Gas

A web supplement to the September issue with details of global power shortages.

Heat waves, droughts, and other weather and climate phenomena; economic woes; aging or inadequate infrastructure; fuel shortages. These are some of the most obvious causes that have led to record peaks in power demand or sudden drops in available capacity. The results have been sometimes debilitating load-shedding, brownouts, and blackouts around the globe this summer (and, in some cases, for much longer). Here’s an overview of which countries are affected by which difficulties. For a more detailed look at the extent of shortages and what’s causing them, visit Web Exclusives at https://www.powermag.com

A brush fire that spread and detonated explosives stored at the Evangelos Florakis naval base in Mari on the southern coast of Cyprus on July 11 killed 13 people, injured 62 others, and severely damaged the Vassilikos Power Station—an oil- and gas-fired plant that supplied almost 60% of the island nation’s power. Cyprus, which was once considered an “economic miracle,” has been battling crippling power shortages that have beleaguered its financial and tourism sectors since the blast and left it on the verge of economic collapse.

In 2010, the 2,310-MW Adapazari Power Plant achieved 99.8% availability, which is nearly 7% higher than the industry average and a global record in F-class gas turbine technology. The new turbine upgrade is helping ENKA Power bolster Turkey’s evolving economy by improving its energy sector’s efficiency and productivity.

Known for its progressive, pro-sustainability policies, the City of Tallahassee recently repowered a 30-year-old conventional steam plant unit, turning it into a new 300-MW facility. The utility redesigned the Arvah B. Hopkins Generating Station, Unit 2 as a 1 × 1 combined cycle plant in order to improve efficiency, switched the primary fuel from oil to natural gas, and thereby reduced fuel costs and emissions. The plant’s flexible design even will enable expansion to a 2 × 1 configuration when additional capacity is needed in the future.

Just as GE Energy, Siemens, and Mitsubishi Heavy Industries (MHI) in May announced gas combustion technology developments—each seeking to push the 60% barrier with new gas turbine designs—Alstom has quietly been upgrading its KA26 combined cycle power plant. (See the July 2011 “Global Monitor” for more information on the GE, Siemens, and MHI turbines.) The firm says that the next generation of the 500-MW power plant, based on the advanced class GT26 gas turbine, features “achievable” efficiencies of over 61%, increased flexibility, and more than 350 MW, which can be delivered in less than 15 minutes to help integrate renewable energy sources (Figure 3).

Two years after it laid the foundation stone, Germany’s E.ON on June 27 opened Hungary’s most efficient combined cycle gas turbine (CCGT) power plant (Figure 7). The €400 million ($573 million) plant in Gönyü has a capacity of 433 MW and an efficiency of over 59%, E.ON claims. Siemens supplied the main components: an SGT5-4000F gas turbine, an SST5-5000 steam turbine, an SGEN 5-3000W generator, and the entire electrical and instrument and control equipment. The natural gas–fired power plant is of single-shaft design with the main components arranged in a single driveline.

CTG Universidad is a two-unit combustion turbine plant commissioned in late 1970 by the Comisión Federal de Electricidad (CFE) on the north side of Monterrey, Mexico’s third-largest city and an important industrial center. By the 1990s, the two 14-MW turbines were obsolete, used sparingly, and slated for demolition in 2010. However, by 2002, portions of Monterrey began experiencing power restrictions caused by a lack of sufficient reactive power production, and that situation presented an opportunity for the plant. By repurposing an old combustion turbine for use as a synchronous condenser to provide local reactive power, CFE significantly reduced local power supply limitations. For that savvy plant repurposing, CFE’s CTG Universidad Unit 2 is the winner of POWER’s 2011 Marmaduke Award for excellence in power plant problem-solving. The award is named for Marmaduke Surfaceblow, the fictional marine engineer and plant troubleshooter par excellence.

Cycling your steam power plant is inevitable, so now is the time to learn how to minimize equipment damage and assess the true costs of cycling. Whether cycling is required by the grid operator because of renewable integration or other factors, you must be proactive about updating operating processes and upgrade equipment so the transition to cycling operation goes smoothly.

As coal-fired power plants increasingly operate in cycling modes, many plants are confronting the potential for higher levels of component damage and degraded performance of environmental control equipment. Generators and EPRI are working together to find ways to mitigate the effects of cycling operation and to manage the transition of formerly baseload plants to flexible operation.