Some of North America’s premiere zoos also happen to be places where distributed energy technology is making inroads.

By Peter Hildebrandt

Omaha’s Henry Doorly Zoo was among the earliest to apply hydrogen fuel cell technology. But now zoos in Los Angeles and the Bronx in New York City are following suit with their own fuel-cell technology. Since zoos have a great concern for the environment, and recreating the natural environment of animals does not include the sound of a noisy generator, the fuel cell is a good fit, because it’s quiet and clean energy.

It’s a Jungle Out There
Omaha’s Henry Doorly Zoo has the world’s largest indoor rainforest. The Lied Jungle has 123,000 square feet of floor space, and is 80 feet tall (about the same as an eight-story building)

Visitors can journey through three different rainforest habitats from Asia, Africa, and South America and see lush vegetation and animals native to those areas, along with seven large waterfalls, cliffs and caves, giant trees, and medicinal plants. The Lied Jungle’s roof is constructed of fiberglass-reinforced plastic and provides natural sunlight to penetrate the rainforest and generate growth.

While the zoo has been working hard at recreating the jungle environment, the Omaha Public Power District (OPPD) has been studying the use of a fuel-cell system it installed at the Henry Doorly Zoo’s Lied Jungle. The fuel cell was initially installed in spring of 2001 as part of a two-year test into the use of distributed generation, which was then and remains today a growing industry trend.

The test was designed to provide OPPD more experience with fuel cells in terms of their capabilities, their operation and maintenance, and the potential benefits as well as problems that customers could experience. The OPPD was later able to extend the project.

“The zoo was chosen to participate for several reasons,” says Michael Jones, OPPD corporate communications spokesman. “Among the reasons are that the Lied Jungle has what we considered a good 24-hour load factor requiring a substantial amount of electricity. Its proximity to OPPD also made it accessible to district employees who would be responsible for maintaining the unit. Equally important was that over the years OPPD and the zoo have maintained a very healthy working relationship.”

It was also determined that the zoo would be a good partner because the project could provide a number of benefits to the zoo. Among them would be electricity from a new 200-kW fuel cell, replacing two 60-kW cogeneration units the zoo removed because of high maintenance costs. The agreement also provided that the zoo would only be charged for the electricity it consumed while OPPD would continue to own, operate, and maintain the unit. In addition to servicing the electrical needs of the jungle, the zoo was also able to use the unit’s heat-recovery system to preheat water for the facility’s domestic water system, temper water for its wildlife ponds, provide humidity, and provide hot water for the zoo’s restaurant.

The initial cost of the unit was $800,000. It was purchased from International Fuel Cells Inc., (now UTC Power, A United Technologies company), based in South Windsor, CT. The US Department of Energy (DOE) provided $200,000 of that amount in the form of a grant.

“When it comes to the question of why fuel cell technology was used, I think a big part of it is that earlier fuel cell technologies were seen as a growing industry trend,” adds Jones. “Rather than using combustion, fuel cells produce electricity chemically, and, because there is no combustion, fuel cells are virtually emission-free. The OPPD felt it was important to conduct practical research into that area to gain more experience, especially if we decide to start installing them for customers in the future. This especially applies to customers interested in backup power or an uninterruptible power system. Again, this was an opportunity to learn more about their operation, about maintaining such units and about their capabilities.

“We cannot speak for the zoo as to how well the unit has worked for them. But clearly, we have been pleased and have learned much. I think the fact that the unit continues to operate also says a great deal. The unit has so far performed as well if not better than expected in terms of efficiency and reliability.”

In the last three years, the zoo’s fuel-cell system has had an availability of 95%, meaning very few outages, according to Jones. If there is a downside, it would be the cost.

Earlier this year, the OPPD estimated that it costs about 15 cents to produce a kilowatt-hour of electricity through a hydrogen fuel cell, compared with as little as two cents per kilowatt hour from coal-fired units. In order to reduce some of those costs, Congress has begun exploring possible tax credits and other efforts.

