The Duke University main campus has one of the largest utility networks in the southeastern United States. The University manages heating, cooling, and electricity infrastructure for over 20 million square feet of buildings on Duke’s main campus in Durham, North Carolina. The University’s annual energy use is almost evenly split between electricity and natural gas and was over 2.3 million MMBTU in 2018. Depending on the utility system, Duke University uses the equivalent energy and water of 10,000-40,000 typical residential homes.
As of July 2021, Duke University purchases electricity from Duke Energy and natural gas from Dominion Energy North Carolina. Steam and hot water, which are produced by burning natural gas in two thermal energy plants on campus, are used for space heating, sterilization, humidification, dehumidification, and domestic hot water in university buildings, laboratories, clinics, and Duke University hospital. Electricity is used for lighting, plug-in devices, chilled water generation, and air-conditioning.
Campus Efforts to Reduce Energy Use
Since developing its 2009 Climate Action Plan, Duke has launched an effort to both reduce on-campus energy use and transition to cleaner energy.
Energy Efficiency Upgrades
A significant portion of Duke’s energy reduction has come from numerous energy efficiency projects, ranging from LED lighting upgrades, HVAC scheduling, efficiency improvements in building mechanical systems, and district steam to hot water conversion. In phase 1 of Duke’s energy efficiency upgrades, the University completed LED lighting upgrades for 15 buildings -- accounting for approximately 1.5 million square feet. The total lifetime cost savings sums up to nearly $700,000. In phase 2, Duke completed LEED building upgrades for 14 major campus buildings (including Wilson Gym and Bryan Center) -- equivalent to about 1.7 million gross square feet. The total lifetime cost saving from these upgrades is $339,000.
Sustainable Buildings and Construction
Starting in 2004, Duke established a goal for all new construction and major renovation projects to achieve LEED Silver certification. As of July 2021, Duke has 45 LEED-certified buildings (12 gold-certified, 3 platinum, and 25 silver). Along with these 45 certified buildings, Duke has an additional 6 buildings registered for certification, which in total cover almost 5.2 million gross square feet (GSF), equivalent to 32% of the University’s total GSF.
In 2018, Duke University realized a need to push beyond the current LEED building policy to further Duke’s building sustainability. To this end, Duke University developed the High Performance Building Framework, which was finalized in 2019. The framework takes a holistic view of green building at Duke by outlining an improved process for planning campus buildings, a rigorous sustainable design standard for all new buildings and major renovations, and a new tracking and rating system to examine how facilities perform even after construction to ensure that buildings reduce energy and potable water use.
In addition to energy efficiency upgrades on campus, Sustainable Duke and other campus partners (HR, student organizations, FMD, etc) have engaged students and employees to reduce their energy use. One of the main avenues for behavior change is Sustainable Duke’s green certification program, which is a sustainability checklist with recommendations to reduce energy and water use, increase use of alternative transportation options, reduce waste, and incorporate student and employee health and wellness practices. There are different checklists for workplaces, labs, dorms, events, and classrooms and thousands of members of the Duke community have participated in this long-running program. Staff from Sustainable Duke also host departmental workshops that can be tailored to the specific department’s interests. Lastly, Duke hosts campus-wide competitions occasionally, which encourages participants to adopt sustainable practices that can be employed on campus and at home.
To date, Duke has 1 MW of solar photovoltaics and hot water installed in the following locations:
- Bryan Center - 80 kW solar hot water
- Smart Home - 10 kW solar PV
- Grainger Hall - 45 kW solar PV and 15 kW solar hot water
- Research Drive Parking Garage - 750 kW solar PV (pictured above)
- Chilled Water Plan #3 - 100 kW solar PV
The university will bolster its renewable energy capabilities through the purchase of 101 megawatts of solar capacity from three new solar facilities planned for North Carolina. The university has partnered with Pine Gate Renewables to build the new solar farms, which are expected to be operational before 2024. It is the largest such initiative in North Carolina under Duke Energy’s Green Source Advantage program.
Renewable Natural Gas
The University’s initial involvement with biogas was centered around purchasing carbon offsets achieved by capturing and destroying methane released by the state’s many swine farms. Duke worked in partnership with Duke Energy and Google at Loyd Ray Farms to establish one of the only systems in the state to meet environmental standards endorsed by community and environmental groups which reduced methane emissions for Duke University and Google and generated renewable energy for Duke Energy. The methane-based biogas was captured in a covered bio-digester and was combusted in an on-site microturbine thus turning the biogas into renewable electricity. The process of destroying the methane also yields carbon offsets as methane is a much more potent greenhouse gas compared to carbon dioxide with a global warming potential of 28-36 times higher than carbon dioxide (Source: EPA).
In 2020, Duke formed a partnership with South Carolina-based GreenGasUSA. Working at an existing facility at a commercial vegetable cannery in South Carolina, GreenGas will install equipment to capture the escaping methane from vegetable waste lagoons, process the gas to meet heat content and chemical makeup standards of pipeline natural gas, and inject it into existing interstate pipelines for eventual use in the district energy system that heats East, West and Central campuses in Durham.
Duke will buy a portion of the project’s output and begin receiving 95,000 million BTUs of fuel per year, displacing approximately 6% of the natural gas used for district heating of the main Durham campus. The combined effect of the fuel displacement and the capture and destruction of methane from the McCall wastewater treatment site will be sufficient to completely neutralize the climate impact of the university’s remaining natural gas use.
Future of Energy at Duke University
With the past and future energy efficiency, plant efficiency, and renewable energy initiatives (on top of reduction from employee commuting and air travel), it is estimated that Duke University will near carbon neutrality with a total reduction of 75% compared to its 2007 baseline. The remaining emissions will be reduced through the use of high-quality carbon offsets.