Going Full Circle to Cogeneration: Manhattan's New Yorker Hotel returns to cogeneration system after more than 30 years

Diesel Progress North American Edition, Nov, 2001 by Brent Haight

When the New Yorker Hotel opened its doors in the early 1930s, it was the premier cogeneration facility in the world. Four uniflow steam--engine generators and a 530 hp De La Vergne diesel locomotive engine provided d.c. power for 2500 rooms and the exhaust was used to provide hot water heating and radiant heating to keep the hotel warm in the winter. While there were a handful of other facilities using cogeneration at that time, the New Yorker Hotel was the biggest.

The hotel supplied its own power until 1967, when economics dictated that purchasing electricity was cheaper than repairs to an antiquated system.

Now, after major renovations and upgrades, the New Yorker Hotel has returned to cogeneration. Rising energy costs helped prompt the New Yorker to install four Hess Microgen packaged natural gas-fired cogeneration systems totaling 600 kW of generating power.

"We are filling two roles in the New Yorker Hotel," said Steve Vandenberg, manager of business development at Hess Microgen. "We serve a portion of the base electric load and the thermal loads. We provide the domestic hot water and the preheating for the space-heating boiler. We are not doing peak power here. In order to make the best use of the equipment, we run the unit as much as we can. In order to do that, we've put in the multiple packages so we can switch them on and off in a stair step fashion. This assures that we are able to run them near their rated load basically all the time."

The New Yorker Hotel utilizes two 200 kW Hess 2001 cogeneration inductive generators, two 100 kW Hess 1001 cogeneration inductive generators, three Alpha Laval M6 plate and frame heat exchangers, three Bell & Gosset series 90 pumps and Square D reverse-acting slow trip breakers. The generators are directly coupled to each engine in a relatively small, prepackaged enclosure. The engines use the generator for initial startup, eliminating the need for batteries, starters and governors.

The hot water from the cogen units is distributed through piping to the plate and frame heat exchangers. The heat exchangers then transfer the heat to numerous hot water tanks that provide domestic hot water, laundry hot water and kitchen hot water.

The two 200 kW units each utilize Daewoo natural gas engines. The 100 kW units use Ford industrial natural gas engines. The engines are cooled by piping 50[degrees]F domestic water from a 50,000-gal. storage tank to a plate and frame heat exchanger. The engine's coolant loop transfers the required heat to the storage tank.

"We use the plate and frame heat exchangers to provide supplemental heating for the domestic hot water system," said Vandenberg. "We use the heat from the engine jacket cooling, lube oil cooler and an exhaust gas heat exchanger to preheat the water that feeds the boilers and also to provide the domestic hot water."

The New Yorker Hotel uses on-site power that is supplemented by grid power. Because of ConEd requirements, only induction generators can be used within the five boroughs of New York.

"The Hess units are operating in parallel with the grid," said Vandenberg. "If the units were taken off-line, it would be a seamless change to total grid power. The hotel remains connected to ConEd at all times. ConEd is always supplying electricity The system does not export power to the grid. We only put enough units in to pick up the hotel's baseload. The purpose of this installation is to reduce energy costs for the hotel through the efficiencies of cogeneration.

According to Vandenberg, the units run on a 21-hours-per-day schedule. The hot water load tails off for three hours each day. In the winter, the 600 kW system accounts for 80 percent of the hotel's electrical needs and 90 percent of its hot water requirements. In the summer, the system provides 50 percent of the electric need and 90 percent of the hot water demand.

"We get a strong load all day long," said Joseph Kinney, chief engineer at the New Yorker Hotel. "The laundry is going strong all day and the rooms use hot water in the morning and evening. We have tanks on the 25th, 35th and 44th floors so we step down the pressures. We have different heat exchangers for the different pressure levels. The pumps circulate the water to each tank. We are getting something in the neighborhood of 30[degrees] of useful heat from this water. It starts at about 205 [degrees]F and comes back at about 175[degrees].

"The infrastructure and the space, the physical space, is what facilitated the installation of cogeneration now," added Kinney. "The way I see it, we are going full circle. We are returning to how things were. We put boilers in the boiler room and generators in the generator room. It was a good plan in the beginning and it's a good plan now."

The cogeneration units tie into the buildings existing exhaust system. The same exhaust that is used for the hotel's boilers is used for the gen-sets.

As part of its arrangement with the New Yorker Hotel, Hess Microgen installed two 350 kW Daewoo emergency diesel generator sets.