Features

In 2005, Xcel Energy fully implemented its unique Utility Innovations initiative to encourage its IT vendors to work together. One pilot project completed under the UI umbrella confirmed that tighter integration of predictive and analytical systems and data can optimize preventive maintenance intervals, reducing costs and downtime while increasing profits and productivity.

Large T&D-sized transformers age as quickly as generating assets do. But preventing transformers from failing is difficult because they have no moving parts and are sealed up. Tracking the concentrations of certain gases—the more, the better—that are dissolved in a unit’s insulating oil is a proven way of detecting damage before it causes a costly problem.

The first megawatt-class sodium sulfur (NaS) battery placed in service in North America was installed this June in Charleston, W.Va. The 1.2-MW system—comprising the battery and a bidirectional inverter—can be discharged during the day to provide 7.2 MWh of on-demand power for shaving peak loads and be recharged at night. It’s no longer true that electricity can’t be stored, except in small quantities.

Point Aconi’s circulating fluidized-bed boiler experienced erosion, corrosion, and fouling problems from the day it went on-line in 1993. After several frustrating years of unreliable operation, in late 1999, Nova Scotia Power discovered the right combination of engineering and fuel modifications. Today, after a switch to 80% petroleum coke and major boiler modifications, Point Aconi’s output exceeds its original nameplate rating. For having the vision and fortitude to plan and execute a multiyear, $20 million project to revitalize North America’s first in-service utility CFB boiler, Nova Scotia Power’s Point Aconi plant is the well-deserved winner of POWER magazine’s 2006 Marmaduke Award for excellence in O&M.

Among utility chemists, opinions differ on the effect that organic compounds—both naturally occurring types and those added as treatment chemicals—have on the steam cycle. Some chemists raise the specter of corrosion of low-pressure turbines caused by organic acids created as the compounds degrade. Others defend and encourage the use of organic treatment chemicals, particularly neutralizing amines, by pointing to a long and positive history of their use in boiler and feedwater systems.

Performance testing after initial start-up has value well beyond the short-term goal of validating equipment guarantees—it’s your only opportunity to establish the baseline performance of the overall plant and many of its major systems. Corporate bean counters may be interested in short-term results, but a good plant engineer understands that a thorough performance test will be useful for many years. Here’s your guide to each facet of a performance test—plus pitfalls to avoid.

Complying with permitted emissions limits may be the most significant operations risk for a power plant. As limits are slowly ratcheted downward, understanding the accuracy and variation of measured pollutant levels becomes even more important. To avoid misunderstandings, regulators and plant owners should factor measurement uncertainty into air quality permit numbers both as the permit is formulated and preceding any subsequent modifications.

An extremely reliable North American bulk power system—one that consistently delivers uninterrupted power to every user—is not a dream that must be made reality. To a large extent, that is what we have today. With the exception of infrequent (and therefore, newsworthy) outages, the system has never been more dependable. Nevertheless, with the great northeast blackout of August 14, 2003, still fresh in memory, Congress saw fit to include electric reliability measures in the Energy Policy Act of 2005.

Stainless steels and nickel alloys of the C-family are major materials of construction for flue gas desulfurization systems. Both types of materials depend upon the presence of thin, passive, chromium-rich, surface-oxide films to provide the desired corrosion resistance. Corrosion resistance is optimized by proper cleaning before and after fabrication. Here are some guidelines for keeping those materials clean.

Steve Elonka began chronicling the exploits of Marmaduke Surfaceblow—a six-foot-four marine engineer with a steel brush mustache and a foghorn voice—in POWER in 1948, when Marmy raised the wooden mast of the SS Asia Sun with the help of two cobras and a case of Sandpaper Gin. Marmy’s simple solutions to seemingly intractable plant problems remain timeless.