Archive: Gas

Flexible Turbine Operation Is Vital for a Robust Grid

Renewable electricity generation has many environmental advantages, but adding large amounts of far-flung renewable resources to a grid requires increased operating flexibility from dispatchable generators when the wind doesn’t blow or the sun doesn’t shine. One promising option: A combined-cycle plant based on Alstom’s GT24/GT26 combustion turbine can be “parked” at approximately 20% plant load while producing emissions comparable to those during baseload operation—with little loss in thermal efficiency. When demand returns, the combined cycle can return to baseload within minutes.

Top Plant: West County Energy Center, Palm Beach County, Florida

The 3,600-MW West County Energy Center, with two recently commissioned power blocks and a third just entering start-up, is the first “greenfield” combined-cycle plant constructed by FPL since the 1970s. Thanks to FPL’s long history with repowering projects, the project team commissioned Unit 2 seven months early, with no operator errors during start-up. At just over $600/kW, the cost of the plant was a bargain.

Top Plant: Timelkam Power Plant Vöcklabruck District, Upper Austria, Austria

Now that the 412-MW Timelkam Power Plant has replaced a 47-year-old coal-fired power plant located in the Vöcklabruck District, northern Austrians can bid auf wiedersehen (goodbye) to high levels of air pollution. Compared to its predecessor, the new gas-fired combined-cycle plant has dramatically cut CO2 and NOx emissions and produces seven times more energy.

Protect Your Stack Linings from Corrosion

Stacks at power generating stations may be low maintenance, but they are not no maintenance. The cost of preventing corrosion may be as little as $10,000, but the cost of repair or replacement could be many times that or even put your plant out of commission until the stack problem is corrected.

Local Warming: Helsingin Energia Uses CHP to Heat a City

Power plant operators, especially those located in countries with enforceable carbon emissions standards, are concerned about their CO2 emissions. But for Helsingin Energia—which provides power, heating, and cooling for Helsinki, Finland’s 300,000 residents—the main concern is local warming, not global warming. In Helsinki, temperatures on midsummer afternoons only reach an average 21C, and for half the year daytime temperatures are below 10C.

Breathing Added Life into Failing Heat Exchangers

When heat exchanger tubes—sometimes numbering a thousand or more per unit—begin to crack or wear, the effects can lead to a cascade of subsequent failures in adjacent tubes. If too many tubes are plugged, heat exchanger effectiveness is compromised, and power generation may be curtailed. If conventional mechanical plugs are used, they can break loose, leak, and fail. At that point, the replacement of a very costly heat exchanger is imminent.

High-Efficiency Gas Turbines Go to Market

This May, following two years of construction, Siemens Energy put into operation Irsching 5, an 847-MW advanced combined-cycle power plant near Ingolstadt, Germany. The plant’s owner, Gemeinschaftskraftwerke Irsching GmbH—a joint venture of E.ON, Mainova, and HEAG Südhessische Energie—features two SGT5-4000F gas turbines, one SST5-5000 steam turbine, three hydrogen-cooled generators, electrical systems, and Siemens’ SPPA-T3000 instrumentation and control system.

Luminant’s Oak Grove Power Plant Earns POWER’s Highest Honor

Luminant used remnants of the ill-fated Twin Oaks and Forest Grove plants (which were mothballed more than 30 years ago) to build the new two-unit 1,600-MW Oak Grove Plant. Though outfitted with equipment from those old plants, Oak Grove also sports an array of modern air quality control equipment and is the nation’s first 100% lignite-fired plant to adopt selective catalytic reduction for NOx control and activated carbon sorbent injection technology to remove mercury. For melding two different steam generators into a single project, adopting a unique and efficient “push-pull” fuel delivery system, assembling a tightly integrated team that completed the project on time and within budget, and for completing what was started almost four decades ago, Oak Grove Power Plant is awarded POWER magazine’s 2010 Plant of the Year award.

Industry Pivots on Natural Gas, Hails Cap and Trade

At the opening ELECTRIC POWER 2010 plenary session, both the keynote speaker’s address and discussion among the Power Industry Executive Roundtable participants pointed to the renewed appeal of natural gas and proposed cap-and-trade legislation as being potential game-changers for the U.S. power industry.