Stanford University
OP-8: Building Energy Consumption

Stanford regulates building temperatures with an Energy Management & Control System (EMCS). The EMCS allows Stanford to adjust temperatures based on occupancy via building scheduling through the system. Operational hours for each building are actively managed, and each week Stanford adjusts the HVAC operating schedule in up to 60 buildings to best align with specific hours of use.

LED task lights have been successfully piloted and deployed in new campus buildings and in some retrofit projects. One example is the LED task lighting in Y2E2 provided to each occupant. The building primarily utilizes natural light, but desks are outfitted with a 6-watt LED fixture that provides task lighting. The same LED task lights were also installed in Sweet Hall during a recent major renovation.

Occupancy sensors for lighting have been installed as retrofit projects in most classroom buildings as well as the public spaces and bathrooms of most student housing on campus. Occupancy sensors and timers for lighting have been installed in buildings across campus as part of the Building Level Sustainability Program (http://sem.stanford.edu/buildings_initiatives). Stanford's Guidelines for Sustainable Buildings also makes explicit mention of occupancy sensors as a preferred design strategy to increase efficiency (http://sem.stanford.edu/sites/sem.stanford.edu/files/documents/Stanford_sustainable_guidelines.pdf), and thus these sensors are now standard practice for new construction projects.

An excellent example of sensors can be found in the Y2E2 building, which includes both sensors for occupancy and photocell technology for daylight control.

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As part of the Stanford Energy System Innovations (SESI) program (http://sustainable.stanford.edu/sesi), Ground Source Heat Exchange (GSHE) could augment the basic heat recovery scheme of SESI by providing a more sustainable way to meet the 20% excess winter heating and 30% excess summer cooling needs of the university that can’t be met by building heat recovery. Phase I studies indicate that GSHE at Stanford is feasible. The university is now in Phase II studies that include exploratory borings to fully map subsurface hydrogeology, regulatory reviews, and other tasks necessary to determine the final feasibility of a GSHE addition to SESI.

For more information, please visit:
http://sustainable.stanford.edu/sites/sustainable.stanford.edu/files/documents/Stanford_SESI_General_Information_Brochure.pdf

Between 1987 and 2015, Stanford obtained the vast majority of its electricity from an onsite cogeneration facility that used natural gas as its fuel source. Combined heat and power (CHP) facilities like Stanford's generally see efficiencies that can exceed 70%, making them a desirable method for converting carbon based fuels into usable energy. Despite these efficiencies, cogeneration requires a reliance on fossil fuels that comprised a significant majority of Stanford’s greenhouse gas emissions. As a result, in the past five years, Stanford has transformed its energy supply to grid-sourced electricity (comprising of 65% renewables) and a heat recovery system. The new energy system is called Stanford Energy System Innovations (SESI). SESI’s new Central Energy Facility (CEF) came online in April 2015 and by the end of 2016, 65% of Stanford’s electricity supply will come from renewable sources.

The vast majority of campus building heating needs are now met by hot water generated at the CEF, which uses heat recovery chillers to recover the waste heat from the chilled water that Stanford uses to cool its buildings to create the hot water used for heating. Through this process, Stanford is able to meet 93% of its simultaneous campus heating needs with 57% of the waste heat from its chilled water. Due to the significant heat recovery and lower line losses of hot water compared to steam, the new energy system is approximately 70% more efficient that the previous combined heat and power process provided by cogeneration. For more information, please visit http://sustainable.stanford.edu/sesi.

Stanford is systematically reviewing the HVAC systems of 90 of its largest buildings, then adjusting or repairing the systems to ensure they work as designed. Technicians who conduct the reviews also recommend ways to further improve energy performance through ERP projects. The recommissioning of all 90 buildings was completed by the end of 2010 and all buildings are on a three-year renewal cycle.

Please see subsequent sections for details on major and minor retrofit programs.