Other challenges when it comes to fuel-cell technology include maintenance, such as replacement parts and various equipment, the inability to recapture and reuse all the heat generated, a lack of economy of scale (the costs here were unique to having one unit rather than being able to spread those costs over several units), and training the personnel needed to operate what is very sophisticated equipment.

“The only update that OPPD made actually occurred up front when the cell was initially installed,” says Jones. “We had to install a nitrogen scrubber in the natural-gas supply line. The reason is that sometimes the natural gas fed to this part of the country will contain a little too much nitro and will poison a fuel cell. When the OPPD examined and analyzed the chemical makeup of the natural gas that would be used in this fuel cell, they found indeed it exceeded the fuel cell specifications. As a result we installed the scrubber. Other than that, it has been a matter of routine maintenance and not additional modifications. We will continue to operate it for the foreseeable future.”

UTC Power’s database of information indicates that it’s run very well, according to Rob Roche, UTC Power marketing strategy manager for onsite power. It has accrued over 48,000 hours. The stack technology at the time of its installation had it designed for a 40,000 hour lifespan.

“UTC Power monitors all their products continuously, and we have historical data going back to the date this equipment was commissioned,” says Roche. “We can see on a daily basis how well the fuel cell has performed. Another interesting feature of Omaha’s installation is that they’ve elected to place the fuel cell on a dedicated circuit. This is a testament to the reliability of that fuel cell since 2000 and its ability to support loads on its own back without any dependence on the power grid.”

The Omaha unit runs between 60 kW at night and as high as 160 kW during the day, a fairly wide range of operation. “This unit does very well in following loads,” adds Joe Staniunas, veteran UTC Power engineer. “We’re working hard to improve the economics of running fuel cells.

“We have a large development program under way right now that is expanding the capacity of fuel-cell technology from 200 kilowatts to 400 kilowatts. In doing so, we’re driving the cost down on a dollar-per-kilowatt basis, and we’re also extending the life of the stack itself, from some five to 10 years, which from a life cycle economic standpoint adds a lot of value back to the customers. We’re really attacking first cost and life cycle maintenance cost very aggressively.”

The Lion’s Share of New DE
In its old life, the “Lion House,” built in 1903 at the Bronx Zoo, housed cages of animals on display. The 20,000-square-foot building was the largest of the zoo’s early 20th century Astor Court, but it has been closed to visitors for more than two decades.

After an extensive remodel, the Lion House is slated to come up for use in June 2008. The building has won the NYC Green Building Award for, among other things, its geothermal system output—which is balanced with a fuel cell—as well as the zoo’s cogeneration plant and condensate waste heat in a computerized energy-conserving protocol.

Sometime prior to the official opening of the exhibit, the fuel cell will be activated. The connection process is taking place between fall 2007 and June 2008, when the zoo’s new season begins. As of 2007 the building itself was over 80% complete. Many of the exhibits have been completed, and various building systems are substantially completed but must be turned on and commissioned.

The Bronx Zoo currently has a cogen plant operating using diesel generators. Power is generated and the waste heat is distributed throughout the zoo. The cogen installation has been running for more than a decade. The zoo parallels with Consolidated Edison Inc., meaning it has the utility grid as a backup source of power should it lose its plant for any reason. But on a normal day-to-day basis, it uses the cogen energy source and does not have to use the grid.

“The Bronx Zoo has been very much behind sustainable design in their energy use,” says Rick Meilan, professional engineer with Kallen and Lemelson Consulting Engineers LLP. “They’re happy to have a redundant system from Con Edison.”

The Lion House where the fuel cell is located is at the fringe of the developed portion of the campus. North and west of it there is no development. Despite the name, strongly hinting at a center for African carnivores, the building will house chiefly animal species from Madagascar—including lemurs—and a number of Nile River crocodiles.

K&L Engineers have also designed another building, the new Global Conservation Center (GCC), which the zoo is installing in the adjacent corner of the zoo. The GCC will be completely separate from the grid, as it is in an even more remote area of the zoo. There were options to support it from Con Edison or from the cogen power plant. But the final decision on powering that site was to go with microturbines on a standalone basis. These microturbines spin very quickly to generate electricity and use natural gas to create the energy to spin them. The waste heat coming off the microturbines is used for cooling and heat needs at the zoo as well. A natural-gas pipeline had to be extended to provide for the GCC. The fuel-cell system at the Lion House also uses natural gas.

