The NIH Central Utility Plant (CUP) houses five traditional gas- and oil-fired boilers that produce steam. Steam is needed for a myriad of NIH campus operations. These include space conditioning, hot water heating, medical equipment sterilization, autoclaves, animal cage and rack washing, dishwashing, and other process uses. The CUP generates and distributes ~ 1.2 billion pounds of steam per year to the NIH Bethesda campus buildings. The amount of electrical power the chiller plant consumed is 36 MW—enough to cool 30,000 single-family homes. There are over 300 manholes located around the campus that allow inspections and maintenance of the underground utilities. The electric cost to run just one chiller for one day is $8,300; to run all 12 for one day (required during the hottest summer days) is almost $100,000.
The plant distributes utilities to NIH’s buildings underground via
2 miles of walkable tunnels
2 miles of concrete trench
Natural gas lines totaling ~ 3.6 miles in length
Domestic water lines totaling ~ 12 miles in length
Steam and chilled water pipe lines totaling over 7 miles
Boiler PlantThe NIH Boiler Plant, part of the Central Utility Plant (CUP), houses five gas-fired boilers. Each year, the plant burns about 3 billion standard cubic feet of natural gas to generate about 1.8 billion pounds of steam for the buildings and facilities of the NIH Bethesda Campus. When necessary, the boilers can also be run on No. 2 fuel oil. Chiller PlantThe CUP’s twelve chillers consume about 165,000 megawatt hours (MWh) of electricity per year, roughly equivalent to the electrical energy required to air condition 100,000 Maryland households for a year. The total energy use (fuel and electricity) at NIH is equivalent to the energy used by 50,000 average Maryland homes. COGEN PlantCogeneration, or combined heat and power, is a process that uses waste heat from another system to generate two forms of useful energy (electrical and thermal) simultaneously. The NIH’s 23 megawatt cogeneration (COGEN) plant, in operation since July 2004, produces low-cost steam and electricity at high efficiency and with low emission levels. It is one of the largest U.S. government COGEN plants, and is one of the cleanest cogeneration systems in the world, producing 44% less emission than a similar, state-of-the-art plant built in 2012. The COGEN plant meets National Ambient Air Quality Standards more effectively and economically than traditional boiler systems, because thermal energy that would otherwise be wasted is captured for use at the on-site facility. About 30% of the energy generated by NIH's COGEN plant is converted to electricity, about 55% is used for steam generation, and the remaining energy (less than 15% of the total energy generated) is rejected to the atmosphere through a unique stack rising above the plant. Utilities DistributionUtilities are distributed to NIH buildings through underground walkable tunnels (2 miles), concrete trenches (2 miles), natural gas lines (3.6 miles), domestic water lines (12 miles) and steam and chilled water pipes (over 7 miles). There are over 300 manholes located around the campus, facilitating inspection and maintenance of the grounds utilities.
CUP Facts and Figures
|As of January, 2016
||11.8 million sq. ft.
||11.8 million sq. ft.|
|Number of units
||5 boilers, 1 cogeneration plant|
||Welded steel, schedule 80 with insulation
||Welded steel, schedule 80 with insulation|
|Piping trench length
|Cogeneration plant capacity
The Central Utility Plant (CUP) burns 3 billion standard cubic feet of natural gas per year to generate 1.8 billion pounds of steam and 190,000 megawatt hours (MWh) per year of electricity.
The amount of natural gas burned in the CUP in a year is equivalent to 26 million gallons of gasoline.
In addition, NIH purchases 300,000 MWh per year of electricity.
The total energy use (fuel and electricity) at NIH is equivalent to the energy used by 50,000 average Maryland homes.
The total electricity use by NIH, 490,000 MWh per year, is equivalent to the electricity use by 35,000 Maryland homes.
In order to meet NIH’s air conditioning needs, NIH operates a large chiller plant. The chiller plant peak electrical power requirement is 36 MW.
Annual power use is 165,000 MWh per year which is equivalent to the power used for air conditioning by more than 100,000 Maryland households.
What is Cogeneration?
Cogeneration (COGEN), also called combined heat and power (CHP), is the process whereby a single fuel source, such as natural gas, is used to produce both electrical and thermal energy. An onsite cogeneration system is more efficient than a utility-operated central power plant because thermal energy that would otherwise be wasted is captured for use at the onsite facility.
The NIH Cogeneration Plant
The NIH has one of the largest U.S. government cogeneration plants; it is also the cleanest cogeneration system in the world. The COGEN plant meets National Ambient Air Quality Standards more effectively and economically than through the use of traditional boiler systems.
The NIH COGEN plant has been in operation since July 2004. Housed at the plant is a 23 mega watt (MW) combustion ABB GT10 jet engine that was built in Sweden. It was selected because it produces less than half the nitrogen oxide (NOx) of other commercial turbines. The NIH COGEN plant has a waste heat-recovery steam generator (HRSG) that produces ~ 100,000 pounds of steam per hour. The combustor burns highly compressed natural gas at around 3,000°Fahrenheit (F) and generates a turbine speed of about 7,700 revolutions per minute. About 30% of the energy generated is converted to electricity, and 55% is converted to steam, which is generated in a boiler at a temperature of ~ 300°F. The remaining energy, which doesn’t exceed 15% of the total generated, is dispersed as waste through a unique stack rising above the plant.
COGEN provides ~ 40% of the NIH’s average annual steam load. It produces enough power for 18,000 homes or two of the engines of a fully loaded 400-ton Boeing 747 during cruising altitude. Cogeneration saves the NIH an estimated $5 million/yr in steam and electricity costs. The cogeneration energy savings is equivalent to the energy used by ~ 5,000 households in a year. The NIH COGEN reduces carbon dioxide (CO2; a greenhouse gas) emissions by ~ 58,000 ton/yr. It is the cleanest cogeneration plant ever built in the world, generating 44% less emission than the state-of-the-art cogeneration plant built in 2012. That is equivalent to the emissions from 10,000 cars.
NIH’s 22 MW COGEN plant produces relatively low cost steam and electricity at very high efficiency. The COGEN plant is one largest Cogeneration plant in U.S. Government and of the cleanest plants in the world with NOx emissions 44% lower that similar plants operating without add on emission controls. The COGEN meets 30% of NIH’s electricity requirement and provides 45% of NIH’s steam production.
Cogeneration saves NIH an estimated $5 million/yr in steam and electricity costs. The NIH COGEN reduces carbon dioxide (CO2; a greenhouse gas) emissions by 60,000 ton/yr compared to separate steam production and purchased electricity.
The CO2/greenhouse gas emissions savings are equivalent to removing emissions from 10,000 cars or 3,000 homes.
The COGEN produces enough electrical power, 190,000 MWh per year, to supply 14,000 average Maryland homes.
The total COGEN power output (280,000 MWh/yr as steam and 190,000 MWh/yr as electricity) of the COGEN is enough energy to keep a Boeing 747 at cruising speed for an entire year.