Lighting the Way
- By Kevin Orth
- February 1st, 2009
A distressing fact is facing education across the country. Primary and secondary schools are spending a staggering $6B annually on energy — more than is spent on textbooks and computers combined. This equation doesn’t make sense; surely there are ways to lower schools’ energy costs, allowing more money to be spent on educating children.
According to the U.S. Green Building Council (USGBC) Build Green Schools Website, “…if a green school saved $100,000 per year in operational costs, that's roughly enough to hire two new teachers, buy 200 new computers, or purchase 5,000 new textbooks.” Additionally, the USGBC has determined that if all new school construction and school renovations went green starting today, energy savings alone would total $20B over the next 10 years.
I recently read what the California Energy Commission has to say about conserving energy in the state’s schools, especially since it is the nation’s largest school system. California schools spend $700M a year — nearly three percent of their total budget — on energy. By employing energy efficiency in the state’s schools, the system could cut energy bills by 20 to 40 percent, leaving money for other educational priorities.
But what can schools implement now — to already existing facilities — that will lower their energy costs and move them toward being green? While few schools in the United States are officially labeled "green" construction, there are many smaller things that can make a school "greener," or more environmentally friendly. The U.S. Department of Energy (DOE) has calculated that lighting in institutional facilities, including schools, can consume up to one-third of a building’s total energy cost. Typically, lighting is viewed as a fixed expense but with the tremendous advances in technology and engineering, and given this statistic this line item needs closer examination.
LED Luminaires Lead the Way
With compact size, great efficiency and long life, Light Emitting Diode (LED) technology is viable from a performance and economic standpoint moving it into mainstream lighting applications. By and large, LEDs were thought about only for aesthetic uses. But engineering and technological advances have improved LED luminaires’ output, and it is possible to use high-efficiency LED lighting for general lighting applications for interior and exterior spaces in schools. LEDs are a more cost-effective and energy-efficient alternative to high intensity sources such as high-pressure sodium and metal halide.
LEDs have been around for over 40 years. The small digital devices can be used to produce millions of different colors and brightness levels of light, but they use significantly less energy than traditional lighting methods.
Within the past few years, LED technology has advanced to the level where they can match or outperform HID light sources. Previously, conventional approaches to developing general illumination LEDs often involved retrofitting existing fixtures to house new LED technology. Many early attempts simply used traditional standards and housings, resulting in poor performance, inefficient lighting, and lower fixture life. Be wary of this approach and look for products specifically designed around LEDs.
Due to their long life, LEDs are virtually maintenance free, and the energy savings is dramatic. For example, replacing a 400-W, high-pressure sodium parking lot fixture with an LED luminaire provides between 40 to 60 percent energy savings. LEDs also re-strike instantly after a power interruption and can be controlled with occupancy sensors to offer even greater energy savings.
Additionally, an LED does not burn out like a standard lamp, so individual diodes do not need to be replaced. Instead, they gradually produce lower output levels over a very long time. In fact, well-designed fixtures can last over 100,000 hours. If one LED fails, it does not produce a complete fixture outage.
LEDs don’t require any special equipment or drivers to deal with temperature conditions. Their performance is unaffected down to a negative 40 degrees Celsius. This allows for instant on/off control without specially designed circuitry.
In real world applications, LEDs typically outlast metal halide sources by a minimum of five to one. This longevity alone translates into significant energy savings and greatly reduced maintenance. Additionally, LED lighting for general outdoor use provides the following.
- Durability: LEDs are solid state devices containing no moving parts, no filaments, or fragile glass to break, eliminating the risk of damage during transportation, installation, and operation, even in the toughest environments. And unlike conventional light sources, LEDs are not subject to sudden failure or burnout.
- Longer life span: an LED lasts vastly longer than incandescent, fluorescent, or HID lamp sources.
- Green: LEDs are considered sustainable because they decrease the need for additional power plants that cause the release of CO2 into the atmosphere.
The DOE has heralded LEDs as the future of lighting because LEDs have an extremely long life span when compared to incandescent lighting — in many cases lasting 20 times longer. In addition, LEDs consume considerably less energy and are clean burning, thus reducing carbon emissions significantly.
The cost paradigm for LED is different than HID due to their slightly higher initial cost. However, that higher initial cost is being offset by accelerating ROI curves thanks to less energy consumption and lower maintenance costs.
