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Alexandria’s Discovery Middle School has trimmed its energy use by nearly 50 percent, thanks to a host of energy improvements.

Case Study: Alexandria Public Schools

Comprehensive energy program at Discovery Middle School achieves big energy savings, healthier indoor air 

In 2009, Alexandria Public Schools began an exciting and comprehensive “Go Green Initiative” that involved student learning and community impact, sustainable best practices, and cost savings. Part of the Go Green Initiative was an objective to get greener through aggressive energy management throughout the school district.

Aims and objectives. One goal of the energy management plan is to put each school in the district in position to achieve an ENERGY STAR® rating for energy efficiency. So far four of the ten schools in the district have achieved ENERGY STAR ratings above 75. (To qualify for the ENERGY STAR rating, a building must earn a score of 75 or higher on EPA's 1-100 energy performance scale, indicating that the facility performs better than at least 75 percent of similar buildings nationwide.) Another goal was to track, measure, and report performance. All 10 schools have remained up to date in tracking their energy performance in the Minnesota B3 Benchmarking database.

Implementation. For a portion of Discovery Middle School’s energy work, Alexandria Public Schools received an Energy Efficiency and Conservation Block Grant (EECBG) from the Minnesota Department of Commerce. Most of the grant was used for lighting system improvements. The existing lighting control system had been installed during the original construction of the building in 1994, so it was outdated. The school replaced inefficient high-intensity discharge and fluorescent fixtures with modern T8 fixtures to improve efficiency and lighting quality. The funding also supported the installation of 623 new occupancy sensors to control the school’s lighting, as well as the replacement of leaky main entrance doors. 

The lighting improvements were just a small portion of the energy project at Discovery Middle School. The Middle School and other Alexandria School District buildings made significant improvements to indoor air quality. Most notable of these measures was upgrading the heating, ventilation and air-conditioning (HVAC) controls system, said Trevor Peterson, director of Business Services for Alexandria Public Schools.

“The existing controls system was obsolete and not allowing the required amount of fresh air into the rooms,” Peterson said. “Modernizing the HVAC control system resolved the indoor air problem and also had the side benefit of allowing the school district to schedule HVAC equipment run times based on building occupancy instead of having the equipment run 24/7. A third measure was the installation of a high efficiency boiler for the spring and summer ‘shoulder’ heating seasons, so that the larger boilers didn’t have to run during these times.”

Outcomes--energy saved, operations improved. Through the B3 Benchmarking database, Peterson said the school district is able to monitor how the energy-saving improvements have reduced real costs. For Discovery Middle School, as shown in the B3 charts below, natural gas consumption decreased 45 percent from 2010 to 2012 and electric use decreased 39 percent from 2010 to 2012. Compared to 2010 performance, the school saved about $220,000 in 2011 and 2012. The B3 Benchmarking ratio for the Discovery Middle School is currently 62 percent, meaning it uses about 40 percent less energy than if it were a new building built to current energy codes.

Discovery Middle School annual natural gas consumption


Figure 1. The Minnesota B3 Benchmarking chart shows natural gas savings of 27 percent in 2011 and 45 percent in 2012.

Discovery Middle School annual electric consumption


  Figure 2. Energy tracking shows that electric use decreased 39 percent by 2012.

Documenting results. The B3 Benchmarking tool utilized by Alexandria Public Schools is available to all state, local government, and public school buildings. To add your building to this database, go to the B3 website and click on “Contact Us.”

Funding. The Discovery Middle School lighting system and entrance door upgrades were funded by a $58,200 EECBG grant provided via the American Recovery and Reinvestment Act of 2009. The lighting and entrance door upgrades cost $116,000; those improvements are projected to pay for themselves via energy savings in about 7 years.

Financing for the overall energy-saving project was aided by an energy conservation hot water boiler system rebate from the school district’s natural gas supplier. Also, through its electric utility, the school district benefited from a Missouri River Energy Services program called Bright Energy Solutions that offers rebates for lighting and other efficiency projects.

Resources for local government projects: Public institutions seeking energy efficiency improvements are encouraged to consult with the Minnesota Department of Commerce, Division of Energy Resources (DER) and their local gas or electric utility. DER provides technical support to local government units, state agencies, school districts, and institutions of higher learning that are seeking energy efficiency and renewable energy measures. Contact DER to discuss which of its energy efficiency programs can be of help.

All utilities in the state are mandated to achieve an annual energy savings of 1.5 percent of annual retail energy sales. Utility representatives can help assess opportunities for efficiency and identify what rebates may help finance projects.

The U.S. Department of Energy’s Advanced Energy Retrofit Guide for K-12 Schools also provides helpful resources for building retrofits (you’ll need to register with DOE to download your free copy). For more information on energy efficiency, including information on Minnesota’s B3 Benchmarking tool, contact the DER Energy Information Center.