By Douglas J. Smith IEng, Senior Editor
The editors of Power Engineering have selected projects in the U.K., U.S. and the Philippines as 2003 Projects of the Year. Two projects, one in Brazil and the other in the U.S., received Honorable Mentions. The three winning projects are:
- Tampa Electric’s Bayside Power Station, Tampa, Florida
- GE Power System’s Baglan Bay Power Station, Port Talbot, South Wales, U.K.
- San Roque Power Corporation’s San Roque Multi-Purpose Project, Island of Luzon, Philippines
The owners of the winning “Projects of the Year” were presented with their awards during the Keynote Session at POWER-GEN International on December 9, 2003 in Las Vegas.
Bayside combined-cycle repowering project. Photo courtesy of Sargent & Lundy LLC.
Bayside Power Station
In 1999 Tampa Electric reached an agreement with the U.S. Environmental Protection Agency and Florida’s Department of Environmental Protection to decrease overall emissions from the company’s power plants. A major component of the plan was the repowering of Gannon Station’s coal-fired Units 5 and 6 into a 1,750 MW, two unit, gas-fired combined-cycle power station. The new power plant was renamed Bayside Power station. Gannon’s coal-fired Units 5 and 6 were 250 MW and 350 MW, respectively.
An analysis performed by Sargent & Lundy LLC determined that re-using Unit 5’s existing steam turbine would require three gas turbine/HRSG drive trains. However, because of the higher capacity of the steam turbine on Unit 6, four gas turbine/HRSG trains would be needed for repowering that unit.
Bayside Unit 1’s combined-cycle configuration includes three GE 7FA gas turbine generators coupled to three Alstom Power heat recovery steam generators (HRSG). Unit 2 has four gas turbines and four HRSGs. Steam from the HRSGs is used to run the original steam turbines. The output of Units 1 and 2 are 750 MW and 1,000 MW, respectively.
Besides the installation of the gas turbine/HRSG trains on Units 1 and 2, the project includes a new control and administration building, a condensate polishing system addition, new maintenance shop, warehouse building and auxiliary cooling towers. In addition, the fire protection, station air, instrument air and the demineralized water systems were upgraded.
The Bayside repowering project faced many challenges. The original Gannon power plant site is long and narrow, with water to the north and west, a county road to the south, and a property line on the east of the plant. These space restrictions complicated project execution because Gannon’s remaining six coal-fired units had to remain on-line during the 2-1/2 year construction phase of the repowering project. As a result, all of the support services, including the coal yard, had to remain in place and in operation.
The site chosen for installing the gas turbine/HRSG trains was in an area where the remnants of three fuel oils tanks were still in place. Although the location provided sufficient space for the new units, the distance of the existing steam turbines from the new gas turbines necessitated the construction of a 1,900 ft-long pipe rack.
Construction of Unit 1, by TIC-The Industrial Company, was completed one week ahead of schedule and was put into commercial operation on April 24, 2003. Unit 2 is still under construction but it is predicted that its construction will be completed on or possibly ahead of the January 2004 schedule. Since start of construction, the existing six coal units had remained on-line providing Tampa Electric with 1,200 MW of capacity.
Repowering of Gannon Units 5 and 6 to the Bayside combined-cycle plant has provided many benefits to Tampa Electric and their customers. A significant benefit has been a reduction of more than 97% in NOx and SO2 and more than 88 o/o reduction in particulates. Additionally, the repowering project provides Tampa Electric a better diversity in its fuel mix. The age of the utility’s fleet of power plants has also been reduced by more than 66%.
By utilizing existing substation and transmission facilities and re-using other plant equipment, the cost of the repowering project was substantially lower than a similar sized greenfield installation. Even though the Bayside project faced many challenges, good teamwork among the owner, engineer and constructor has allowed the units to remain on or ahead of schedule.
“The Bayside Project is a major success for Tampa Electric, strongly supporting our emphasis on our core operations while significantly reducing air emissions from the facility. Superior teamwork between all of the parties involved with the project was key to meeting our goals,” says Chuck Black, Senior Vice President Generation, Teco Energy. Tampa Electric is a subsidiary of Teco Energy.
