A Bright Future Using LEDs
When the ball dropped in New York City’s Times Square on New Year’s Eve, it was not just signaling the beginning of a new year. It was signaling the beginning of a new era of lighting technology.
On Jan. 1, 2011, an energy-efficient lighting law in California made the traditional 100-watt incandescent light bulb illegal.
A similar federal law, the Energy Independence and Security Act (EISA) of 2007 (Public Law 110-140), goes into effect on Jan. 1, 2012. Its strict energy efficiency requirements for lighting effectively ban the manufacture or import of the “general-service” 100-watt, incandescent bulb with additional efficiency requirements affecting a wide variety of additional lighting.
By Jan. 1, 2013, 75-watt general-service incandescent bulbs will be phased out, followed by 60-watt and 40-watt bulbs by Jan. 1, 2014.
As a result, individual consumers and procurement professionals across the country are examining new lighting technologies such as light emitting diodes (LEDs).
What are LEDs?
LEDs are a semiconductor-based light source more comparable to a computer circuit than to the traditional gas-filled, filament-based incandescent light bulb Thomas Edison perfected back in 1879.
LEDs were prohibitively expensive when invented in 1962. Many of us first experienced LED lights as the high-tech red glow in early calculator displays or as the red indicator light on stereos and other early electronics. LEDs now illuminate cell phones, computer monitors, laptops, televisions and more.
Originally limited to a narrow band of colors, LED technology has improved significantly so that the full spectrum of colors can be produced reliably. The improved color technology, along with steep reductions in manufacturing costs, are making LEDs a practical and affordable specialty and general-purpose lighting solution.
LED quality and price have reached a point where many home improvement centers and other large retailers are routinely stocking LED lights for a variety of uses, including as a replacement for the 100-watt incandescent bulb. Professional purchasers and building managers are taking advantage of volume purchases to further lower costs.
Government purchasing drives innovation
Long before LED light bulbs began appearing on retail shelves, government purchasers were taking advantage of the new technology to reduce operating and maintenance costs for things such as building exit signs and traffic signals. Government purchasers are also switching to LEDs for street lights and general building lighting needs.
Exit signs. LED exit signs can reduce electricity consumption 95 percent versus more energy-demanding incandescent exit signs. With a life expectancy of 50,000 to 200,000 hours (5.5 to 23 years), they can also significantly reduce maintenance costs when compared to incandescent bulbs that must be replaced every six months. According to the U.S. Environmental Protection Agency, each LED exit sign also prevents the release of half a ton of global-warming pollution annually when compared to traditional incandescent technologies.
Traffic signals. LED traffic signal bulbs are now the industry standard for new traffic lights. Converting traffic signals from traditional incandescent bulbs to LEDs can generate significant financial and environmental benefits because they use 93 percent less electricity. According to one study, if every traffic signal in the United States converted from incandescent to LED bulbs, it would save 3 billion kilowatt-hours of electricity. The environmental benefits would be the equivalent of removing more than 350,000 vehicles from the road. The current cost of LED traffic bulbs remains significantly higher than incandescent alternatives, but the energy savings and maintenance costs produce significant return on investment. Incandescent bulbs must be replaced every one or two years while LED bulbs last five to 10 years. According to the Responsible Purchasing Network, the payback time for an LED traffic signal retrofit is two years with a total return on investment of 200 percent.
Cities making the conversion
Cities across the United States have converted to LED traffic signals and are benefiting from substantial cost and environmental savings. Examples include:
Phoenix, Ariz. A contract to replace traffic signal lights at 335 intersections was issued in early 2011, with a proposed Phase II to replace an additional 525 intersections. The project is expected to reduce emissions by 2,517 tons of carbon dioxide and other global warming pollutants, the equivalent of removing 475 cars from the road or powering 408 homes each year.
Denver, Colo. It began retrofitting signals in 1996 and has replaced more than 20,500 traffic signals. It estimates annual savings of $430,000 resulting from reduced electricity and maintenance costs. The retrofits also avoid 5,300 metric tons of carbon dioxide (global warming) emissions.
