Authored by Abby Meuser-Herr, January 23, 2017
In August 2016, LHB’s Minneapolis Office interval meters went live! After over a year of budgeting, planning, installation, and calibration, our interval meters began logging disaggregated electricity use and feeding it to B3 Benchmarking via our wireless network. These small pulse meters are connected to each of our five electric panels and measure the amount of electricity used every 15-minute block of time. This equipment not only enables us to identify the distribution of electricity use, but also provides insight into our energy use patterns – both essential in the analysis and management of energy use.
Prior to the interval meter installation, the data center electric panel fed into the same utility meter as one of the equipment plug load panels (intended to measure workstation and common area equipment energy). This configuration limited our ability to effectively identify opportunities for performance improvements relative to national averages, energy targets, and our self over time. To solve this, an additional interval meter was installed as a sub-meter on the data center electric panel to disaggregate the data center electric use from the meter total. Now, actions taken to improve efficiency measures made on the data center or at the desktop can be individually measured and relative impact evaluated.
LHB Minneapolis Office August – December 2016 electric consumption
Data from the most recent U.S. Energy Information Administration (EIA) Commercial Building Energy Consumption Survey (CBECS) presents a nationwide average office Energy Use Intensity (EUI) of 77 in 2012, down 17% from 93 in 2003. The survey disaggregates the EUIs by end use, which generally can be divided into three categories – mechanical systems, lighting, and plug loads.
A comparison of LHB-MSP’s energy use relative to the national average is depicted below. Energy attributed to our space heating, cooling, ventilation, and hot water are not available because sub-metering that data from the total building system is currently cost prohibitive. However, in a comparison of our lighting and plug loads, which includes the data center, LHB outperforms the national average. Our LED lighting system is 66% more efficient than an average office building and saves LHB approximately $3,400 per year. Our almost comparable plug load energy use suggests that LHB has opportunities for improved efficiency which could be uncovered through a more detailed analysis of the daily and weekly interval data. LHB is currently participating in a Small Embedded Data Center Study led by CEE which is evaluating strategies to reduce data center energy demands. Findings from this study will be employed as we continue to monitor and manage our office energy use.