Baglan Bay Power Station
What is reported to be the world’s most advanced gas turbine is now in commercial operation at the Baglan Bay Power Station in Port Talbot, South Wales, U.K. GE Power System’s H System technology, a single shaft, combined-cycle system, is designed to achieve 60% thermal efficiency when operating on natural gas.
The major feature of the H System is GE Power System’s 50-Hz 9H gas turbine. With a length of 39-feet, a diameter of 16-feet and a weight of 811,000 lb, the 9H is believed to be the largest gas turbine in the world. Compared to today’s most efficient combined-cycle plants that operate with an efficiency of 57 to 58%, an H System gas-fired combined-cycle plant has the potential to save up to $2 million annually in fuel costs.
The H System, which was developed by GE as part of the U.S. Department of Energy’s Advanced Turbine System Program, features a closed-loop steam cooling system. Because the steam cooling system permits a higher firing temperature of 2,600 F, it increases the combined-cycle efficiency while keeping combustion temperatures at levels consistent with low emissions.
Baglan Bay Power Station, Port Talbot, South Wales, U.K. Photo courtesy of GE Power Systems.
In order to withstand the higher temperatures, and increase the service life of the gas turbine, the first stage buckets and nozzles have been designed with single-crystal materials. A dense vertically cracked thermal barrier coating is used to insulate the nozzle and bucket base metals from high combustion gas temperatures.
Preparing the 9H gas turbine for testing. Photo courtesy of GE Power Systems.
GE leased the land for the construction of the Baglan Bay Power Station from BP Chemicals Ltd. The plant, operated by GE’s European Operations & Maintenance Group, provides electricity and steam to the Baglan Energy Park and BP Chemical’s Baglan isopropanol plant. Any surplus electricity is sold into the U.K. national grid. In addition to the H System, the Baglan Bay Power Station also has a 33 MW combined heat and power plant powered by a GE LM2500 gas turbine.
“The H System is the world’s most advanced single-shaft combined-cycle system,” says Don Hoffman, H System product manager for GE Power Systems. The H System is a single GE 109H combined-cycle package rated at 480 MW of electricity. During initial testing at the plant the H System generated 530 MW at 44 F for the U.K. national grid.
According to Hoffmann, the H System represents the most thoroughly tested industrial gas turbine technology since the company’s founding. Utilizing over 7,000 sensors installed throughout the system, the company was able to validate operation of the closed-loop steam cooling system to permit higher firing temperatures. Following the successful conclusion of these tests, the instrumented gas turbine components used to gather data were replaced with commercial non-instrumented components.
A large percentage of the H System design was based on proven turbine technology. The compressor design utilized many features of the compressors used for the CF6-80C2 aircraft engine and its aeroderivative, the LM6000 gas turbine. A dry low NOx combustion system, which mixes the fuel and air prior to ignition, reduces the 9H’s NOx emissions to less than 25 ppm.
San Roque Multi-Purpose Project
The $1.2 billion San Roque Multi-Purpose Project is located on the Lower Agno River, in remote mountains approximately 140 miles north of Manila in the Philippines. According to Washington Group International, the engineer-procure-construct (EPC) contractor, the project is one of the largest hydroelectric, flood control and irrigation projects in Asia.
Considered a national flagship project, San Roque was built to provide a reliable and renewable 345 MW of power to the Philippine National Power Corporation (NPC), reduce flooding and provide year-round irrigation for 87,000 hectares (217,500 acres) of farmland. Another benefit of the project is it will improve water quality by trapping upstream sediment in a large reservoir.
Construction of steel-lined section of San Roque power tunnel. Photo courtesy of Alfred E. Belen, Jr., “Images of the San Roque Dam—2002.”
San Roque Power Corporation (SRPC) developed the project for NPC in a build-operate-transfer arrangement. Once the project achieved commercial operation on May 1, 2003, ownership of the dam, spillway and low-level outlet tunnel was transferred to NPC. However, SRPC will own and operate the generating facilities for 25 years. The SRPC is a special purpose company formed by Sithe Philippines Holdings, Inc., Marubeni Corporation of Japan and KPIC Singapore Pte. Ltd.
