Large-particle ash (LPA), also called popcorn ash (Figure 1), is a serious concern for many coal-fired utility boiler operators who have retrofitted their unit(s) with a high-dust selective catalytic reduction (SCR) system. LPA formed in the boiler can easily carry over into the SCR reactor (Figure 2), where it often causes catalyst erosion damage and […]

The February 1907 issue of POWER magazine reported on the construction of a new coal-fired steam engine plant on the Merrimac River outside of Lawrence, Mass. According to the plant’s owner, "the simplest and most flexible means for handling coal… to the furnace is by animal muscle… that brings the coal to the firing floor […]

When Charles Dickens began A Tale of Two Cities with, "It was the best of times, it was the worst of times," he was referring to the French Revolution of the late 18th century. But Dickens’ words apply equally well to the American generation industry of the late 20th century. A decade of overbuilding U.S. […]

To borrow shamelessly from Charles Dickens, one of my favorite authors, for coal in 2006, "It was the best of times, it was the worst of times." No Escape The year began in horror. On January 2, most likely a result of a severe lightning strike, methane gas in the International Coal Group’s Sago Mine […]

Fireproofing switchyards From an insurance carrier’s perspective, we fully condone the use of on-line condition monitoring for large, critical transformers ("Monitoring key gases in insulating oil keeps transformers healthy," POWER, October 2006). However, another issue that the transformer failure and subsequent fire at Arizona Public Service’s West Wing Substation in 2004 highlights is the need […]

Safeguarding coal-handling assets;
Giant wind turbine hard to bear

  What’s in a name? Plenty, if the word is "renewable." Intuitively, most people outside the energy industry consider hydroelectric power "renewable." The dictionary defines the word as follows: "capable of being replaced by natural ecological cycles." Accordingly, rainwater should indisputably qualify as renewable. Yet since the early days of renewable portfolio objectives, most hydro […]

The use of longer steam turbine last-stage blades (LSBs) reduces the number of low-pressure casings and, thus, a turbine’s total installed cost. In many cases longer blades extract more energy from low-pressure steam before it enters the condenser and improve a turbine’s overall thermodynamic efficiency. But creating longer blades requires forsaking conventional design techniques for complex aerodynamic analysis of stationary vanes and rotating blades. Has the market push for longer LSBs exceeded current technology limits? Does the industry conduct proper analysis to determine when using longer blades is beneficial or not?

An offshoot of the 1993 Megatons to Megawatts nonproliferation program, the Blended Low-Enriched Uranium (BLEU) project has modified and developed new fabrication processes for converting surplus weapons-grade uranium materials into nuclear fuel for TVA’s Browns Ferry Nuclear Plant. This innovative public/private venture continues to deplete nuclear arsenal stockpiles while reducing storage, security, and disposal costs to U.S. taxpayers.

Utility resource planners are used to viewing new generation in terms of firm, dispatchable capacity. Dispatching a renewable resource such as wind requires a different perspective. Wind capacity can serve as a hedge against fossil fuel price risks and perhaps future emissions restrictions, but it requires a much more structured planning horizon. Integrating wind farms into their portfolios may be the most difficult challenge utilities face today.

The wind energy business is beginning to look as frenetic as the merchant gas-fired power business in the late 1990s—with some critical differences. If the 10 issues listed here are addressed soon, wind power may avoid a crash and burn similar to the one that beset the gas turbine business.

In chemistry, osmosis refers to the movement of water molecules through a selective membrane from an area of low solute concentration to an area of high solute concentration, creating a pressure gradient. Researchers have recently demonstrated that exploiting this natural phenomenon could produce useful amounts of electrical power.

IT project engineering skills aren’t taught in college; they’re developed through on-the-job training with seasoned mentors. Begin honing your project management skills by firmly grasping the fundamentals presented in this article.

