Upgrading to save energy
Over the last few years, Baltimore has been lowering its average $40 million energy bills for city facilities by retrofitting water and light fixtures and monitoring electricity use closely. It is combining those steps with alternative energy generation projects to replace electricity use with renewable energy sources.
Six years ago, Baltimore elected officials challenged all city agencies, bureaus and departments to reduce their energy consumption. Then, they created an Energy Office and charged it with reducing energy use throughout city agencies and closely monitoring utility service costs.
Since then, the city has increased energy conservation education among employees and scrutinized electric and water bills to identify high-energy use facilities. In September 2004, the city signed a performance contract with Milwaukee-based Johnson Controls to retrofit lighting, heating and air conditioning (HVAC) systems, and water fixtures in four of its largest buildings. The $4.2 million upgrades are guaranteed to save $525,000 per year for 14 years, and the savings will be used to pay for the new equipment, so the city did not have to pay any money up front.
Work began immediately on the Abel Wolman Municipal Building, the Charles L. Benton Building, Courthouse East and the Clarence M. Mitchell Jr. Courthouse. In all of the buildings, light fixtures were replaced with units that use less energy, incandescent lamps were replaced with compact fluorescent lamps and fluorescent exit signs were replaced with LED exit signs. Aerators were installed on all faucets to reduce flow from two gallons per minute to one-half-gallon per minute. Low-water-use urinals and low-flow shower heads were installed. All water leaks in restrooms, water closets and showers were repaired. Windows and doors were weather-stripped, and HVAC components were cleaned and serviced. Finally, a Web-based facility management system with an operator workstation was installed to centrally monitor building components.
The changes, completed by October 2005, improved the comfort and environmental conditions of the buildings and repaired operational and deferred maintenance issues. Since January 2005, the contractor has been tracking the city’s energy consumption through utility bills, finding that the four buildings have reduced use by 3.5 million kilowatt hours of electricity, 3,000 pounds of steam and 20,000 gallons of water.
To further reduce energy costs, Baltimore is exploring the use of wind and solar power to replace electricity. In September, the utility broke ground on a $14 million cogeneration facility that will convert methane gas from the Back River Wastewater Treatment Plant’s digesters to electricity. Like many city wastewater plants, the Back River process for wastewater treatment results in solids that are digested and produce methane gas. A substantial portion of the methane currently is burned off through onsite flares. “The new process will clean all of the gas burned on site, use some in existing boilers and heaters and use the rest to run generators, which produce the electricity,” says Hatim Jabaji, energy conservation office chief.
Johnson Controls joined with Long Beach, Calif.-based EarthTech to design and build the system that will generate 19.4 million kilowatt hours when complete in December 2007. Combined with other energy efficiency improvements at the plant, the project will save $1.8 million annually by providing renewable electricity to the city and capturing a waste stream for useful application.
