As a result, red traffic lights in more than 100 California cities have been converted from incandescent bulbs to new light-emitting diode (LED) devices. As part of the conversion process, Caltrans developed performance standards that supplemented the Institute of Traffic Engineering national LED specifications. The Caltrans standards now are being widely used by California cities to support their programs to convert to the LED technology.

The red light conversion initiative is part of the PowerSaving Partnership Program administered by Pacific Gas & Electric Company (PG&E). This unique program was designed to reduce energy demand and therefore avoid building new power plants.

The energy saving program began in July 1996 when PG&E selected Electro-Test Inc. from a field of 36 energy service companies to research and implement performance-based energy conservation programs.

"As one of seven companies we chose to implement our energy saving initiative, Electro-Test was awarded two contracts that required a three-year research segment. During that time they identified Caltrans as a potential customer that would produce specific environmental and business benefits through better control of energy usage and costs," said Charles Maroon, program manager for PG&E’s PowerSaving Partners Program.

To date, Caltrans has upgraded the traffic lights at over 2,000 highway traffic intersections in the PG&E service area. The upgrades save 6.5 million kilowatt hours of electricity each year and $645,000 in annual utility costs. Statewide conversion is expected to save nearly $2.5 million per year in energy costs.

"To put the current savings into perspective, 6.5 million kilowatt hours is equivalent to about the same amount of power it takes to operate 650 homes year round," said Jay Raggio, manager of energy services, Electro-Test, Inc.

"This level of savings would not have been possible without Electro-Test. From delivering an extremely high level of technical expertise to contributing to the financing of the project’s equipment, they have helped to create a model program for the rest of the country," said Maroon.

"The Caltrans project has several benefits. Since the new equipment lasts seven to ten years longer than traditional bulbs, it uses less landfill space. LED lights also create fewer zinc and mercury deposits, which is vitally important to the environment. It reduces the overall costs to the utility and to the customer in the form of less usage. It increases the performance of the traffic signals to enhance public safety. Rolling brownouts and blackouts are becoming serious problems and conservation programs like this directly address those issues," added Maroon.

As an additional incentive to introduce Caltrans to The PowerSavings Partners Program, Electro-Test offered to pay Caltrans two cents for every kilowatt-hour saved during the first six years of the project. Electro-Test recently made good on that incentive by presenting Caltrans with a check in the amount of $707,000.

Caltrans proved to be an excellent choice for an LED initiative since it was the first major government agency to conduct a large scale LED field test. In 1995, The U.S. Department of Energy recognized those efforts with a national energy conservation award for the initial test bed, which included 2,300 fixtures in Fresno, California.

According to Steve Prey, energy conservation coordinator, Caltrans, "We had begun a statewide program to replace existing traffic signal lights with LED technology that could save taxpayers more than $4 million a year in electric bills. For our PG&E-served intersections we worked with Electro-Test since they were executing one of the PG&E energy conservation contracts. They did a fantastic job of documenting energy patterns that lead us to revamping several aspects of how we handled traffic light conversions."

An integral part of energy savings was achieved using a light-emitting diode (LED), a semiconductor device using solid-state electronics to create light. Traditional traffic lights are 12" in diameter and use a 150-watt incandescent lamp, which releases 75% of the energy in the form of heat. Conversely, an equivalent 12" LED traffic light is 8" in diameter and uses only 12 watts of power. It emits little heat since it is solid-state.

The lifecycle of the LED light ranges from seven to ten years compared to one year for incandescent lights. According to Electro-Test, converting traffic lights to LED technology saves $470 per intersection per year. Each 12" LED traffic signal initially had cost $120 but because of the major purchases being made by Caltrans the costs have being going steadily downwards and they are now less than $100.

In addition to energy conservation and utility savings, LED lights dramatically improve public safety because of the affordable battery back-up option. During a power outage, battery back-ups enable a red light to flash as opposed to having a non-functioning signal.

"The LEDs allow us to go to flashing rate at a cost of $1,000 per intersection versus $60,000 per intersection with incandescent bulbs," said Prey. According to Caltrans' research that began in 1993, traffic accidents have been reduced by 90% in certain high-risk intersections due to battery back-ups.

In addition to the LED conversion efforts in California, Electro-Test is currently involved in similar performance-based incentive programs elsewhere in the nation. Texas has been targeted for a program that began in 2001.

Electro-Test, Inc. is the leading independent electrical and mechanical testing and engineering service company in the United States. A wholly owned subsidiary of Emerson Electric Company, it serves more than 15,000 customers through 34 strategically located domestic service centers. Electro-Test employees 500 engineers, technicians and support professionals who provide field engineering services, technical services and technical training to major energy users worldwide.

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