Mark Durka, Reliant Energy, Houston, Texas, USA, Mike Sumrow, S&S Energy Products, Houston, Texas, USA, David Wohleber, Reliant Energy, Houston, Texas, USA
In Shelby County, Illinois, a new power facility based on eight GE LM6000 aeroderivative gas turbine-generator sets is providing much needed peaking power to the Midwest markets of the USA. Five of the units were operational initially under a fast-track timetable, and a sixth unit was operational in mid-September 2000. The remainder will be installed between now and the end of 2000.
Figure 1. Shelby provides much-needed peaking power to the Midwest
The power plant, sited on 32 ha of land around 280 km south-southwest of Chicago, began commercial operation on schedule in July 2000. Electricity generated is sold on the open, deregulated market. The plant operates only as required to support demand for power, about four months or less per year, mostly during the day from June through to September when electricity demand for cooling is greatest.
The Shelby County facility is owned and operated by Reliant Energy. The company’s basic strategy on the unregulated power side is to trade and market around its own power generation assets that are either acquired or built. This assures reliability and optimizes not only the assets but also the trading and marketing component.
Trying to get a plant sited virtually anywhere in the USA can be a long, difficult undertaking. However, Houston-based Reliant Energy successfully negotiated over a four-week period to purchase the land where the Shelby County facility now sits. The plant is located entirely in the Neoga school district, increasing Shelby County’s tax roll by about $350 000 annually. This increased tax revenue will be useful, especially since Neoga taxpayers authorised a referendum to build a new elementary school last year.
Anatomy of fast track
In late 1999, Reliant Energy an international energy services and delivery company with $20 billion in annual revenue and assets totalling $30 billion decided to accelerate the fast-track schedule for the Shelby county facility in order to bring five GE LM6000 aeroderivative gas turbine-generator sets on line by the summer of 2000.
Even in a regulated power market, a 129-day construction project time schedule is difficult to meet. Thus, in the deregulated US market, it was a great accomplishment that Reliant Energy could rally together county officials, the local utility, equipment and contractors to bring the plant on line to schedule.
This new project timetable hastened the schedule for various suppliers, including S&S Energy Products, a GE Power Systems business. In September 1999, Reliant Energy contracted with S&S Energy Products to provide the two LM6000 gas turbine-generator sets for the project, as well as the balance of plant materials. An additional three LM6000s were added in November. The rapid time schedule brought together a tremendous team effort by Reliant Energy employees, other suppliers, contractors, the local utility, and area labour/craft workers.
Reliant Energy’s original plan was to have access to the site in early January 2000. However, the air permitting and hearing/public comment period caused the start of construction to slip to the end of February. This reduced the project schedule to three months.
During the public hearing and comment period, various organizations went on record to support the project as a result of the company’s ongoing, pro-active outreach with citizens and community leaders. Danny Maycroft, from Labourer’s International Union of North America Local 171, AFL-CIO, urged the Illinois Environmental Protection Agency (IEPA) to approve the Shelby County facility
He said: “Aside from actual jobs created, the economic ripple effect will also yield many benefits for our region. We expect every dollar paid out in payroll will be turned over at least seven times, aiding the economy of this area for years to come. We urge IEPA to expeditiously approve the necessary authorizations to let this project begin.”
Figure 2. The LM6000 is one of GE’s most popular aeroderivative gas turbines
Concern was raised over Reliant Energy’s use of water from nearby Lake Mattoon for the power generation process. An environmental consulting firm familiar with local demographics, Crawford Murphy & Tilly, Springfield, Ill., was commissioned to perform a study on the environmental impact the power plant would have on the lake. The study determined that the power plant would have no adverse effect on the lake.
Reliant Energy also went a step further as reported in the March 17, 2000, Effingham Daily News. “The power company donated $10 000 in seed money to the Friends of Lake Mattoon to help the citizen’s group obtain grants to preserve and improve Lake Mattoon and Lake Paradise. In addition, a staff ecologist at Reliant Energy is working to help improve the lakes.”
The non-profit Friends of Lake Mattoon were eager to establish a working relationship with Reliant Energy. During one meeting Friends of the Lake president Bill Totten told the community: “The power plant should be a net positive for Lake Mattoon. Although Reliant Energy will become a major user of lake water, it has demonstrated its genuine interest in improving and preserving Lake Mattoon. The City has agreed to sell Reliant Energy 1 818 400 litres of water per day during 2000 to a maximum of 350 million l/yr.”
He went on to say: “Lake Mattoon is 40 years old and has experienced erosion, siltation and pollution, which plague many lakes in the Midwest. As a result, the lake does not hold as much water, the covers are much swallower, and the recreational uses of the lake are severely hampered by years of drought, such as 1999, according to the association.”
The Shelby County Board of Commissioners also voiced an opinion about the facility. Thomas Hays, Chairman, addressing the IEPA in February, explained the effects on the environment that would result from such a plant being built.
“Reliant Energy has established itself as a reliable, steadfast operator in other areas of the country. It has been honoured for its water and air quality programmes, for waste recycling, not to mention wildlife management, habitat restoration and public education.”