The electrical distribution grid that existed when the Lion House building was being designed did not have adequate capacity in the corner of the campus where work was being done to support the renovation of the building. Engineers were faced with options for dealing with this problem. One of their options was to upgrade the grid, the underground distribution in that corner of the campus, by providing more power from the cogeneration plant which is located all the way at the southeast end of the campus.

The Lion House site is being renovated under funding from New York City’s Department of Design and Construction. The architectural team is working for the DDC directly under the city’s high-performance building program. “All those factors pushed this to become a high-performance building, and the fuel cell worked well with that whole philosophy,” says Meilan.

The New York Power Authority (NYPA) was very involved with the project as well. One of the things put on the table during discussions was the fuel-cell option. “The suggestion probably came from the NYPA,” adds Meilan. “We explored that option and then proceeded with it. The NYPA was instrumental in this regard in that they pursued getting grants both from the federal DOE and the New York State Electric Research and Development Agency (NYSERDA) to help support this fuel cell. “The NYPA provided the fuel cell and we are interfacing with it and using it. Therefore, the purchase, delivery and installation of the fuel cell is being done by the NYPA, not by the building contractors.”

The fuel cell has worked very well from the standpoint of sustainability and in providing a local power source, a local source of waste heat which is being used thoroughly in the building and integrated with other sources of waste heat available on the campus from the cogen plant. This was not an easy installation, according to Meilan. The location of this building on the campus is such that it is in a highly visible location, so placing equipment outside the building was simply not feasible.

“A fuel cell normally is located outdoors, sitting on the site and making it the easiest to install and maintain in the future,” says Meilan. “But in this case the installation had to be placed indoors—definitely a challenge and remaining one at this point in the finishing up of construction.”

Fuel cells typically have a large footprint. The challenge comes in being certain you have enough space for it as well as providing adequate ventilation for it. There is a potential for ozone leakage from a fuel cell; therefore, the exhaust system must function with the operation of the fuel cell. If the waste heat is not being used it must discharge heat somehow, through a remote cooling system. Various aspects become issues when the fuel cell is indoors instead of outdoors.

Future issues arise as well. A path must be maintained for pulling the fuel cell out for maintenance work. The fuel cell must be readily removable and in a location where it can be accessed from above; the design for future events are such that it might be pulled out to a location outdoors so that replacement of the stacks are able to be done periodically.

The NYPA is the state’s utility and a public entity, operating some 18 generating facilities across New York. It has been promoting distributed generation, either through photovoltaics, fuel cells, microturbines, and other technologies for the benefit of their customers since the early 1990s. The fuel cell at the Bronx Zoo is quite similar to one installed in New York’s Central Park back in the mid-1990s to support the Central Park Police Precinct, as well as one at another Wildlife Conservation Society site, the New York Aquarium at Brooklyn’s Coney Island.

“At around the time of the decision-making on the Bronx Zoo fuel cell, we had also recently installed a fuel cell at the New York Aquarium with the NYPA, which greatly contributed to our decision to try one at the Lion House,” says Susan A. Chin, AIA director of planning and design for the Wildlife Conservation Society/Bronx Zoo.

Photo: Wildlife Conservation Society

The Bronx Zoo’s Lion House has won the NYC Green Building Award for its geothermal system output, which is balanced with a fuel cell.

“NYPA has been doing this a long time, and we’re very pleased to see our customers are inquiring about this technology; and other people in government at a whole host of levels now more than ever appreciate the economical and environmental advantages of distributed generation for their facilities,” says Brian Warner, director of policy analysis and external communications.

Michael Nash, NYPA engineering manager in energy services and his group are responsible for the installation of distributed generation for the NYPA, the Bronx Zoo fuel cell being just one of a number of projects. “The NYPA provides energy-efficiency services and promotes clean energy technologies with all of its customers and at all government facilities throughout New York,” says Nash. The NYPA has installed 14 fuel cells throughout New York State. The bulk of those fuel cells are located in and around New York City, supporting the city’s wastewater treatment facilities. The power at nine of those treatment facilities is supplemented by fuel cells that operate on anaerobic digester gas (their installation in Yonkers-Westchester County is the first ADG fuel-cell facility in the US).

