The time-honored discounted cash flow method for determining appropriate utility returns falls short when interest rates are low. Inadequate ROEs ultimately increase cost of capital and wipe away...
The Top 10 Utility Tech Challenges
Innovation must play a key role in each company.
rating (DTCR) systems, video-sag monitoring, and topology estimators. For example, DTCR uses real-time information about weather, load, temperature, line tension, or line sag to estimate actual thermal limits (rather than static limits based on worst-case weather conditions), thus allowing higher thermal capacity of transmission lines and substation equipment. This capability can be extended by monitoring the actual conductor sag in real time using sensors mounted on a transmission tower.
Challenge 2 Improve Power System Reliability and Address Power Quality
Two important motivations for upgrading the aging power delivery infrastructure are to improve power-system reliability and address the issue of power quality. Although the most visible recent motivation to improve system reliability may have been the Aug. 14, 2003, U.S./Canadian blackout, the hard fact is that the number of people affected by outages is rising (see Fig. 2, p. 49). Arresting this rise and mitigating wide-area blackouts will require technological advances in more than a few areas. Congestion on transmission lines can be mitigated by optimizing system-operating methods, increasing system capacity, managing aging system assets systematically, and planning for the long term. At the same time, efforts to increase the reliability of individual components can complement methods of increasing wide-area reliability via system control and protection.
Power electronics-based controllers—one of the most successful power-delivery technologies developed collaboratively in the industry—promises an even larger role in enhancing reliability. And fourth-generation controllers using either Insulated Gate Bipolar Transistor (IGBT) or Insulated Gate Commuted Thyristor (IGCT) power electronic devices as valves promise further to reduce the cost and increase the functionality of power electronics-based controllers. Further down the road, the silicon-based thyristors used in current devices can be replaced with thyristors based on wide bandgap semiconductor materials, such as silicon carbide, gallium nitride, or very thin-film diamond materials.
The bigger picture involves more than just power controllers. These devices will be only one part of a broader system, an intelligent grid that includes automated capabilities to optimize the performance of the system, respond to disturbances instantly to minimize impact, and restore the system after a disturbance. The basic building blocks include advanced sensors, enhanced computational ability, pattern-recognition software, and these controllers.
The sister of power reliability is power quality. In applications from manufacturing assembly lines to home appliances, microprocessors now number more than 12 billion in the United States alone. These digital devices are highly sensitive to even the slightest disruption in power quality—an outage of less than a fraction of a single cycle can disrupt performance—and they are sensitive to variations in power quality due to transients, harmonics, and voltage surges and sags.
Improving power quality may require a two-pronged, technology-based approach. On the one hand, the ability of end-use devices to tolerate power-quality fluctuations can be enhanced using small embedded ultra-capacitors or filters. On the other hand, the ability to deliver higher quality power can be enhanced through the use of self-sufficient microgrids and other means. Tackling this problem from both directions will help reduce the very high cost of degraded power quality.