Brighter Light, Increased Safety
With energy efficient LEDs, the light perceived is highly visible to the human eye and people can see much further and easier in the dark. This type of lighting allows better sight and color recognition using considerably less energy. Color recognition in particular is an important factor for people’s sense of safety. At night, the human eye sees using rod-shaped photoreceptors, while in the daytime it uses cone-shaped receptors. The cones are much more sensitive to light and therefore need far less light to see well. Traditional street lighting tries to imitate daylight, allowing us to experience good vision when under the streetlight. The major disadvantage, however, is that when it is dark beyond the range of the light source, the eyes constantly have to readjust to the dark and then to the light, and then to the dark again, and so on. With LED lighting our eyes perceive the light differently. We do not only see the tunnel of light, but also much of the surroundings. This gives a stronger sense of safety. This type of lighting is therefore not only energy-efficient and cost-effective, but also safer.
In 2007, a survey was administered by Mindwave Research, Inc. of Austin, TX, a leading technology market research firm, on behalf of Cree, Inc. This survey measured overall satisfaction with the parking garage, opinions about garage cleanliness, and lighting quality, and feelings of safety before and after the lighting was changed to LED luminaires.
The results indicated a very significant improvement in the customers’ feelings of safety, opinions about the lighting quality, and satisfaction with the overall garage.
Effectiveness relates to the luminaire’s performance. Light that is disbursed in all angles creates light pollution, either as skyglow, which is light directed upward, or light trespass, which is light falling into unwanted spaces such as street or parking lot light falling into a bedroom. The International Dark-Sky Association estimates that 30 percent of all outdoor lighting is directed skyward and is wasting $1.5B per year in the United States alone. Effective lighting design means putting light where it is wanted and needed and eliminating light where it is not.
The Prairie School
The Prairie School in Racine, WI, recently improved lighting quality, reduced maintenance costs, and realized a 53 percent energy savings through the installation of LED area lights in the main parking lot. School officials were impressed with the astounding visual impact of the new lighting and the dramatic savings, both in maintenance and energy costs. Taking into account the over 50,000 hours of fixture life, the facility will be looking forward to over 16 years of maintenance-free operation.
This beautiful, 1965 Frank Lloyd Wright-inspired, K-12 school is well established within the community. Maintaining the contemporary design of the campus while blending with the wooded, rural setting was an important consideration in the installation of new outdoor lighting; the low profile design of the area lights successfully met those criteria.
William. H. Mark Murphy, headmaster and president of The Prairie School comments, “We’re not only happy with the impressive light levels of the LED fixtures, but we’re also looking forward to realizing the cost savings on our utility bills from the reduced energy usage.”
Due to the success of the outdoor luminaires, Prairie School is evaluating interior LED luminaires in a classroom and a hallway.
Recently, mayors across the country formed the Mayors’ Alliance for Green Schools, a coalition of mayors seeking to, “strategically harness the leadership and creativity of mayors across the country to promote the benefits of green schools in their communities.” Developed in partnership with the USGBC, the Alliance will work to accelerate implementation of programs supporting the 2007 U.S. Conference of Mayors resolution calling for green schools for all children within a generation. This new Alliance dovetails perfectly with the push by recent states’ and municipalities’ mandates. In addition to California, other municipalities are weighing in with a mix of mandates and incentives. For example, Washington, D.C. became the first major U.S. city to require large, private non-residential buildings to be environmentally friendly.
Boston also wrote green building requirements into its zoning code in 2006. In Chicago, Mayor Richard M. Daley has laid out a goal to make Chicago the greenest city in the U.S. These mandates and incentives provide an excellent catalyst for LED luminaire engineers and manufacturers to continually improve the technology and product designs.
According to the latest U.S. Census Bureau (2006-2007), there are 95,615 public elementary and secondary schools and 29,273 private elementary and secondary schools in this country. Imagine the amount of money that could be redirected toward educating children, hiring more teachers, and buying necessary classroom materials if an energy efficiency program was implemented.
The DOE reports that states and local agencies are planning to invest more than $60B in the next three years to build or renovate schools. Now is the time for school districts, government and community leaders, and parents to recognize that sustainable products, such as LED luminaires, are a catalyst to significant improvements in energy efficiency in the nation's K-12 schools.
Kevin Orth is director of Sales for BetaLED and may be reached at Kevin_orth@beta-kramer.com or 262/884-3132.