The fuel cell arrives for installation at the Bronx Zoo’s newly refurbished Lion House.

“The Bronx Zoo is one of our customers. We became aware of the zoo’s plans to renovate the Lion House and learned that their electric distribution system was nearly fully loaded in the general area of the Lion House. The Bronx Zoo was concerned about emissions and noise and their effects on the animals and the public areas. We recognized that local generation could provide needed reinforcement of their system and proposed a fuel cell since it is the cleanest and quietest source of heat and power, along with being highly reliable.”

An added benefit was the supplying of supplemental heat energy. In addition the fuel cell will add four points to the renovated Lion House’s Leadership in Energy and Environmental Design (LEED) rating (the Green Building Council’s award for leadership in energy and environmental design), something the Bronx Zoo was very interested in.

The fuel cell is located in the basement of the remodeled Lion House. It had to be rigged into the basement during renovation construction. The window for doing this was July 2006. The fuel cell remained in storage in-place until renovation work reached the point that final connections could be made. The NYPA is remobilizing to make those hookups now.

“We plan to commission it in early 2008,” Nash says. “The unit is not yet operating but will provide local electric reinforcement and supplemental heat for the new Lion House.”

As far as other DE installations at the zoo, the facility has a central, 3.8-MW combined heat and power plant. The new fuel cell is a phosphoric acid fuel cell manufactured by UTC Power. When placed in operation, it will generate 200 kW of electricity and supply 700,000 Btus of heat.

The total energy project cost is $1.5 million, which is being offset by $140,000 and $584,030 in DOE funding and a grant from NYSERDA. According to the NYC Department of Design and Construction, the total annual energy cost is projected to be 57% less than a code-compliant building. Annual energy cost savings equal $140,000. The simple payback is 6.3 years.

UTC Power installs fuel cells, but in this particular case a different vendor did the installation with UTC Power providing the technical advice and support. Installers do this work while UTC Power advises them on requirements to meet the company’s standards. “Our technicians will do the commissioning, which takes place January, 2008,” adds George Angelescu, UTC Power project manager on the Bronx Zoo project. “This is a grid-connected unit in the basement of a building in a very congested area. There will be a remote monitoring system for 24-and-seven monitoring. If there are any shutdowns, we will have service technicians from the other sites travel to this location immediately. The remote monitoring system will send a technician to the site automatically from one of the many other New York locations that we have.

“All the technicians involved in servicing will be trained by us for a number of days, including a course taught to anyone involved with this fuel cell. For false alarms, the system can even be restarted remotely.”

“A zoo is an especially good place to educate the public, as well as feel a connectedness to the globe’s natural environment,” says Roche. “The fuel cell, a clean energy source, is a great fit. It’s low in noise; the Madagascar wildlife will be right above it in the Lion House, and if you’re trying to think of a zoo as a place for appreciation and education about the world on a macro-level, then why not combine clean, new energy in a zoo setting? Zoos have a demand for diverse climates for varied species—cold, hot and subtropical—as well as the need for copious amounts of water needed for cleaning.

“I just think this is a good combination for new energy and clean energy at a place with both high-energy demands and needed reliable power. Redundant power such as clean technology in the form of a fuel cell seems very fitting. In a hospital or hotel there is not as much of the general public going through; those other sites don’t afford the same grassroots opportunities to educate the public about what we’re doing as a zoo does. They’re unique in that respect. I see the fuel cell in the future as being more a part of the educational landscape at such sites as zoos. A big part of building our industry is education. This is a multigenerational educational opportunity.”

There is also the possibility of using animal waste in future years for a duel fueling of the fuel cell with pipeline natural gas, supplemented by waste gas from the zoo’s buildup of organic matter. 

Peter Hildebrandt is a writer specializing in science and engineering topics.

DE - January/February 2008