| Overall Rating | Gold |
|---|---|
| Overall Score | 72.36 |
| Liaison | Andrew D'Amico |
| Submission Date | Nov. 13, 2024 |
Princeton University
OP-5: Building Energy Efficiency
| Status | Score | Responsible Party |
|---|---|---|
|
4.01 / 6.00 |
Saurahbi
Mishra Business Intelligence Manager Operations |
Part 1. Site energy use per unit of floor area
Performance year energy consumption
| kWh | MMBtu | |
| Imported electricity | 98,547,000 Kilowatt-hours | 336,242.36 MMBtu |
| Electricity from on-site, non-combustion facilities/devices (e.g., renewable energy systems) | 19,213 Kilowatt-hours | 65.55 MMBtu |
Stationary fuels and thermal energy, performance year (report MMBtu):
| MMBtu | |
| Stationary fuels used on-site to generate electricity and/or thermal energy | 1,469,201 MMBtu |
| Imported steam, hot water, and/or chilled water | 0 MMBtu |
Total site energy consumption, performance year:
Performance year building space
Floor area of energy intensive space, performance year:
| Floor area | |
| Laboratory space | 2,177,639.08 Square feet |
| Healthcare space | 35,210.73 Square feet |
| Other energy intensive space | 1,810,340.12 Square feet |
EUI-adjusted floor area, performance year:
Performance year heating and cooling degree days
| Degree days | |
| Heating degree days | 4,530 Degree-Days (°F) |
| Cooling degree days | 1,290 Degree-Days (°F) |
Total degree days, performance year:
Performance period
| Start date | End date | |
| Performance period | July 1, 2023 | June 30, 2024 |
Metric used in scoring for Part 1
Part 2. Reduction in source energy use per unit of floor area
Baseline year energy consumption
STARS 2.2 requires electricity data in kilowatt-hours (kWh). If a baseline has already been established in a previous version of STARS and the institution wishes to continue using it, the electricity data must be re-entered in kWh. To convert existing electricity figures from MMBtu to kWh, simply multiply by 293.07107 MMBtu/kWh.
| kWh | MMBtu | |
| Imported electricity | 78,748,196 Kilowatt-hours | 268,688.84 MMBtu |
| Electricity from on-site, non-combustion facilities/devices (e.g., renewable energy systems) | 0 Kilowatt-hours | 0 MMBtu |
Stationary fuels and thermal energy, baseline year (report MMBtu):
| MMBtu | |
| Stationary fuels used on-site to generate electricity and/or thermal energy | 1,469,670 MMBtu |
| Imported steam, hot water, and/or chilled water | 0 MMBtu |
Total site energy consumption, baseline year:
Baseline year building space
Baseline period
| Start date | End date | |
| Baseline period | July 1, 2005 | June 30, 2006 |
A brief description of when and why the energy consumption baseline was adopted:
The baseline was adopted because this timeframe was prior to the inception of the University’s Sustainability Plan in 2007-2008.
Source energy
Total energy consumption per unit of floor area:
| Site energy | Source energy | |
| Performance year | 0.15 MMBtu per square foot | 0.21 MMBtu per square foot |
| Baseline year | 0.21 MMBtu per square foot | 0.28 MMBtu per square foot |
Metric used in scoring for Part 2
Optional Fields
A brief description of the institution's initiatives to shift individual attitudes and practices in regard to energy efficiency:
Students are reminded by email to unplug or shut off their appliances and lights before they leave campus for extended breaks. Select buildings on campus, such as the Andlinger Center for Energy and the Environment, contain informational signage or digital kiosks that explain the energy-efficiency measures in the building. Additionally, the University offers an API for building and campus-level energy data. A month-long energy reduction competition among residential colleges in the spring is a specific outreach effort to raise awareness about energy-efficient practices while encouraging energy-saving behaviors—an extensive Campus As Lab program draws together students, faculty, and staff in collaborative work. There are many sustainability-focused programs led by different groups in the campus community.
A brief description of energy use standards and controls employed by the institution:
The University uses fully distributed digital control (DDC) systems in about 150 buildings on campus, which includes all of the heaviest energy-use buildings. Daily HVAC operation is scheduled to ensure systems are set back or off when spaces are unoccupied. The University uses several occupancy sensor technologies, including dual technology, vacancy sensors, wireless sensors, and light level (i.e., daylight harvesting) sensors. Digital thermostats, sensors, and radiant panel heating systems adjust heating and cooling temperatures according to various factors, such as occupancy and conservation targets of heating to 68°F in the winter and cooling to 78 °F in the summer. Buildings such as Frick Chemistry have been designed to facilitate cascading air flows, which allow laboratories and office areas to be cooled while minimizing the use of air conditioning. Heat recovery is used in many "once-through" buildings.
A brief description of Light Emitting Diode (LED) lighting and other energy-efficient lighting strategies employed by the institution:
Over 200,000 light fixtures have been upgraded from incandescent and fluorescent to LED technologies. This represents about 97% of the lighting on campus.
A brief description of passive solar heating, geothermal systems, and related strategies employed by the institution:
Princeton's first ground source heat pump system (geo-exchange) was installed in 2003. At the time, it was the largest in New Jersey, serving 200 units at Lawrence Apartments. Three other locations, Campus Club, Lakeside Graduate Townhouse complex, and the Lewis Center for the Arts complex are also heated and cooled with geo-exchange. In 2022, Princeton began the installation of one of the largest district energy-connected systems in the country. At ultimate build-out, it will have over 2000 geo-exchange wells and serve over 180 buildings. No passive solar is used on Princeton's campus.
A brief description of co-generation employed by the institution:
The electric generator, powered by a General Electric LM-1600 gas turbine that burns natural gas or diesel fuel, is the heart of a cogeneration system. The heat that would usually be wasted exhaust from the gas turbine is recovered to heat water and make steam. Through cogeneration, Princeton’s heating and power efficiency rises to 80 percent vs. 25-40 percent for a typical utility energy plant. The cogeneration plant can generate 15 megawatts of electricity, slightly less than Princeton’s average electricity needs on a given day. Princeton's gas turbine was the first in the world to earn certification to operate on bio-diesel fuel.
A brief description of the institution's initiatives to replace energy-consuming appliances, equipment, and systems with high efficiency alternatives:
Princeton is transitioning from combustion-based heating and power with an overall efficiency of 80% or less to heat pumps, thermal storage, and geo-exchange. Princeton is converting all central campus buildings from steam heat to district hot water. The existing district steam system is estimated to be 70% efficient. The new district hot water system is estimated to be 95% efficient. As buildings are being converted, other energy upgrades such as air sealing, insulation, and window upgrades are included where justified. Overall, the new systems should have a Coefficient of Performance close to 5.0.
Website URL where information about the institution’s energy conservation and efficiency program is available:
Additional documentation to support the submission:
Data source(s) and notes about the submission:
The information presented here is self-reported. While AASHE staff review portions of all STARS reports and institutions are welcome to seek additional forms of review, the data in STARS reports are not verified by AASHE. If you believe any of this information is erroneous or inconsistent with credit criteria, please review the process for inquiring about the information reported by an institution or simply email your inquiry to stars@aashe.org.