses traditional batteries, which is vented (also called flooded) lead-acid batteries. The other 50 percent comprise transient voltage suppressors and other technologies such as diesel generators. * Although lead-acid batteries have been the workhorse of energy storage for vehicles and mid-level applications for well over one hundred years, the lead-acid battery of today is a far better energy storage technology. Competition for the traditional configuration lead-acid batteries are valve regulated lead-acid (VRLA) batteries, which were first introduced in the 1970s. * Other competitors for UPS applications include flywheel technologies, fuel cells and superconducting magnetic energy storage (SMES) batteries. However, the world’s most powerful storage battery system has nickel-cadmium batteries that are capable of producing up to 46 MW for a short time. The award-winning battery energy storage system (BESS), weighing in at 1300 tons, was installed to provide spinning reserve for the Golden Valley Electric Association (GVEA) in Fairbanks, Alaska. * Although the majority of the advanced energy storage technologies are based on electrochemical sources, there are a number of technologies that have other storage mechanisms. Flywheels store kinetic energy. Like lead-acid batteries they serve markets that range from mid-size to large. Also like lead-acid batteries they are an old technology that has an all new look. Flywheels have been long used to smooth the ride in the transportation market and for integrated power and attitude control systems applications in space. * In the UPS market, flywheels coupled with gensets can provide continuous power systems for longer-term outages - minutes to hours to days. Flywheels in use today contain high-tech composite wheels and operate at ultra-high rotational speeds. An experimental composite flywheel developed at the University of Texas set a record by spinning at 3,000 mph. * Another technology that is not based on an electrochemical reaction is the ultracapacitor, otherwise known as supercapacitor. The technology also has roots in much earlier times, but early capacitors have a resemblance only in principle to today’s devices. Ultracapacitors store electrostatic energy. In many applications they work with other energy storage devices. Batteries store a lot of energy but discharge power at a low level; ultracapacitors store energy and release it in pulses of high power.
•Date: 10th August 2004 • Region: Worldwide •Type: Article •Topic: Power management Rate this article or make a comment - click here |
