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Class of 2007/2008

Mint Farm Energy Center

Longview, Wash Wayzata Investment Partners

Good instincts, big chips, steely nerves are table stakes in powerplant poker

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t's not easy to make a buck in the electric power business as a merchant producer. Success demands industry savvy, a reliable generating facility in a good location, access to cash, file cabinet's worth of regulatory approvals/permits, good fuel and electric sales contracts, top management and O&M personnel, and some good oldfashioned luck--among other things. Wayzata Investment Partners has had some anxious moments since it went "all in" on a mothballed 311-MW (nominal) 1 × 1 combined cycle in Longview, Wash, pushing $27-million into the center of the table in bankruptcy court, but Mint Farm Energy Center Project Director

PACESETTING PLANTS, Class of 2007/2008

Scott Magie says he never ment of many types of comdoubted that the project panies around the globe. The was a winner. company currently manages Magie is the team memabout $6 billion in a wide ber with good industry range of investments. Havinstincts. He honed his ing the chip rack to fund purdiverse skills at the coalchases such as Mint Farm fired Allen S King Generatfacilitates transactions and ing Station, Prairie Island management. Magie Nuclear Generating Plant, Mint Farm (Fig 1, above) and Northern States Power Co's nat- has some striking similarities to ural-gas and unregulated generation Associated Electric Cooperative Inc's subsidiary NRG Energy Inc before Dell Power Plant project featured striking out on his own seven years elsewhere in this issue. The Longview ago as a consultant to investment plant posed greater challenges for its organizations and utilities. owners primarily because it was in Wayzata's strength is reflected mothballs about a year longer than by its long-term investment experi- Dell, construction was only about ence in the purchase and manage- one-third complete instead of two35

2, 3. Large components yet to be installed were laid up outdoors under protective covers (left). Smaller items (right) were stored in a temperature/humidity-controlled space (right) thirds, and the Washington site is far more constrained than the one in Arkansas. A major benefit: Equipment was extremely well maintained and cataloged. The Mint Farm odyssey began 10 years ago when the sleepy Washington Water Power Co of Spokane transformed itself into Avista Corp. Its charter included the development and/or purchase of power-generation and gas-storage facilities, under the banner of Avista Power, to support the remade company's energy marketing activities with physical assets (unlike the Enron model). A 1999 agreement with STEAG

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AG, Germany's largest independent power producer, formed Avista STEAG LLC to pursue both new plant construction and the purchase of existing generating plants in the West. Mint Farm was one of the first projects the new partnership pursued and licensed. Financial pressures forced the deactivation of Avista Power in 2001 and the STEAG partnership was dissolved late that year. Atlantabased Mirant Corp bought the project and began construction. It mothballed Mint Farm in 2002, a fallout of the Enron debacle that soured investors on energy-trading firms.

These actions speak volumes about an industry that had been valued for its decades-long stability. When Wayzata took possession in late December 2005, Mint Farm had been laid up for just over three years. It took another two years to achieve commercial operation (Dec 17, 2007). Magie estimates that about 35% of the equipment was in place and that about 90% had been ordered when Wayzata moved in; most of the equipment that had to be installed was stored onsite (Figs 2, 3). He graded the quality of the layup an A-minus. Magie spent several months after

COMBINED CYCLE JOURNAL, Fourth Quarter 2007

financial close to sort through everything regarding air permits, interconnection agreements, equipment contracts, etc. Mint Farm hired a power marketer to help firm up gas and electric-sales contracts. Subsequently, it negotiated a long-term service agreement with GE Energy, Atlanta, for the 7FA+e (Model 7241) gas turbine (GT). This machine is gas-only and equipped for steam augmentation; it has a Mark V control system. Magie went with a GE LTSA because he wanted to mitigate GT risk to the extent possible. The 16-person, contracted GE O&M staff--including Plant Manager Chetan Chauhan, O&M Manager Robert Marsh, and Plant Engineer Rob Liner--already was challenged by having to deal with many expired equipment and performance guarantees. To illustrate: Fuji Electric Corp of America would not renew guarantees for its Series KN (two-cylinder unit; one HP/IP, one double-flow LP) 133-MW steam turbine (ST)/generator which was still in the original shipping crates. Control system for the steamer was provided by Fuji under a Siemens license. Both the gas and steam turbines are equipped with hydrogen-cooled generators. The duct-fired, triple-pressure heat-recovery steam generator was supplied by Foster Wheeler EnerPACESETTING PLANTS, Class of 2007/2008

