Betting on Power at Casino Morongo
The new casino on Interstate 15 heading toward Palm Springs, CA, rises from the desert like a neon monolith set in an oasis. The $250-million Casino Morongo, built by the Morongo Band of Mission Indians to replace their two-story, traditional-looking boxy casino, delivers spectacularly on the image of Las Vegas casinos.
Enter via a winding driveway, park in a large sprawling garage, and walk a few steps into a vast circular space filled with bank upon bank of flashing, musical machines that will satisfy the cravings of any gambler. Four restaurants snuggle into the back reaches of the room. A hotel rises in the 27 floors above.
The visitor will see no utility distribution poles in the nearby landscape. All this sound and light (and heating and cooling) is powered by an 8-MW cogeneration plant tucked back behind the large parking structure.
Headquartered in Banning, 20 miles west of Palm Springs and 90 minutes east of Los Angeles, the 32,000-acre Morongo Band reservation was established in 1865 and is home to about 400 tribal members.
Tom Linton, the Morongo Band’s director of planning and economic development, said cogeneration is an environmentally friendly technology and gives the tribe a reliable source of energy. Being completely independent of the state’s electrical grid serves its interest in self-sufficiency, he says. “And it means that our power supply is not at risk from rolling blackouts or some of the other impacts from heavy usage in other parts of the state.”
Practical reasons also drove the decision. The Morongo Band’s first casino experienced low-voltage outages on a regular basis. Furthermore, by being independent of the utility grid, the tribe avoids the expense of paying for utility infrastructure to connect the new casino to the utility’s distribution system. The new building also avoided departed-load charges by never having taken service from Southern California Edison.
Furthermore, the tribe wants to diversify its assets and not rely solely on gambling income. The original casino was built in 1983 and became one of the largest Indian government gaming facilities in California. The proceeds from that casino allowed the tribe to build the new casino as well as create other business opportunities.
The tribe built a $26-million water bottling plant in 2003 after purchasing spring water rights for $3 million from a local water district. Arrowhead Mountain Spring Water operates the plant. A 3-MW cogeneration plant was later added to provide adequate power. In addition, the tribe constructed their own wastewater treatment plant to serve the casino.
By 2003, the Morongo organization was the largest employer in the San Gorgonio Pass, with over 1,500 employees, including 200 at the water bottling plant.
In line with this philosophy of independence and diversity, leaders of the Morongo Band knew when they hired EMCOR Energy & Technologies---a unit of EMCOR Group Inc., headquartered in Norwalk, CT---that they wanted a cogeneration plant to be grid-independent and they wanted it to be in commercial operation within 12 months---in time for the Casino opening in November 2004. EMCOR did indeed meet the deadline. The final tab for the plant and the heating and cooling system: $16 million.
Working quickly, the two sides signed a letter of intent in four weeks. Equipment was ordered three weeks after that. The final design/build contract ensured that EMCOR would operate the plant for 10 years once it was in operation. This influenced the design/build plan, says David Holden, EMCOR’s regional director in the Anaheim, CA, office. “If I build for the owner, I’m contractually bound to make the plant work on day one. But knowing I have to live with what I build for the next 10 years, I have no incentive to go low-cost, because it will haunt me as an operator.”
Knowing that, Holden said his choices included adding such things as redundant pumps, and choosing to invest in the brand of controls he is comfortable with rather than the lowest-cost control system.
The technical requirements dictating the design elements for off-grid operation included generation redundancy, fuel redundancy, and temporary construction power. Holden described the design parameters. The peak electrical load for the 28-story hotel tower, casino, and spa complex was estimated at 4.62 MW; the minimum electrical load was estimated at 3 MW, with an average load of 3.62 MW; and the new cooling system must have chilled water capacity of 3,600 tons with a 2,400-ton peak load.
