(April 2012) MidAmerican Energy awarded a contract to Siemens Energy to supply wind turbines for its 407-MW project expansion. American Electric Power began operating the 580-...
End the Gridlock: Why Transmission is Ripe for New Technology
devices improve the controllability, stability, and power transfer capability of AC transmission systems. These technologies have been under development for more than a decade, and within the past few years, several different types of FACTS devices have been successfully demonstrated in Texas, Kentucky, New York, and elsewhere; several FACTS technologies are fully commercial.
Superconducting Magnetic Energy Storage. Using a combination of stored real power and high-speed electronics in a mobile, trailerized system, SMES allows users to "cache" large amounts of power close to customer loads. Used for several years for industrial power quality protection, the technology now is being deployed as a low-cost solution for wide-area grid stability problems. A new configuration known as "Distributed SMES" or "D-SMES" offers grid operators the ability to dampen out voltage disturbances, and thereby increase line ratings, by injecting large amounts of both real and reactive power, instantaneously, at multiple locations on a grid. It can be deployed rapidly to facilitate generator interconnections, increase available transfer capacity, and reduce reliance on so-called "reliability must-run" generation. Its mobility allows it to be relocated as system needs change.
High-Temperature Superconducting Cable. This new cable will use the extraordinary power density of HTS wire to provide a new solution for high-current urban distribution needs within the next few years. Initial deployments are expected to be in so-called "urban retrofit" projects in conventional AC distribution, such as the Pirelli Cables & Systems demonstration at a Detroit Edison substation that will be inaugurated this spring. This retrofit strategy will enable urban utilities to multiply the capacity of existing underground conduits without costly and disruptive excavation. Later, HTS cable could offer a new approach to address long-distance transmission.
HTS DC Transmission. Deployment of HTS cable in a direct current mode at medium voltage could yield tremendous synergies, especially in a deregulated environment with wide and volatile regional price disparities. Capable of carrying very large currents, such systems would be compact and highly efficient, and avoid the cost burdens associated with high-voltage terminal stations.
These semiconductor and superconductor materials form the basis for several new technologies that could improve power reliability, shrink the power infrastructure footprint, and support robust competition. (See sidebar, "Of Semiconductors and Superconductors.")
Given today's extraordinary power market dynamics, and the record of other industries that underwent deregulation, it is likely that these and other new power transmission technologies could attract significant investment capital on an at-risk, for-profit basis-if the conditions were right. Opening transmission to truly competitive entry could fortify competitive price discipline, reduce the need for generation investment, improve reliability, and depoliticize the grid-planning process. Investment decisions could be driven by anticipated trends in locational power prices, the surest indicator of the economic value of relieving bottlenecks in the transmission system.
But many issues must be addressed before widespread deployment of these technologies will occur. It is a given that the reliability and cost-effectiveness of new technologies must be proven. The more difficult issues and barriers, however, are likely to be institutional and regulatory in nature.
For example, traditional cost-based regulation could thwart the development of new