The project proceeds
In late February, Reliant Energy signed the engineering, procurement and construction (EPC) contract with the joint venture of Black & Veatch, of Kansas City, Mo., and Barton Mallow, of Southfield, Mich. This enabled the EPC team to break into action once the air permit was issued on February 23, 2000. Teamwork was intense: workers were on site six days per week, running two shifts totalling 450 skilled professionals (325 on the day shift; 125 on second shift).
To help with the fast track schedule, S&S Energy Products employed many Six Sigma quality tools that, as a GE business, are an integral part of work processes. S&S Energy Products also conducted a sharing session with Reliant, Black & Veatch and the union craft. These sessions determined the best ways to achieve on time deliveries and an on time commercial operation date so Reliant could sell power to the open market for revenue.
Another important tool S&S Energy Products used was the Failure Modes Effects Analysis or FMEA. This identified two key things at the onset of the project: the need for all contractors and subcontractors to be on the same schedule; and the fact that backfeed from Ameren, the local utility, would not support the start-up test schedule. To address this issue, Reliant Energy deployed two portable, 650 kW diesel generators to close the gap in the schedule.
S&S Energy Products’ metrics and issues tracking accounted for all deliverables. Anytime S&S Energy Products identified a red flag issue it was raised to the highest levels and corrective action was applied. S&S Energy Products also used a process map to show where it was in the construction process and in what order the contractor wanted equipment delivered to the site. This was helpful in crystallizing for everyone what fitted where in the delivery and construction process.
S&S Energy Products’ cooperation extended to providing rapid delivery and start-up of each LM6000 gas turbine-generator set from the company’s Houston manufacturing facility. The LM6000s started arriving at the Shelby County facility on March 1, 2000, and the equipment was assembled in less than four months. S&S Energy Products also worked quickly when it came to unit start up. The gas turbines were started up in seven days or less and mechanical erection of the common support equipment by the EPC firm continued simultaneous to gas turbine erection and start-up.
Figure 3. When complete in 2001, the Shelby County facility will have a total capacity of 340 MW
The LM6000 is one of GE’s most popular aeroderivative gas turbines. To meet the tremendous increase in power needs throughout the USA, S&S Energy Products has experienced a significant rise in gas turbine demand. Two LM6000 PC models that use standard combustion systems that feature GE’s Sprint spray intercooling technology are currently in operation at the Shelby County facility.
The Sprint cooling lowers the high pressure compressor inlet temperature, which in turn effectively lowers the compressor discharge temperature. The system consists of an interstage mist injection system, which cools the low pressure booster discharge air. Water is injected into the airflow path through a series of 24 air-assisted spray injection nozzles located in the engine front frame. Air for the system is supplied from the engine’s eighth stage customer bleed extraction port.
By using the Sprint spray intercooling system with the LM6000s, the compressor pressure ratio can be increased and additional air can be directed through the compressor in order to increase the gas turbines output characteristics.
The modular, 60 Hz LM6000 gas turbine-generator sets use standardized S&S Energy Products designs with single-lift skid units. The two-piece skid assembly is sectioned between the gas turbine and the generator/main load gearbox, and is designed for convenient transportation.
- The brush air-cooled generators are designed to accommodate gas turbine power output over the full ambient air temperature range, and are sufficiently rated to accommodate future ratings increases. The gas turbines are controlled by Woodword Governor’s NetCon 5000 controls.
- The LM6000s are ideal for the plant as they can be started and stopped with ease to meet peak power demands. In fact, the LM6000s at this site can go from cold start to generating power in less than ten minutes.
- The LM6000s use water injection for NOx, control that enables the plant to easily meet guaranteed NOx emissions. The plant also features a continuous emissions monitoring system to monitor NOx and O2 emissions.
Fuel and T&D
Figure 4. Five LM6000 units were operational in July 2000
Natural gas is supplied to the power plant via the Trunkline Pipeline. Construction of the two-mile gas pipeline infrastructure at Shelby County was undertaken by another Reliant Energy affiliate, Reliant Energy Pipeline Services (REPS), which provides comprehensive pipeline infrastructure solutions to industrial and govornmental entities that need expertise to manage their pipeline infrastructure.
The pipeline was completed in less than six months including design, permitting, construction and testing. With its extensive experience with turbine-driven compression equipment, REPS was also selected to provide scheduled operation and maintenenace services to the LM6000 units at the Shelby County facility.
Ameren connects the project to the Ameren electricity grid via an existing 138 kV transmission line. The eastern boundary of Reliant Energy Shelby County facility fronts the Ameren substation, with 345 kV, 138 kV and 69 kV circuits.
The plant was successful in dispatching 200 MW of electricity to the Ameren grid during the summer of 2000. Three additional LM6000PC models are expected to be on line at the Reliant Energy Shelby County site by the summer of 2001, bringing the plant to a total capacity of 340 MW. During that time, Reliant Energy continued its strong ties to the surrounding communities of Neoga and Lake Mattoon. Reliant Energy is continuing to assess various types of support for local area projects, and has offered its assistance to various schools and civic groups.