In 1998 SRPC awarded two separate contracts, totaling $705 million, to two subsidiaries of Washington Group International. The contracts included design and construction of:
- A 640-ft high rock-fill dam (The 12th highest dam of its kind in the world)
- Underground powerhouse with three 115 MW turbine generators
- A gated concrete spillway (328-ft wide x 1/4–mile long with a vertical drop of 550-ft)
- A five square mile reservoir to store water for power generation and irrigation
- A power tunnel/penstock for routing water from the reservoir to the power house
- A low-level outlet tunnel
Arial view of completed San Roque Multi-Purpose project. Photo courtesy of Washington Group International
At its peak the San Roque project employed 5,000 people. In good weather the site was a one-hour drive from the nearest city. Because the area was virtually void of any infrastructure, 40 miles of access roads had to be constructed. In addition, the contractor had to construct a village for 150 management and 800 craft personnel. The village included housing, dining facilities, commissary, infirmary, school, recreation facilities, laundry, a 22 MW power plant, a 4160 volt power distribution system, and water purification and sewage treatment facilities.
Permanent plant equipment and heavy construction equipment and materials had to be delivered by barges from the main port terminals to a holding site on the coast. From this holding area the equipment and materials were then transported by road to the site. A 500,000-gallon fuel depot was erected to supply a secure and continuous supply of fuel for the heavy construction equipment and the 22 MW construction power plant. At any one time the project had $8 million in spare parts on hand for the maintenance and servicing
of the heavy construction equipment. This was necessary because planned maintenance and repair of the equipment was continuous—24 hours per day seven days per week.
Since the project site, including temporary areas for equipment lay down, encompassed approximately ten square miles during the construction phase of the project, the work was divided into four major areas with their own area managers:
- Underground works
The project’s design was originally established in the late 1970s. However, Washington Group International revised this design to incorporate the latest materials and technology to improve the ability of the dam to withstand earthquakes. The first phase involved the building of an upstream cofferdam and three 2,600-ft long tunnels to control the river flows and to divert the river around the dam foundation. These diversion facilities were designed to handle a 100-year flood.
In July 1999, the Agno river was diverted around the dam site and work on the dam’s foundation commenced. The main cofferdam and the rock-fill dam required extensive excavation and removal of loose material before the contractors were able to reach the bedrock. Although the normal operating level of the reservoir is 918-ft above sea level, the dam is able to handle a reservoir level of 950-ft during typhoons. The gated concrete spillway has been designed and constructed to discharge 452,000 ft3 of water per second.
Water from the reservoir to the turbines is carried through a 4,200-ft x 27-ft diameter power tunnel. The final section approaching the powerhouse is steel lined. As it enters the powerhouse, the power tunnel is split into three steel-lined penstocks that directs the water flow into the plant’s three turbine generators. Each turbine can be operated independently from the central control room.
A concrete surge shaft 66-ft in diameter and extending 328-ft below ground level intersects the power tunnel. This protects the tunnel from forces produced by sudden unit shutdowns. The low-level outlet tunnel is 18-ft in diameter and 4,130-ft long.
A major part of the San Roque Multi-Purpose Project was the employment and training of local staff. Washington Group International trained former farmers and taxi drivers to become world-class construction equipment operators. Cross-cultural training also helped to promote understanding between people from different backgrounds. According to Washington Group International extensive safety training programs helped the project to achieve an impressive safety record. At one time nine million man-hours were worked without a lost-time accident occurring.
Patrick J. McAllister, president and CEO of the San Roque Power Corporation, states that the Washington Group construction arm provided a world class level of training in construction and safety that has benefited thousands of workers employed in the construction of the project. These new skills will allow the workers to go anywhere in the world and earn enough money to provide them and their families with a decent standard of living, says McAllister.
Pleasants Power Station SCR
With a commitment to achieve clean air compliance by May 2003, Allegheny Energy Supply Co., LLC and Monongahela Power Company awarded a contract in late 2000 to Parsons E&C for the design, procurement and installation of selective catalytic reduction (SCR) system on two 650 MW coal-fired units at their Pleasants Power Station.