Salt Lake City, Utah. Although the number of traffic signals has increased 50 percent since Salt Lake City began its retrofit program in 2001, the annual energy use has still declined by 56 percent. The city estimates savings of $115,000 per year resulting from its use of LED traffic signals.
Street and parking lot lights
Street and parking lot lights are another application in which LED bulbs offer significant cost savings. The U.S. Department of Energy (DOE) estimates that if the United States replaces all of its roadway high-pressure sodium (HPS) lights with LED, it will reduce electricity demand by 8.1 trillion watt-hours and avoid 5.7 million metric tons of carbon dioxide (global warming) emissions, the equivalent of removing 934,000 cars from the road.
Electricity use can be cut by 35 to 75 percent compared to HPS or metal halide (MH) alternatives. The larger financial benefit, however, results from reduced maintenance costs with LED lamps having estimated lifetimes of 50,000 to 100,000 hours versus 8,000 to 24,000 for HPS or MH alternatives. Ann Arbor, Mich., reported that maintenance savings alone make LED fixtures less expensive on a life cycle basis than conventional fixtures. Los Angeles also reports that its LED street lights are more durable and damage-resistant, which further reduces maintenance costs.
The upfront cost of replacing street lamps is a continuing challenge because the entire assembly must be replaced. Prices are, however, declining rapidly. A 2008 DOE study reported that LED street lamp costs are decreasing at a rate of 20 percent annually, while light output per unit is increasing 35 percent annually.
One manufacturer recently bragged at a trade show that their street lamp products today are “three to four times brighter, twice as efficient, and one-fifth the cost” of their first-generation product.
Many cities, however, are not waiting for further improvements. They see financial benefits to converting now. Los Angeles began a $57 million, five-year project in 2009 to replace 140,000 existing street lights with LEDs. When complete, the project should save $10 million annually in lower energy and maintenance costs while lowering carbon dioxide (global warming) emissions by 40,500 tons per year with an expected seven year payback.
Other cities are working with LED manufacturers and energy savings contractors (ESCOs) who are offering generous financing to transition to LED technologies. More than 30 cities requested federal stimulus money for LED lighting projects. San Jose, Calif., for example, used $2 million in energy efficiency stimulus funding to install 1,500 LED street lamps.
LEDs are rapidly appearing as general-purpose lighting in office buildings and homes. LED lighting products have been designed to replace fluorescent tube lighting without replacing ballasts. They are being used as decorative lighting in numerous buildings. With the price of LED bulbs falling rapidly, they are even appearing in the desk lamps on purchasers’ desks.
According to one recent report, government and institutional spending on LED lighting for buildings will rise to $100 million in 2013, up from $65 million in 2008.
The environmental and financial benefits of using LEDs for general purpose lighting are comparable to the benefits for the specialty applications described above. An additional benefit for interior building use is that LEDs generate significantly less heat, thereby reducing stress on a building’s air conditioning system.
Among the interior LED building lighting projects under way:
- A section of the Pentagon undergoing renovation is installing 4,200 LED light fixtures.
- The historic Rotunda building at the Los Angeles County Natural History Museum upgraded its incandescent light fixtures with custom-made LED systems to keep with the historic look of the building while generating significant energy savings.
- Cold Spring, N.Y., is replacing metal halide lamps in its water treatment facility with LEDs using significantly less energy. They are also replacing fluorescent tube lighting with LED replacement lamps.
- The Pasadena, Calif., library upgraded 30 historic pendant lighting fixtures to significantly improve energy efficiency while maintaining the ambiance provided by the historic fixtures. Energy use was cut 90 percent, saving thousands of dollars for the library.
- Virginia Beach, Va., is upgrading the interior and exterior lighting at its Convention and Visitors Bureau. The changes include recessed LED downlights and track lighting, LED exit signs, interior and exterior security lighting, and lights in the parking lot.
