A Graduate Course in Energy Conservation
- By Michael Fickes
- January 1st, 1999
If all goes well, the University of Michigan (UM) in Ann Arbor will reduce its energy usage by more than 71 million kilowatt-hours per year and slash $5 million from its annual utility bill by 2005. The savings will come from a campuswide tune-up and renovation of lighting and mechanical equipment in 119 general fund buildings spanning 13.5 million square feet.
At the University of Michigan, general fund buildings provide academic and research space and account for approximately 70 percent of the facilities on campus. The expected $5 million savings represents about 12.5 percent of the current $40 million spent on gas and electricity in these buildings.
In addition, the reductions in energy use will eliminate atmospheric emissions of more than 128 million pounds of carbon dioxide.
Energy Star - A Bright Idea
The university has undertaken this work in conjunction with a program developed by the EPA. Called the Energy Star Buildings Partnership, the program calls upon partners to upgrade to energy-efficient lighting and other energy-saving mechanical system technologies within seven years. The university has opted to complete its Energy Star work in six years, retrofitting about 20 of its 119 general fund buildings per year.
Energy Star partners sign a Memorandum of Understanding, which lays out the responsibilities for both the partner and the EPA. Under the terms of the memorandum, partners agree to upgrade lighting and mechanical systems, maintain or improve indoor air quality in upgraded buildings, follow Energy Star energy-efficiency and profitability criteria, report progress to the EPA yearly, inform communities affected by the work about what is being done and allow the EPA to use the results to promote its programs.
In turn, the EPA agrees to provide technical support in the form of written materials and guides, a technical hot-line and software tools to aid in estimating the energy savings and environmental benefits that would accrue from specific upgrades. The EPA also agrees to advise and assist partners in planning and implementing upgrades, provide marketing materials to help communicate programs to interested parties, publicly recognize partners for their participation, provide special recognition for buildings achieving the greatest energy-use reductions and allow partners to use the Energy Star logo on renovated buildings.
Since the University of Michigan signed up for the program on July 1, 1997, the Utilities and Maintenance Services Department has completed work on 17 buildings and will complete two more buildings sometime early this year.
In addition, the department has identified and begun work on approximately 20 more buildings targeted for completion by the end of the second year of the university’s Energy Star program.
An Energy Star Is Born
The Energy Star program recommends a five-stage process for energy conservation work. The university’s Energy Star plan includes work under each of these headings.
1. Lighting fixture retrofits. Here, lighting fixtures are retrofitted to accept efficient new electronic ballasts and low-wattage, high-efficiency lamps.
2. Tune-up. The second phase of work focuses on cleaning, adjusting, and calibrating electrical and mechanical equipment to make it operate more efficiently. Affected equipment includes building controls such as thermostats and occupancy sensors; steam traps; heat exchanger tubes in the condenser, evaporator and boiler; and the overall heating and cooling systems.
3. Load reductions. In this stage of the program, the walls, roofs and windows forming the building envelope are tightened to reduce the necessary loads on the electrical, heating and cooling systems.
4. Fan system upgrades. According to a recent EPA study, more than 60 percent of building fan systems are oversized by at least 10 percent. Stage four recommends right-sizing fan systems and following up with the installation of variable-speed drives, energy-efficient motors and belts, and improved controls for these systems.
5. Heating and cooling system upgrades. The final stage of the program costs the most, but presents an opportunity to capitalize on the load reductions achieved during the first four phases of Energy Star. According to EPA literature, the cumulative effect of these various load reductions allows one to install heating and cooling systems that are both energy efficient and properly sized to accommodate smaller loads.
"While these five steps are not magic, they are a logical way to go through a building and touch on all the different features related to energy conservation," says Donald Lystra, UM’s utilities engineer and Energy Star program director. "The first step, the lighting retrofit, is the easiest to do and the one that offers the most guaranteed benefits. The least expensive stage is the second phase tune-up. For the most part, this involves only labor expenses, and so the payback is pretty good.
"Each of the last three stages represents capital changes on a building, and you are spending relatively large amounts of money in return for future benefits.
"We could have done this on our own, but it’s nice to have it laid out in such detail," continues Lystra. "The EPA provides materials that people without technical backgrounds can understand and support. Per-haps for us, however, the benefit of working with the EPA involves positive publicity."
Rich Robbens, the university’s director of utilities and maintenance services, agrees. "The EPA supplies materials that help to promote this work to the campus community. Working with the EPA also gives a level of credibility to the program. When we’re done with a building, for example, the EPA certifies it, saying that this is the best that this building can be without investing a tremendous amount of money."
Cost, Savings and Payback Schedules
At the end of the university’s first Energy Star year, last July, the maintenance department had identified and completed work on nearly 53 lighting and mechanical projects. According to Lystra, labor and materials for this work cost approximately $2.2 million.
"We expect to save about $600,000 per year from this group of projects," Lystra says. "That will give us a 3.7-year payback. One of our criteria for approving projects is that the payback must come in five years or less."
Since none of the renovations have been in place for more than a year, Lystra can do no more than estimate eventual annual savings totals. Quarterly comparisons of costs have been made, however. "We compared the use of electricity in 13 buildings for July, August and September of 1997 and 1998 - before and after the improvements," he says. "We found a sizable reduction in electricity use in each building, from six percent to 23 percent. On average, those 13 buildings used 15 percent less electricity. We were surprised by the amount of the reduction.
"We haven’t evaluated natural gas savings as the renovated buildings haven’t been through a winter yet. We do plan to evaluate natural gas savings this winter."
Michael Fickes is a Baltimore-based freelance writer with experience in higher education issues.