Although there is no recurrent funding stream for energy efficiency improvements, internal campus allocations for this purpose total almost $3 million since 2003. Lighting replacement projects, retro-commissioning of existing buildings, and improvements to HVAC equipment constitute the bulk of expenditures to date. Investing $1 million in 2006 saved the campus $263,799 annually. This 3.7 year payback is for energy savings only and does not include the reduced maintenance, longer equipment life, and improved work environment that will also result. This return on investment is higher than the stellar returns recently achieved on UNC's endowment.
Commissioning and Energy Modeling
UNC design guidelines require energy modeling and commissioning on all new buildings begun after July 2006. Commissioning is a quality assurance process that ensures buildings operate as intended. Retrocommissioning refers to commissioning undertaken on an existing building. Chapman and Caudill laboratories were the first buildings to be commissioned from design through operations. Carroll Hall, MBRB, and Bioinformatics were retrocommissioned during FY05-06. Campus engineers have estimated an annual savings of more than $155,000 and a 2.5 year payback period for these three retrocommissioning projects.
HVAC Shutdown Programs
The Energy Monitoring and Control System (EMCS) staff saves energy by cycling HVAC (heating, ventilation, and air conditioning) system fans off at night and on weekends. Night shutdown programs are in place in 24 buildings across campus and generate annual savings of approximately $106,000.
Lighting
Information Technology Services (ITS) remotely controls multimedia systems and lighting in classrooms across campus. In 2006 ITS implemented an energy conservation program that turns off classroom lights between midnight and 6 a.m. In classrooms that do not have occupancy sensors, lights dim to 50% after the multimedia system is shut down. If the next professor needs more light, they can turn the lights up using the wall switch or the touch panel.The ITS energy conservation program is estimated to eliminate 95,414 kilowatt hours of electricity use each year, saving more than $6,679.
The Energy Conservation Manager has set the goal of replacing all T-12 lighting on campus with T-8 or T-5 lamps by 2010. Eleven building upgrades were undertaken in 2006 for an estimated reduction of 761,090 kilowatt hours and a cost savings of $53,274 each year. The NC Green Building Technology Database has detailed information about lighting upgrades completed in Hanes Art Center, the General Storeroom and Carmichael Gymnasium.
Motors and Boiler Controls
Installed in the most recent rounds of energy efficiency upgrades, boiler controls allow natural gas to be used more efficiently. At UNC, boiler controls will create annual savings of $25,600 for a payback time of 1.6 years.
The University has also installed more efficient motors to power HVAC fans, elevators and other equipment, resulting in annual savings of 159,000 kilowatt hours, or $11,130.
Thermal Storage
In 2006 a new chilled water plant and a 5 million gallon thermal storage tank were completed on South Campus. The thermal storage system allows the University to produce chilled water at night when electric rates are lower. During routine summer operation, the new system reduces peak campus electrical loads by 12 megawatts, or 13 percent .