Central Power Plant
Constructed in the neo-Gothic style, the Central Power Plant has been meeting campus energy needs since 1918. The plant originally used coal to meet the University’s growing energy needs; however, today the plant is a co-generation facility that is primarily fueled by natural gas. The plant provides electricity, steam heating, and chilled water to buildings on Yale’s main campus.

Consisting of three 6.1 megawatt gas turbines and three 1.5 megawatt peaking and emergency diesel generators, the Central Power Plant has a total capacity to produce 18 megawatts of electricity and 340,000 pounds per hour of steam for heating. The facility also has five steam driven chillers that can provide the campus with 14,600 tons of chilled water when at full capacity.

Steam and chilled water for heating and cooling are distributed through a series of linked pipes that make up 14 linear miles of steam tunnels, which pass under and interconnect nearly every central campus structure. Most of the steam and chilled water eventually returns to the plant, where they are cleaned of impurities.

Converting the Central Power Plant to a co-generation facility has significantly increased the efficiency of the University’s energy production and reduced the amount of energy that Yale buys from the local utility provider, United Illuminating. In addition to increased energy efficiency, utilizing co-generation considerably reduces greenhouse gas emissions and will help Yale achieve its GHG reduction commitment

What is Co-Generation?
Co-generation, also known as combined heat and power, is the production of electricity and heat from a single fuel source. Considered highly efficient, co-generation captures heat lost during the production of electricity and converts it into useful thermal energy, usually in the form of steam or hot water. Co-generation systems are typically 60-80 percent efficient which is significantly more efficient than the traditional power plant efficiency of approximately 30 percent.

These efficiency gains also result in cost savings, reduced air pollution and greenhouse gas emissions, increased power reliability and quality, reduced grid congestion and avoided distribution losses.

Gas Turbine with Heat Recovery Unit

Source: Combined Heat and Power Partnership, USEPA

Sterling Power Plant
Sterling Power Plant is a natural gas and oil-fueled heating plant that supplies the Yale Medical School and Yale New Haven Hospital with steam and chilled water. The plant is capable of producing 350,000 pounds of steam per hour and 19,900 tons of chilled water.

Currently, a project is underway to convert the power plant to a cogeneration system, similar to the system already in place at the Central Power Plant. The project consists of installing two 7.5 megawatt cogeneration units in a site that currently holds an unused underground water storage tank. The implementation of cogeneration will enable the plant to simultaneously produce electrical and thermal energy. The units will improve the efficiency of Sterling Power Plant, saving up to 20,000 metric tons of carbon equivalent per year. The project is slated for completion in 2010.

Class of 1954 Environmental Science Center Fuel Cell
Yale contributes to the production of clean energy on campus through the use of a 250 kW hydrogen fuel cell. The fuel cell was installed at the Class of 1954 Environmental Science Center, near the Peabody Museum, in 2003. At 250 kilowatts, the fuel cell produces 40-50% of the electricity for the Science Center. Its electricity production alone is 47% effective, and the addition of heat recovery allows for up to 60% efficiency -- enough for the EPA to recognize Yale with a combined heat and power leadership award.

To learn more about Yale’s fuel cell, click here.
Visit the Connecticut Hydrogen Fuel Cell Coalition here.

Biodiesel
Biodiesel is an alternative fuel that can be used in diesel engines with little to no modification. Biodiesel is made from renewable resources, including vegetable oil and fat. The fuel burns more cleanly than traditional diesel and is non-toxic. Biodiesel can be combined with traditional diesel to increase performance, especially at cold temperatures. Mixtures are denoted by the abbreviation ULSD/B#, which indicates the use of ultra-low sulfur diesel and biodiesel of a certain percentage, indicated by the number.

Yale is reducing transportation-related emissions by running the bus fleet on ULSD/B20 bio-diesel. ULSD/B20 bio-diesel reduces the sulfur content from a regular diesel level of 500 parts per million to 50 parts per million. The use of bio-diesel also reduces Yale’s transportation-related petroleum usage by 20%, or 20,000 gallons.

Solar & Geothermal Technologies
Fisher Hall at the Yale Divinity School provides a platform for 40kW solar system consisting of 255 solar panels. Installed in 2007, the solar panels generate approximately 45,200 kilowatt-hours of electricity annually, which covers approximately 17% of the hall’s energy demand.

The School of Forestry & Environmental Studies’ newest building, Kroon Hall, is seeking carbon neutrality by incorporating several renewable energy technologies into the design of the building —passive solar, a 100kW solar system , evacuated solar hot water tubes and a geothermal system for heating and cooling.
Plans are currently being developed to install solar panels at some of the undergraduate colleges as well. One project will use Uni-Solar’s thin film PV panels to cover the southern roof of the Swing Dormitory building. Rated at 20 kW, the panels are expected to provide 3–5% of the building’s electricity.

To see real-time statistics of the energy generated by the Fisher Hall solar panels, please visit this site:

Wind Power: Prospect Street Windmill Project

Another pilot project will use small wind turbines known as ‘micro-wind’. The ‘architectural wind’ turbines (1 kW each) at the Becton Center, built by AeroVironoment Inc., capture energy from the wind traveling up the side of a building.

At 6.5 feet tall and weighing 60 pounds, these compact units require a breeze of just 7 mph (3.1 metres/second) to start up. For more information, continue reading here...

Energy efficiency is a primary goal for Yale University. In order to meet Yale’s greenhouse gas reduction goal while the campus continues to expand, efficient practices are implemented in both existing and new buildings. Each energy saving strategy is evaluated to determine the carbon reduction per operating dollar incurred. The strategies with the highest returns are implemented first, to ensure the most efficient planning. Each individual step can add up to significant total amounts of energy saved.

To learn more about energy conservation at Yale, please visit: http://java.facilities.yale.edu/cmp/

Recent measures taken at Yale to reduce energy use include:

• HVAC Recommissioning of 90 Buildings (all DDC type)
• Building Temperature Standardization (DDC Buildings)
• Lighting Occupancy Sensors in 85+ Buildings
• High Efficiency Filters in all HVAC units
• Rescheduling of Lab "Occupied" hours
• Lab Rebalance & Air Change Red'n 15 to 9 (6 Buildings)
• Sensible Heat Recovery retrofits in Labs
• Window Replacements in various Buildings.
• Programmable Thermostats in Smaller Buildings
• Demand Ventilation (C02 sensors & VFDs)
• Continuous Commissioning at Key Lab Buildings
  

For more detailed information on Yale’s conservation measures, please visit:
http://www.yale.edu/sustainability/GHGReductionMeasures1.pdf

Project Lux
In an effort to decrease energy consumption and increase environmental awareness in the residential colleges, the Student Taskforce for Environmental Partnership (STEP) has implemented Project Lux, a competition in energy efficiency. Each college competes to accomplish the largest reduction in energy consumption, as compared to the previous three years. Through this program, the undergraduate colleges hope to achieve an overall decrease in energy use of 15%. To see which college is leading the charge to reduce its energy use go to http://java.facilities.yale.edu/cmp/

DEPARTMENTAL EFFICIENCY HIGHLIGHT
Information Technology at the Law School
The Law School Information Technology (IT) Services department, as well as many other IT departments around campus are taking active steps to reduce energy use within computer labs. Specifically, the Law School has purchased Energy Star-rated servers and initiated “server virtualization” to increase server efficiency. Desktop computers now have automated power saving features and are set to “sleep” mode when not used.

To learn more about sustainability initiatives at the Law School, please visit this page.