gy Corp, Clinton, NJ. It John Walsh joined the team is equipped with an SCR in late 2006, soon after conthat uses a 17% solution of struction was restarted. aqueous ammonia as the Mint Farm is located 10 reagent. NO x emissions ft above sea level close to the are maintained at or below banks of the Columbia Rivthe 2.5-ppm permit limit; er--outside the 100-yr flood ammonia slip is 10 ppm or plain but inside the 500-yr less (both 24-hr averages). flood plain. Approximately CO catalyst restricts emis1400 caissons were placed sions of that pollutant to 6 in the ground by the original Walsh ppm (one-hour average). EPC contractor to support Forney Corp, Carrollton, Tex, buildings and equipment. manufactured the 458-million-Btu/ Water typically comes from wells. hr duct burner for the HRSG, which Alternatively, river water can be is used only occasionally the way the accessed via a nearby Weyerhaeuser plant is operated today. Marley (now plant. The plant's NPDES (National SPX Cooling Technologies Inc, Over- Pollutant Discharge Elimination land Park, Kans) provided the five- System) permit allows Mint Farm to cell mechanical-draft cooling tower. discharge treated wastewater directHoltec International Inc, Marlton, ly to the Columbia but, instead, the NJ, manufactured the two-pass sur- power producer sends its coolingface condenser with stainless steel tower blowdown and other liquid distubes. Balance of plant controls came charges to Weyerhaeuser for treatfrom ABB Power Plant Automation. ment before being returned to the Magie's power-industry experience Columbia River. gave him the confidence to bypass When Kelly moved on the site, the typical EPC contractor option one of the first things it did was to to complete the plant. Instead Mint check GT alignment. A positive sign Farm hired J H Kelly, a Longview was that the machine, which could construction company with experi- operate at that time only on turning ence in powerplant and large indus- gear, was aligned within three onetrial work, as the general contractor. hundredths of an inch of perfection. Regional labor comprised the major This gave Magie confidence that the portion of the construction workforce. caissons and foundations were proTechnical Director/Project Manager viding the proper support. Alignment

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and 2006 and the number of "corrections" that had to be made prior to first startup. Magie and Walsh had to go back to key suppliers to locate this information, digest it, talk to other users about their experiences, and decide what was important, what was not. This is a time-consuming assignment. Tough to make informed decisions unless you have operated powerplants previously and have the practical knowledge to ask the right questions. To illustrate: Instrumentation, transmitters in particular, were outdated with respect to design and no longer under warranty. Rather than upgrade, Magie and Walsh concluded that it was more cost-effective to scrap many and buy the latest equipment. With regard to motors, they decided send about three-quarters of the plant's complement to an outside shop for inspection, cleanup, and bearing work--as necessary. Only one required a rewind and the root cause was not layup related. This protected Mint Farm against the motor failures experienced by Dell, which did not opt for wholesale shop overhaul. Pumps had been maintained very well during the layup and were fit for duty. Some valves were problematic and required maintenance. Switch-

4. Only the outside walls of the HRSG had been erected when construction was halted in September 2002 was adjusted and the unit grouted in place. Fig 4 shows the degree of completion of the GT and HRSG when construction was restarted. For the HRSG, only the outside walls had been erected prior to layup. They had been covered with plastic sheet and were in excellent condition; only blemish was some minor corrosion of structural carbon steel. Kelly completed the boiler with help from a Foster Wheeler technical advisor (Fig 5).

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One of the challenges, associated with buying a partially completed plant that had been in layup for years, Magie said, is that the facility stands still in time. Thus correspondence that routinely flows from the OEMs to their customers regarding operating experience, suggested upgrades, etc, rarely is available to the new owner. As for the volume of paperwork, just think of all the TILs (technical information letters) GE released for the 7FA between 2002

COMBINED CYCLE JOURNAL, Fourth Quarter 2007

5. Tube section is lowered into the HRSG by general contractor J H Kelly of Longview, Wash (left) 6. Large flat-screen monitors allow control-room operators to spot potential problems quickly (below)

gear had been stored in a heated building and was in excellent condition. The proverbial fly in the ointment at Mint Farm--actually there were two flies--surfaced in the Atlas Copco two-stage centrifugal gas compressors required for the GT to operate. First, the compressors were not properly laid up. Impellers were fine but the gearboxes were unfit for duty; possible cause was oil additive that never should have been used. There was no incentive to conduct a root-cause analysis. Next: During commissioning, one

PACESETTING PLANTS, Class of 2007/2008

of the compressors was knocked out of action by foreign object damage traced to improper cleaning of the intercooler. Thinking is that segments of fins blown loose during cleaning traveled downstream and did about $300,000 in damage. After this incident, strainers were installed at both inlets of each two-stage compressor. Perhaps the biggest surprise, one virtually impossible to identify during any due diligence effort, was that the plant electrical system was configured incorrectly in many respects. The nature of the errors

was such that the entire system had to be redesigned during construction. A special engineering team was mobilized for the extensive effort which set back startup by about two months. End notes. Mint Farm is not your typical merchant powerplant; rather, it resembles a utility station in several respects. One is the generous size of all buildings. By contrast, it also has some innovative features that you expect of an independent power facility--such as the control-room layout and extensive use of wide, flatscreen monitors (Fig 6). Magie was the "lead designer" for the control room. The original operator's desk, accompanying furniture, and CRTs had been shipped to other Mirant facilities after the decision was made to stop construction. Magie had seen enough cramped control rooms with monitors you could hardly see and welcomed the opportunity to create a more operator-friendly workspace from scratch--one similar to an energy trading floor. Game plan for Mint Farm was to complete punch-list items during the spring shutdown when it's tough for any type of plant except hydro and nuclear to sell power and to fine-tune performance before the summer run.

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