Controlled Environments, Controlled Costs
We all know that the most efficient light bulb—from an energy standpoint—is the one that stays turned off. The same can be said for air-conditioning units. Unfortunately, our modern lifestyles require us to flip that switch and turn that thermostat. So, if indoor environments impact energy use, how do we control those indoor environments?
Those of us concerned with energy efficiency and reliability know that lighting and HVAC can account for a vast portion of any facility’s energy costs. Most of the time, human nature and outdated technology conspire to undermine attempts to reduce energy use—employees leave the lights on, the air conditioner rumbles and cools an empty building, and the heater kicks in while the sun is shining.
There’s a direct relationship between fixtures and energy management. The latest innovations allow us to micromanage the duration, quality, and intensity of our lighting and HVAC. And while the cost can sometimes seem daunting, the truth is that for a relatively small investment at the outset, huge savings can be reaped as energy bills diminish.
And these savings are not insignificant.
According to a new report released by the Department of Energy’s Pacific Northwest National Laboratory (PNNL), US commercial buildings could save an average of 38% on heating and cooling if they employed efficient HVAC systems. Although the report found that “individual control strategies have different degrees of impact on energy and cost savings,” ultimately, in all cases, retrofitted HVAC units resulted in annual savings—up to 55 trillion BTUs per year at a 30% savings rate. At that level, the report states, the energy savings are “equivalent to removing over 16 coal-powered (200-MW each) power plants.”
The report’s findings were based on computer modeling and simulation of energy usage across a wide variety of commercial buildings in different settings and climates.
“The potential savings from adding advanced controls to existing packaged air conditioners with gas furnaces is enormous,” advised Srinivas Katipamula, the PNNL engineer who led the study, in a statement about the report’s findings.
Reiterating Katipamula’s sentiments, US Energy Secretary Steven Chu says, “Investing in an American economy that is built to last includes taking advantage of all of America’s energy resources while working to improve efficiency. By making heating, ventilation, and air-conditioning systems in buildings more energy-efficient, American businesses can save a significant amount of money by saving energy.”
Savings can also be found in efficient lighting—particularly when advanced lighting control systems are utilized. Lighting control systems are flexible, offering a variety of choices that can adapt to specific environments. There are standalone occupancy sensors and dimming switches, while ore complex installations include digital lumen readings, programmable dimming, and automatic shutoffs. Relay lighting control panels can incorporate lighting schedules that work in tandem with occupancy sensors and photocells to further increase efficiency with precise lighting timetables.
According to a 2012 DOE report, lighting accounts for about 700 terawatt-hours (TWh), or “almost 19% of electricity produced in the United States.” Additionally, the New Buildings Institute has determined that advanced lighting controls can generate up to 50% lighting energy savings in existing buildings.
But it’s not just the switch from incandescents that’s spurring change. In 2004 ASHRAE adopted a national standard defining the minimum requirements for lighting controls (ASHRAE 90.1-2004), establishing a baseline and creating an industry standard. Since that time, study after study has proven the value of these lighting systems. The Canadian Lighting Controls Association, for example, conducted a one-year study of 90 office workers, which revealed that the use of occupancy sensors, daylight harvesting, and individual dimming controls could produce an average savings of 47%.
The US Energy Independence and Security Act of 2007 calls for a net-zero target of 50% of commercial buildings by 2040—and HVAC and lighting efficiencies are essential to achieving that goal. And as part of that effort, the DOE launched the Net-Zero Energy Commercial Buildings Initiative in 2009, and the US General Services Administration has set a carbon neutrality target by 2030.
And don’t discount the incentives and tax breaks associated with increased energy efficiency. As just one example, the Energy Policy Act (EPACT) of 2005 provides tax incentives for commercial buildings that reach or exceed 50% less than ASHRAE’s 90.1-2001 performance standards. In 2008 as part of the ARRA stimulus package, the EPACT legislation was extended for five years. Under the program, commercial buildings that fit the EPACT criteria can realize a tax deduction of $1.80 per square foot as a result of energy-efficient lighting, HVAC, and hot water systems.
The goals are already in place . . . what we need now is implementation.
Author's Bio: Elizabeth Cutright is the Editor of Distributed Energy magazine and Water Efficiency magazine