Lighting less to achieve net zero
The energy was high, the crowds were large, and the product was innovative and fresh at the 2009 Lightfair International (LFI) conference held in New York. LFI is the world's largest architectural and commercial lighting trade show and conference, and the 20th annual show was held in May 2009 with a record-breaking attendee registration of more than 23,000 industry professionals and conference participants.
Energy efficiency was a major theme at the event. Many manufacturers presented sustainable designs made possible with innovative luminaires. There were also lighting-related educational sessions and seminars on "zero energy buildings" (ZEB) and zero carbon footprint.
This trend in energy efficiency has been encouraged by the federal government in state stimulus plans as well as new energy codes and lighting standards. (See " New lighting standards for 2012 .") The U.S. Dept. of Energy (DOE) has established an aggressive goal to create the technology and knowledge base for cost-effective commercial ZEB by 2025.
Many groups refer to ZEB, but they can be defined in vastly different ways depending on the boundary and the metric. Different definitions may be appropriate for certain project goals and values. For example, building owners typically care about energy costs. Organizations like DOE are concerned with national energy numbers, and typically are interested in primary or source energy. A building designer may be interested in site energy use for energy code requirements. Finally, those who are concerned about pollution from power plants and the burning of fossil fuels may be interested in reducing emissions. Four commonly used definitions for ZEB are: net zero energy costs, net zero source energy, net zero site energy, and net zero energy emissions.
As building systems designers, we are concerned more with site energy use for energy code requirements. How can I reduce this site energy use through efficient lighting? The answer is: by using low-energy building technologies and energy-saving practices.
Building engineers can use energy-efficient building techniques by properly orienting the building on the site to receive daylight more efficiently, maximizing ceiling height, using light-colored surfaces as reflectors, avoiding high-contrast surfaces, using shading devices, and placing electric lighting parallel to windows. Building systems designers also should consider using high-efficacy sources and high-efficiency luminaires. Other basic practices to conserve energy include turning off the lights when they're not in use, grouping like tasks, placing light fixtures close to tasks, and not lighting noncritical areas.
Just imagine working without light! We typically have so much light at our disposal, it's hard to imagine going about our daily routines with less light. However, it is possible, and it is exactly what we should do now. Next time, really think about light before you turn the switch on.
Haran is an electrical and lighting systems consultant in the Chicago area. He is also an advisory member of the IESNA sustainable lighting committee.
New lighting standards for 2012
In July 2009, President Barack Obama and the U.S. Dept. of Energy (DOE) announced plans to increase energy efficiency by changing the nation's lighting standards. The final rule does not take effect until 2012, but several standard levels are being adjusted currently.
These federal lighting standards are designed to ensure that new, more efficient lighting technologies are phased into the marketplace. Obama will support legislation that will phase out traditional incandescent light bulbs by 2014. The DOE states that 7% of all energy used in the United States comes from lighting, but with the new standards, the country could save $4 billion a year in energy costs.