Allowing for 15% future load growth, the design team knew the casino complex would need at least 5.3 MW. Furthermore, the facility required a minimum addition of 6 MW of diesel-fired generation to back up the gas-fired generators. “Everything you’re doing with an unbuilt facility is a guess,” says Holden. We didn’t have historical energy use to build from, only rules of thumb.”
EMCOR rejected combustion turbines because, first, there was no requirement for steam. When thermal loads are low, a combustion turbine becomes less efficient and the thermal uncertainty made it difficult to go with turbines, Holden says. Even the casino’s electrical profile would create difficulty for turbines. Loads can go as low as 2.5 MW on cold nights, with a minimum number of people in the facility. The small off-peak load also made sizing a redundant system pretty tough.
EMCOR also looked into wheeling power to the wastewater plant three miles away, but economically it didn’t pencil out, Holden says.
After engineers evaluated GE Jenbacher, Caterpillar, and Cummins engines, they decided on four gas-fired 2-MW Caterpillar G3520C engines, to serve as the main power system, and three diesel-fired 2-MW Caterpillar 3516B engines for the backup system. The gas-fired Caterpillar has a rated efficiency of 38.2%, a 7,000 MBtu/hr recoverable heat rate, and a NOx rating of 1 gram/brake horsepower/hour. Emissions are fully controlled to meet South Coast Air Quality Management District emission standards, reducing NOx emissions to 0.15 gm/bhp/hr using selective catalytic reduction equipment.
Cooling is provided by one 1,100-ton Broad absorption chiller and two York centrifugal chillers, each with 1,250-ton output. Domestic hot water---supplied to four restaurants and a food court in the casino---and the hydronic heating system for the casino are heated using waste heat run through a loop from the engines through the waste-heat boiler. Jacket water is at 198°F and exits the heat recovery exhaust at 210°F. Gas-fired hot-water boilers serve as back-up. Hotel rooms are heated electrically.
The waste heat is distributed based on economic priorities, says Holden. The first priority is to displace the owner’s use of natural gas. Given that the efficiency of the heat exchanger is higher than the efficiency of the absorption chiller, the waste heat is directed first to the building’s heating system, it then heats domestic hot water, and it is then directed to the absorption chiller. Cooling provided by the absorption chiller has priority over the cooling produced by the electric chillers.
These economics contrast with those of a cogeneration system interconnected to the grid system, Holden says. That system’s first priority is to reduce the owner’s peak-demand charges and energy charges administered by the utility.
Holden says all 8 MW of gas generation and 6 MW of diesel generation are on the same electrical bus. If the generators go off-line, emergency loads are restarted within 10 seconds and the backup diesel system will come online within 20 to 30 seconds.
EMCOR Energy & Technologies relied on EMCOR Group’s operating companies for most of its subcontracts, making project execution very easy, Holden says. EMCOR companies Dynalectric built the electrical systems and University Marelich Mechanical served as mechanical engineers. Syska & Hennessy Inc. completed the detailed designs.
Another advantage for both EMCOR and the tribe was the ability to integrate the design of the facility into the casino’s construction, unlike most cogeneration projects added to already-built facilities. Savings were created, for example, because it meant one less chiller was needed and the cooling tower, already designed, simply was upgraded to accommodate the cogeneration plant in addition to the chillers.
EMCOR had to perform one other task independent of but integral to building the cogeneration system. The lack of utility electrical distribution to the site meant the company had to supply power during the construction phase using temporary diesel engines. Once the permanent backup diesels were installed, they supplied power until the main gas engines were commissioned. The company also had to provide 600 tons of cooling once the casino began being closed in. They used the owner’s diesel engines to power an electrical chiller.
Since its November commissioning, the cogeneration plant has performed flawlessly. During a hot, 90°F weekday visit in early July, the system was generating just over 4 MW. The casino was cool and brightly lit, folks were keeping the slot machines singing, and, in the restaurants, the food was hot. It is doubtful anyone but the plant’s staff and casino owners know Southern California Edison is not delivering power.
Author's Bio: California-based Lyn Corum is a technical writer specializing in energy topics.