As with any significant purchase, purchasing professionals must work with the specifiers to ensure the LED lighting technologies being considered are being accurately compared. The Responsible Purchasing Network, Environmental Protection Agency and other experts highlight the following areas to consider:
Lumen output. A measure of how much light the bulb produces. Lumen output should remain constant over time, only decreasing towards the end of its rated lifetime.
Power consumption (efficacy). How much electricity is required to power the bulb (measured in lumens per watt)? What kind of independent verification or certification is offered to substantiate the lumens per watt claim? Compare the results of testing to the IESNA-LM79 standard, which is required as part of the Energy Star program for lighting products. Test results are summarized on the Department of Energy’s Lighting Facts Label.
Color quality. The color should be consistent over the rated lifetime of the bulb measured by the correlated color temperature (the “warmness” or “coolness” of the light) and the color-rendering index (to determine how faithfully light reproduces specific colors).
Safety considerations. Have the appropriate Underwriters Laboratories (UL) safety, including UL870, or other safety standards been met?
Performance guarantees. How long are the bulbs covered under warranty? What is covered? What level of light quality and output does the warranty guarantee?
Certifications. Has the LED been certified by an independent laboratory as meeting Energy Star, DOE CALiPER, NVLAP, UL, and other necessary standards?
Financial and environmental savings
The US Department of Energy estimates that over the next 20 years LED lighting in the United States can:
- Create savings of $265 billion
- Reduce electricity consumption for lighting by 33 percent
- Negate the need for 40 new power plants
An LED-powered New Year’s Eve
Like the future of the country, the world-famous Times Square Ball is lit with advanced light emitting diode (LED) technology.
The 32,256 LEDs lighting the ball are each digitally controlled and capable of producing 16 million different colors that can be used to produce patterns and images.
More important to cost-conscious procurement officials, the LED lights use only about 12 percent of the electricity that would have been used to power it with traditional lighting technology. The LED lights have a rated life expectancy of 30,000 hours (3.4 years of continuous use) versus the approximately 1,000 hours (1.4 months) for traditional incandescent and halogen lights, saving significant labor costs to replace light bulbs.
The LEDs are lead- and mercury-free, meeting European RoHS environmental standards, which can mean additional cost savings through reduced hazardous disposal costs.
DOE CALiPER certification
The US Department of Energy (DOE) created the Commercially Available LED Product Evaluation and Reporting (CALiPER) program to measure and evaluate LED lighting using third party testing laboratories like Underwriters Laboratories (UL). See www1.eere.energy.gov/buildings/ssl/about_caliper.html.
Bright future ahead
LEDs are beginning to appear on consumer retail shelves in part because the large volume government purchases helped drive LED costs down and quality up. As a result, more and more governments and consumers are shifting to LEDs, saving money, reducing energy consumption and improving their environmental performance. Government purchasing will continue to influence the unfolding LED market and help determine how bright the future will be.
Responsible Purchasing Network, www.responsiblepurchasing.net – Produced a Responsible Purchasing Guide for LED Exit Signs, Street Lights, and Traffic Signals that includes recommended purchasing specifications. It also includes calculators to help determine cost savings and payback periods.
US Department of Energy CALiPER Program, www1.eere.energy.gov/buildings/ssl/about_caliper.html – Establishes standards and testing protocols for LEDs.
US Department of Energy Municipal Solid-State Street Light Consortium, www1.eere.energy.gov/buildings/ssl/consortium.html – Evaluates new technologies, shares best practices, and provides additional resources.
Energy Star, www.energystar.gov – Establishes LED energy-efficiency and performance standards for LEDs.
Underwriters Laboratories, www.ul.com – Establishes LED safety and performance standards and tests products to ensure compliance to energy-efficiency, safety and performance standards.
About the Author
Scot Case has been researching and promoting responsible purchasing issues for 17 years. He is market development director for UL Environment. Contact him via e-mail at email@example.com or in Reading, PA, at 610-779-3770.