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Potential effects of plug loads on HVAC systems. Image: kW Engineering  


After years of neglect, lab plug load energy efficiency is receiving well-deserved attention. The results of a recent study on lab plug loads revealed a significant opportunity for energy savings. This work was done as part of a larger project to establish a center for independent, objective third-party energy testing and benchmarking of lab equipment: the Center for Energy-Efficient Laboratories (CEEL). As a California investor-owned utility funded project, the findings were focused on California and were contextualized within the broader context of the U.S.

Over 1,500 scientists responded to questions about 32 pieces of equipment across seven product categories. Data about the average number of equipment piece per lab and the operating hours for the equipment were used to calculate a total estimated energy consumption of plug loads in labs.

Key statistics from the three-month study include:

  • Lab square footage was calculated for 171 academic institutions, 1,351 life science research (LSR) organizations and 532 hospitals in California.
  • 1,199 scientists throughout the U.S. were surveyed online, including 269 from California. An additional 371 U.S. scientists were surveyed in person.
  • 78 facility and energy managers were surveyed online, of which 19 were from California.
  • An additional 14 facility managers in California were interviewed in person.

Over 116 million square feet of lab space was identified in just the market segments studied. Moreover, the market is growing. Federal funding for academic research increased by 2.5% in 2014. California’s LSR industry has been growing steadily at 5%/year over the past five years, and this rate is expected to rise. Private funding for hospital research continues to increase, and new construction of healthcare facilities grew by nearly 5% in 2014. The survey results corroborated these trends: 25% of respondents indicated their lab space would increase in the next three years.


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Energy consumption of lab equipment. Image: My Green Lab


Plug loads were estimated based on survey responses detailing the use of the most prevalent lab equipment identified in the study. The total electrical consumption by lab equipment in California is estimated to be at least 800 GWh/year, and may be as high as 3.2 TWh/year, as illustrated in the figure below.

Lab end-users and equipment manufacturers have overwhelmingly acknowledged the need for third-party testing, financial incentives and technical support to motivate a paradigm shift to greater energy efficiency in labs. Over 70% of scientists and facility managers surveyed view energy efficiency as “important” or “very important,” but many cited a lack of objective information and economic drivers as obstacles to change. Both of these issues must be addressed in order to take advantage of the significant opportunities for savings.

In addition, savings claims for plug load reduction projects are incomplete without an analysis of the associated HVAC systems’ response to the changes. Because of the high ventilation rates used in labs, the impact of load changes on HVAC energy usage often differs from that observed in other building types. Plug load reductions can be significantly amplified by HVAC system savings or, in the worst case, can be entirely nullified by a corresponding increase in electric resistance reheat. For the range of typical HVAC systems and space conditions in labs, the overall savings associated with a given plug load project can differ between locations by a factor of two. With an initial focus on high-efficiency ultra-low temperature freezers (ULTs) in California, the CEEL is working to quantify the state-wide magnitude of the potential overall energy savings by exploring the demographics of the HVAC environments of ULTs. To maximize the savings impact and return on investment, plug load efficiency efforts should generally first target those spaces where cooling loads are dominant.

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Allison Paradise is the Executive Director of My Green Lab, a non-profit dedicated to reducing the environmental impact of laboratories. She holds degrees in Neuroscience from Brown and Harvard, and prior to co-founding My Green Lab she worked as a scientific consultant.

Alison Farmer is a physicist with a deep dedication to energy efficiency in buildings. Dr. Farmer has extensive experience as an energy efficiency consultant for lab facilities, from strategic planning to detailed energy savings calculations. She has taught classes on energy analysis and is chair of the I2SL Lab Benchmarking Working Group. Dr. Farmer holds bachelors and masters degrees in physics from the University of Cambridge and a PhD in astrophysics from Caltech.