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Oregon State’s Energy Center cogen handles 50% of electricity needs

Oregon State’s Energy Center cogen handles 50% of electricity needs

CORVALLIS, ORE. — Oregon State University’s new Energy Center, which contains a cogeneration facility that combines heating and electricity generation, allowing OSU to generate approximately half of its electric needs, recently received U.S. Green Building Council Platinum LEED certification.

The cogeneration system, which is calculated to lower the university’s energy costs by approximately $650,000 a year, has a maximum generation capacity of 6.5MW, and is expected to reduce CO2 emissions by 38% relative to the old plant. The cogen plant provides a reliable, cost-effective and efficient source of power, to partially offset the University’s electrical power demand from the utility.

In addition to housing a cogen plant, the Energy Center is a learning lab in which students mine data from the center and run simulations to learn how energy production works, as well as conduct other projects related to engineering and environmental sciences, including testing alternative bio-energy sources.

The new 27,000-sq.ft. Energy Center replaced the original heat plant, built in 1923, that had failing boilers and seismic issues. Before the campus switched over to the cogen plant, there were frequent mechanical problems that would disrupt campus-wide heating services.

“Comparing our old steam plant with the new energy center is like contrasting 1880s steam boiler technology to a jet-engine turbine,” said OSU Development Manager Henry Alaman. “There is a huge technological jump between the two and we wanted to give our staff all the tools to fully understand their new environment.

“When we first looked at this project we set high standards,” added Alaman. “We had never done a Platinum project on campus. We wanted to go cogen. The LEED decision was made early on, and it worked out pretty well for us.”

Cogen plant

The plant employs a dual-fuel 5.5MW combustion turbine generator (CTG) by Solar Turbines with a heat recovery steam generator (HRSG) by Rentech, and a 1.0MW steam turbine generator (STG) by Eliott.

The CTG generates power to export to the utility, and the HRSG uses the heated turbine exhaust to generate steam for the campus. The 1.0MW STG reduces the high pressure steam output of the HRSG to low pressure steam for the campus, and additional power for export is created. There are also two auxiliary boilers by English Boiler and Tube, delivering extra steam generation capacity in the winter to meet peak steam demand. For times when the CTG and HRSG are not operating, the boilers will also be a backup steam source.

The primary fuel for the cogen plant is natural gas, and all the equipment is able to run on fuel oil, diesel and biodiesel. Having the ability to run on a variety of fuels affords the university flexibility in choosing the lowest-cost fuel as market conditions change.

“The turbine can run on pretty much anything,” said Geoff Wampler, commissioning agent at Heery Intl. “That is why they went that direction ... as bio-fuels become locally available they plan on using them. The boilers run on natural gas, fuel oil, diesel or biodiesel.”

JH Kelly of Longview, Wash., the project’s mechanical contractor, used 3-D modeling to eliminate problems and expedite prefabrication of the cogen plant piping.

“3-D modeling for space management is a very valuable tool in a project like this,” said Dylan Toomey, field project manager at JH Kelly. “We fabricated over 75% of the piping installed, which was successful due to the accuracy of our modeling process.”

However, there were still some challenges regarding piping logistics.

“The building was built before any of the equipment or piping was on site,” explained Toomey. “This made the equipment and piping logistics complicated because the building was built as a shell and not as a structure that could be utilized for rigging and lifting.

“Overcoming the challenges required a lot of communication between ourselves, the general contractor, the engineers and the vendors,” continued Toomey. “We held weekly coordination meetings which encompassed space management, coordination between trades and design issues. These meetings had the engineers, general contractor, owner and all trades present.”

Other sustainable features

Larrie Easterly, the university’s engineering manager, said there is a laundry list of features that helped the building gain Platinum LEED status, including a rainwater harvesting system that is used for the boilers, radiant heating, hot water generated by heat recovery from the steam system, and natural lighting and ventilation, plus, building energy use is 52% better than the Oregon building code.

“I’ve worked on this project since day one, which is almost eight years ago,” Easterly said, “and it’s really nice to see something that a lot of people have worked on finally being completed. It’s not often that facilities staff gets to work on a building made for themselves.”

“The rainwater collection system was designed to be used as makeup water for the main process water,” said Toomey. “The system essentially consisted of an underground precast concrete collection vault, a rainwater filter and a few control valves at the storage tank. Installing this system took a few weeks.”

Another unique feature of the building is it utilizes waste heat from the power and steam generation process to provide heat to the office areas, conference room, and support spaces, and natural ventilation is used for cooling of the plant areas.

“Waste heat from the generation process is run through a heat exchanger, and then they use radiant flooring throughout the office conference room, restrooms and storage rooms in the building,” explained Wampler.

Alliant Systems, Beaverton, Ore., oversaw the in-floor radiant design and installation, using Wirsbo/Uponor radiant heating components.

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