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The new T8 fluorescent light fixtures have decreased energy use and improved lighting quality for the Brooklyn Center Public Work Facility.

Case Study: Brooklyn Center Public Works Facility

Lighting retrofit saves energy, improves lighting quality

High electric costs and poor lighting quality persuaded Brooklyn Center to implement a major lighting retrofit at their 40,500 square-foot Public Works Facility. The city replaced the existing high pressure sodium and T12 fluorescent light fixtures in the vehicle storage and mechanic’s bay areas of the building with new T8 fluorescent light fixtures.  

According to John Harlow, Brooklyn Center deputy director of Public Works, “The lighting project had two significant outcomes: the decrease in energy use and a notable increase in light quality/visual acuity. The improved quality resulted in a noticeably safer work environment—dark locations of the building were eliminated and employee safety relevant to trips and falls was improved.”

Lighting changes provide big savings

The Minnesota B3 Benchmarking charts below show the electricity savings and CO2 emission reductions of the building from 2010, before improvements, to post-project years of 2011 and 2012. Electric consumption decreased 14 percent in 2011 and 15 percent in 2012, and CO2 emissions were reduced by the same percentages for the respective years. Brooklyn Center is saving about $4,000 a year with the lighting upgrades.

The B3 Benchmarking ratio for the Public Works Facility was 152 percent before the project, meaning it used about one half more energy than if it were a new building built to current energy codes. By 2012, after the lighting retrofit, the B3 score improved to 127 percent, meaning the building is using about a quarter more energy than a new building built to current energy codes. The score above 100 percent indicates there still may be additional energy conservation opportunities. 

Annual electric consumption

Figure 1. This Minnesota B3 Benchmarking chart shows 15 percent electric savings 2010.

Annual CO2 emissions

Figure 2. CO emissions were reduced 14 percent in 2011 and 15 percent in 2012.

B3 Benchmarking tool available 

The Minnesota B3 Benchmarking tool is available for all state, local government, and public school buildings. It allows users to track their buildings’ energy use, monitor the performance of energy improvements, and allow building portfolio managers to readily identify poor energy performance. The B3 tool is provided by the Minnesota Department of Administration and the Minnesota Department of Commerce and is funded by all utilities. To add your building to this database, go to the B3 website and click on “Contact Us.” 

EECBG, utility funding

About half of Brooklyn Center’s $16,700 project cost was covered by an Energy Efficiency and Conservation Block Grant (EECBG) from the Minnesota Department of Commerce (via funding from the American Recovery and Reinvestment Act of 2009). Brooklyn Center also received an Xcel Energy rebate of more than $8,000 to complete the financing. With the national phase out of magnetic ballasts and T12 lamps, many Minnesota utilities no longer offer rebates for converting such lighting systems. However, with rising demand and energy charges for commercial consumers, companies that still have these in place may find it cost-effective to replace them even without rebates. Most electric utilities provide rebates to support change outs of other older lighting systems and to help fund other lighting efficiency improvements.

Resources for public building projects

When seeking energy upgrades, cities are encouraged to consult with the Minnesota Department of Commerce, Division of Energy Resources (DER) and their local utilities. DER provides technical support to local government units, state agencies, school districts, and institutions of higher learning that are seeking to implement energy efficiency and renewable energy measures. Contact DER at to discuss which of its efficiency programs may be of help.

Utility representatives can help assess opportunities for efficiency and identify rebates to help finance projects. Utilities in Minnesota are mandated to achieve an annual energy savings of 1.5 percent of annual retail energy sales. Energy improvement projects such as Brooklyn Center’s help achieve that energy savings requirement.

The U.S. Department of Energy’s Building Technologies Office also provides helpful resources for building retrofits.