solar panels

Let the sunshine in: Princeton's 27 acre solar installation with 16,500 photovoltaic panels.

Princeton is committed to measurable greenhouse gas reduction through local verifiable action. The University's goal is to reduce direct emissions to 1990 levels by 2020, even while increasing building square footage to accommodate world class research endeavors and an expanded campus population.


Reduce absolute campus greenhouse gas emissions to 1990 levels by 2020.


  • staff in control room

    Since the University’s Energy Master Plan was established in 2008, annual energy savings of approximately $7 million and annual CO2 reductions of more than 37,000 metric tons have been realized or identified for implementation.

  • jadwin LED lights

    In 2014, the university began replacing and recycling 200,000 lamps with LEDs which will save approximately 14 million kilowatt hours, 9,690 metric tons of net CO2 and realize an annual energy cost savings of $1.2million. The campus-wide LED installation is expected to be completed by January 2018.

  • steam traps

    Other energy conservation measures were identified and implemented including: steam trap replacements (pictured), pump upgrades, air compressor upgrades, variable speed drive installations, and the addition of a booster chiller in E-Quad which received a 2017 Innovation Award from the International District Energy Association (IDEA).

  • reunions solar tour

    For Earth Day 2017, the Campus as Lab Program and Energy Plant Facilities staff hosted tours of Princeton’s 4.5-megawatt solar field. The tours were attended by students, faculty and staff. Also for the first time, Reunions attendees (pictured) were given an opportunity to tour the solar field.

  • billion dollar green challenge logo

    As part of a $45 million investment in efficiency upgrades for the campus, Princeton has committed $5,000,000 to a revolving loan fund as a participant in the Billion Dollar Green Challenge.

  • STARS Silver Award

    The AASHE Sustainability Tracking, Assessment & Rating System (STARS) allows metric-driven progress assessment across operations and academics for North American higher education and has recognized Princeton at the Silver leadership level

  • dining hall plates and silverware

    As part of its waste and energy reduction efforts, Dining Services upgraded dishwashers and completed conversion to “tray-free” dining in all of its residential dining halls in 2011, reducing annual campus CO2 emissions by an estimated 23 metric tons. 

  • Lakeside Graduate Apartments under construction

    A geothermal heating and cooling system was installed at the new Lakeside graduate housing community. Notably, the University selected the technology after applying its internal "carbon tax," which is used when comparing major building systems that cost more upfront but result in economic and environmental benefits over time.

  • The University is on track to reduce CO2 emissions to 1990 levels (95,000 metric tons) by 2020. The University has accomplished this through investments in energy upgradesrenewable energy resources, and an award-winning co-generation energy plant

  • solar array

    Princeton's new 5.3-megawatt solar array went online in fall 2012. The system provided approximately 5.4 percent of campus electricity last year. Notably a third party will claim the CO2 reductions until the array is paid for, near 2020. At that time, Princeton will begin claiming reductions. View REAL TIME energy data provided by Wattvision.

Total Campus Emissions & Square Footage of Main Campus Building Area

energy infographic
energy infographic

What’s Next

  • Re-evaluate long term greenhouse gas reduction goals and assure alignment with leading research recommendations. 

  • Assess how to track the impact of Princeton energy initiatives on and off campus.

  • Re-evaluate Princeton's internal CO2 tax to maximize impact.