Harvard Business School Professor Clayton Christensen coined the term "disruptive technology" in his best-selling 1997 book, The Innovator’s Dilemma. According to Christensen, a disruptive technology unseats a dominant technology by creating products that are so much cheaper or better in one or more ways that they quickly become the new mainstream standard, transforming an entire […]

Renewables require rethinking just about everything/Torque-splitting drive train improves wind turbine reliability/Waste gas–burning engines reach milestone/Hybrid power plant targets pipeline losses/Power from paint/Gulf Coast Power Association conference report/Pat Wood talks about the challenges facing ERCOT

The U.S. electric utility industry has long encouraged its customers to get more value from their electricity dollar. Today, the industry—facing volatile costs and mounting concerns about the environment—is coming together to create a new role for energy efficiency—one that enables technology to deliver more value to customers and electric utilities alike. For example, "smart" […]

The visible consequences of sulfuric acid aerosol emissions—opaque stack emissions called “blue plumes”—are merely the tip of an iceberg. In sufficient concentration, SO3 also can increase corrosion and fouling of equipment and components downstream of the furnace while decreasing their efficiency and penalizing overall plant heat rate.

More top utilities are making plans to add one or more integrated gasification combined-cycle (IGCC) plants to their generation portfolios over the next decade. Some 25 separate projects are on the drawing board, virtually all planning to use Eastern coal. Western coals pose tougher challenges for gasifiers, and their lower heat content disadvantages project economics. […]

First live superconducting cable / Biggest CO2 storage project / Largest hydrogen-fueled plants / Record run for fuel cell cogen system / Largest PV plant still in Bavaria / Luz returns to U.S. / POWER digest

Upgrading to digital–twice / Lower-cost turbine monitoring / Pros and cons of remote process control / Nuts about Superbolt

Most sponsors of bid solicitations seek to attract the maximum number of high-quality bids. Basic economic principles tell us that the greater the number of respondents to a solicitation, the greater the competition and the greater the benefits to the solicitor. Somewhat counterintuitively, and notwithstanding California’s need for more electricity supply, the state’s utilities are […]

The O&M staff of AES Westover Station wisely took a holistic approach to optimizing combustion within Unit 8’s boiler in order to reduce its NO_x emissions while maintaining acceptable levels of carbon-in-ash content. The results of major modifications—centered on the addition of a fan-boosted overfire air system—were a 60% reduction in NO_x levels, improved unit reliability, and a project payback period measured in months rather than years. As this project proved, the whole is more than the sum of its parts.

Fuel flexibility isn’t free. Whether you’re equipping a new power plant to burn more than one type of coal or retrofitting an existing plant to handle coal blends, you’ll have to spend time and money to ensure that all three functions performed by its coal-handling system—unloading, stockout, and reclaim—are up to the task. The first half of this article lays out the available options for configuring each subsystem to support blending. The second half describes, in words and pictures, how 12 power plants—both new and old—address the issue.

Slagging and fouling of furnaces and boilers’ convective pass top the list of costly coal plant O&M problems. Although sootblowing is a tried and true solution, running sootblowers too often can erode boiler tubes. Lehigh University’s Energy Research Center has developed an "expert" sootblowing system that has outperformed experienced operators’ "seat of their pants" sootblowing procedures on two head-to-head field tests.

For some gencos, the dearth of operating experience for integrated gasification combined-cycle plants adds too much uncertainty to the risk/reward equation for new-capacity technology options. For others, the possibility of being able to comply with air pollution limits as far out as 2018, as well as to meet all-but-certain CO₂ caps, makes IGCC well worth investing in—now.

Concerns about global climate change have prompted interest in reducing or eliminating the carbon dioxide (CO₂) emissions of fossil fuel-fired power plants. Here’s a guide to the technology and economics of three CO₂ capture methods: postcombustion separation of CO₂ from flue gas (applicable to existing plants), and oxygen-fired combustion and precombustion capture (suitable for new coal-fired capacity, including IGCC plants).

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.

In his keynote speech this May to the Global Roundtable on Climate Change, held in Iceland and hosted by the Earth Institute of Columbia University, Ólafur Ragnar Grimsson—the president of Iceland—challenged government and business leaders to take measurable steps now to build a prosperous and sustainable future through smart science and public policy. Grimsson’s call […]