Since the 1980s, Stanford has employed energy metering on all of its facilities to understand how and where energy is being used. Additionally, Stanford’s Energy Management & Control System is a computer-based centralized system for scheduling Stanford’s Central Energy Facility Steam and Chilled Water Plants, monitoring Stanford’s Cogen plant, and providing HVAC control for many campus buildings. Stanford utilizes a SCADA (Supervisory Control & Data Acquisition) system that provides real-time information and diagnostics of the campus power network (http://scadaweb/hv/).

ERP Express—Laboratory Equipment

Sustainability and Energy Management (SEM) and the School of Medicine (SOM) have partnered to offer financial incentives to labs that put DNA and RNA samples into room temperature storage and dispose of old ultra-low temperature freezers. The FY11 Cash for Clunkers program makes it easier for researchers to try room temperature storage technology and earn rebates up to $13,000. Researchers outside SOM can also earn cash back through ERP Express for Laboratory Equipment. A full history of the Room Temperature Biological Sample Storage program, including pilot project results, can be found online.

http://lbre.stanford.edu/sem/energy_retrofit_program

ERP Express—Office Equipment

Reduced electrical consumption within individual workstations and shared office areas is a major goal of the Building Level Sustainability Program. To support facility managers and building-level "green champions" seeking an extra incentive to make strategic purchases and operational decisions, ERP Express for Office Equipment offers small rebates for the purchase and installation of appliance timers and Smart Strips. Eligibility requirements, terms and conditions, as well as other important information about the rebate program can be found online.

Trees are consciously placed to provide shading and cooling for buildings and pavement with an emphasis on deciduous trees along the southern and western building exposures.

http://sustainable.stanford.edu/landscape_and_grounds

Stanford has utilized vending machine sensors for a number of years as a result of a student initiative. As an example, all vending machines within the Mitchell Building, home to the School of Earth Sciences, are equipped with motion sensors.

An effort is currently underway to catalog the vending machines without sensors on campus. Depending on the results of this study, Stanford will likely make a comprehensive effort to install these energy-saving devices on all vending machines that do not have them and provide rebates to departments for doing so.

WHOLE BUILDING RETROFITS PROGRAM

The university has allocated $30 million for major capital improvements to the most energy-intensive buildings on campus. The first overhaul, of the Stauffer Chemistry Building, was finished in June 2007 and resulted in a 35 percent drop in electricity use, a 43 percent cut in steam use and 62 percent fall in chilled water use. It also reduced carbon dioxide emissions associated with the building by 762 metric tons per year and cut energy costs by 46 percent in the first 12 months.

Retrofits on the dozen most energy-intensive buildings are scheduled for completion by 2014. Altogether, the improvements are expected to save $4.2 million annually and reduce total energy use in these buildings by 28 percent.

ENERGY RETROFIT PROGRAM (ERP)

The Energy Retrofit Program (ERP) has invested more than $10 million over 15 years in improving energy efficiency through building-level technology upgrades, such as T8 lamps and electronic ballasts, variable-speed drives for motors, LED exit signs and spectrally selective window film. The result of these custom projects is an estimated cumulative savings of over 240 million kilowatt-hours of electricity—about 15 months of the university’s current use—and prevention of 72,000 metric tons of carbon dioxide equivalent emissions. A program overview, project history, guidelines, and application details for custom rebates can be found on the ERP website.

http://lbre.stanford.edu/sem/energy_retrofit_program

Stanford’s new Central Energy Facility (CEF), which came online in April 2015, employs heat-recovery technology to significantly reduce the energy needed to heat buildings. The new CEF is 70% more efficient than the original cogeneration plant. Details in the descriptive fields of this credit capture the efficiencies gained from the CEF, but the data used in this credit represents performance years from before SESI came online, and thus the scoring of this credit does not capture the benefits that have and will continue to come from this new energy system.

Per STARS instructions regarding "source-site ratios" different from the default values provided, Stanford's justification for the use of 1.67 for each value reflects the actual documented plant efficiency of the Central Energy Facility during the performance year (FY13).