By Douglas J. Smith, IEng
MASSACHUSETTS COLLEGE of Liberal Arts (MCLA) has implemented a comprehensive energy services performance contract with Alliant Energy Integrated Services. Alliant Energy has helped the college implement energy conservation measures designed to significantly reduce energy consumption and save between $2.5 million and $3 million in energy costs over the next 10 years.
Under the program, MCLA implemented several energy conservation measures at its North Adams campus. These included installation of a new 700-hp central boiler, installation of a 75 kW cogeneration plant, and lighting and water conservation retrofits. The campus energy control system was also upgraded.
The $1.6 million performance contract was implemented under the Massachusetts Division of Capital Asset Management’s (DCAM) Energy Services Performance Contracting Program. Financing for the improvements was provided through a state Tax-Exempt Lease Purchase contract.
Installing new central plant boiler at MCLA. Photo courtesy of Alliant Energy Integrated Services.
MCLA will repay the costs through the energy savings that the improvements will generate. To generate additional energy savings the college has invested an additional $140,000 toward the installation of energy efficient windows.
Alliant Energy Integrated Services, through its Energy Assets predecessor company, was awarded the contract in November 1999. The first priority was the preparation of a detailed technical audit with the primary goal to determine as many high priority capital improvements as possible that could be paid for from energy cost savings. Construction began in November 2000 and was completed in December 2001.
A Variety of Energy Savings
The college’s two existing central plant boilers were 32 years old and operated at an efficiency of 70-75 percent. These boilers supplied the space heating and hot water for the campus.
One of the boilers has been replaced with a 700-hp dual-fuel Cleaver Brooks fire-tube boiler. The second boiler was left in place and is used as a backup. The new boiler, with an efficiency of 83-87 percent, is fitted with low NOx burners and is capable of firing No. 2 oil or natural gas. An inefficient stand-alone boiler in a satellite building on the campus was also replaced with a new gas-fired boiler.
In the steam supply system, the old steam traps were a constant problem that often caused damage to the equipment from water hammer. This has now been rectified with the installation of new orifice-type traps. Not only do the new traps save energy and reduce maintenance costs, they also have a ten-year warranty.
At the Campus Center, Alliant installed a new gas-fired 75 kW Tecogen reciprocating cogeneration unit. This unit supplies electricity and heat for a nearby swimming pool, domestic hot water and space heating systems. Thermal energy from the reciprocating engine’s jacket water is used for the heating and hot water.
Previously the Campus Center’s electricity was supplied by the local electric utility and the space heating by the central boilers. According to Alliant Energy, the savings on the cost of electricity and heating from installing the cogeneration plant is a buffer for future energy price fluctuations.
MCLA also upgraded the campus’s inefficient lighting. The lighting upgrade included installing new fluorescent lamps, fixtures, and ballasts. Not only are these more efficient, they also provide more and better distribution of light.
Additional energy savings were achieved by installing occupancy sensors and by installing controllers on the vending machines. These sensors can turn the lighting and refrigeration systems off when the machines, or the rooms, are not in use. To improve energy efficiency further, all of the windows in the campus building were replaced with energy efficient insulated models.
Besides the economic and capital improvement benefits associated with this project there are societal benefits. These include annual reduction in the use of natural resources and pollution abatement from using less electricity and natural gas and the reduction of CO2, SO2 and NOx emissions. With the energy conservation measures, MCLA now uses 1.5 MWhr/year less electricity and 174,000 Ccf less natural gas/year.
Emissions of CO2, SO2 and NOx have been reduced by more than 4.5 million pounds annually. This is equivalent of removing 465 automobiles each year or the yearly planting of 965 trees.
“The projects implemented by MCLA provide multiple benefits,” said Chuck Castine, president of Alliant Energy Integrated Services. “These measures not only reduce operating costs, but they also improve the college’s infrastructure, benefit the environment through reduced emissions and reduce their dependence on imported energy resources,” he said. According to Reynolds Thompson, MCLA facilities director, MCLA has had a long-standing commitment to the environment and energy conservation.