U.S. commercial buildings could cut energy use by 29 percent on average by taking full advantage of controls technology and implementing a few other base energy-efficiency measures, according to a new study from the Pacific Northwest National Laboratory. Commercial buildings account for 20 percent of U.S. energy use and produce 50 percent or more of a city’s greenhouse gas emissions (75 percent in New York). If we want “smart cities” to be more than just a catchy phrase, this is an opportunity we must seize.
The trouble is, the opportunity has been sitting there for a very long time. The Clinton Foundation announced a multibillion-dollar initiative to cut urban energy in 2007, on the same day the National Academy of Sciences, along with the scientific academies of 12 other countries, called on world leaders to address global warming by increasing energy efficiency. And yet, building energy use has risen over the past five years in even the most efficiency-conscious cities, based on an analysis of American Council for an Energy-Efficient Economy data. What gives?
Part of the problem is flat-out lack of action. The other part is the persistent problem of performance drift — buildings and building systems should be highly efficient, but performance deteriorates rapidly or never matches the model. Culprits such as ineffective controls and a mismatch between design assumptions and building occupant behaviors get a lot of (deserved) scrutiny. But to really solve the problem, we need to rethink the metrics we use to measure energy design for smart buildings.