Charged with achieving NOx reductions greater than 92% at two-ppm ammonia slip, the engineers were also asked to review the possibility of reducing the overall size of the reactors to reduce costs. After analyzing the SCRs, the project team determined that the catalyst chambers could be shortened by four-feet on each level while still remaining in compliance. Because of the narrow space for installing the SCR, it had to be rotated 90 degrees. The gas flows vertically through the SCR. Nonetheless, all of these modifications were made without compromising the ability of the SCR to accommodate all major catalyst manufactures.
To avoid health and safety risks to the local community and the plant, a Hamon Research Cottrell/Wahlco urea-to-ammonia process generates all of the required ammonia onsite. Not only does this eliminate transportation of ammonia to the site it also removes the need for storing large quantities of ammonia at the plant.
Pleasants Power Station SCR retrofit. Photo courtesy of Parsons E&C.
Through prototype testing and full-scale operation of the same type of urea-to-ammonia system at another Allegheny Energy power plant, the engineers were able to reduce the size of the urea-to-ammonia reactor. This was done while maintaining 100% backup capacity for the operation of the SCRs on both units at the Pleasants Power Station. Utilizing regular planned maintenance outages, the final tie-in of the SCR was completed on Unit 1 in March 2003 and Unit 2 in April 2003.
Utilizing innovative design and construction approaches, the project was completed on time and under budget. During the 2003 ozone season, the Pleasants Power Station SCRs met the utility’s goal of reducing NOx by over 92% with minimum ammonia slip.
Macae Rio Claro
Remote site, labor problems, cultural and ethnic differences, and continual changes to the contracted interconnection’s scope of work by the local utility were some of the challenges in the construction and startup of the Macae Rio Claro power project in Brazil. The plant, located adjacent to the Macae river, is 28 km northeast of the coastal town of Macae, Brazil. Because the terrain surrounding the plant site consisted of rolling hills, extensive excavation was required before any construction could commence.
In October 2000 El Paso Energy, in conjunction with El Paso International do Brazil Ltda., commenced the design, procurement and construction of the simple-cycle IPP Macae Emergency Power project. The original contract called for the installation of 16 GE LM6000PC water injected simple-cycle aero-derivative combustion turbines. A contract for four additional combustion turbines was signed in February 2002.
Since September 2002 all of the plant’s 20 combustion turbines, operating in simple-cycle, have been in commercial operation. Under an interconnect agreement with the local utility, El Paso Energy International do Brazil Ltda was required to construct a 345 kVA utility station. Electricity from the Macae plant, interconnected through the utility station, supplies 895 MW of electricity to the northern and southern grid systems of the state of Rio de Janeiro.
Macae Rio Claro Power Plant Brazil. Photo courtesy of El Paso.
The different languages, culture and work ethics between the U.S. subcontractors, and Brazilian subcontractors caused constant work interruptions. However, this problem was resolved when El Paso’s project management team took a more active role in overseeing the day-to-day activities of the subcontractors.
Although El Paso had labor agreements with the local subcontractors the labor force walked out on numerous occasions. The reason for the walkouts included more pay and time off and better benefits. Another complaint was the alleged mistreatment of the workers by the subcontractors that had hired them. Because of financial and productivity problems, El Paso was forced to fire and replace the mechanical and electric subcontractor. This negatively impacted the schedule by approximately six weeks.
Even with these problems Grady Blakley, senior vice president, El Paso Global Power Operations & Engineering, states that the Macae project was a very successful project for the company.
Projects of the year 2003: Major Vendors
Bayside Power Station
- Sargent & Lundy LLC
- TIC-The Industrial Company
- General Electric
- Alstom Power
Baglan Bay Power Station
- GE Power Systems
- Toshiba Corporation
San Roque Multi-Porpose Project
- Washington Group International,Inc.
- Toshiba International Corporation
- Ishikawajimi-Harima Heavy Industries
- ITT Flygt
- Konecranes Landel
Pleasants Power Station SCR Project
- Parsons E&C
- Haldor Topsoe
- Hamon Research Cottrell/Wahlco
- TLT Babcock
- MC Mechanical
- Kvaerner Songer
Macae Rio Claro Power Plant
- El Paso Engineering & Construction
- General Electric
- Kvaerner Engineering
- Construtoras Andrade Gutierrez, Brazil
- Equisales Associates, Inc.