Federal Stimulus Funding Discounts Cost of LED Traffic Lights

The city plans to replace 55,000 green - and yellow - energy-hogging incandescent traffic signals with efficient light-emitting diodes, or LEDs.  When the project is done in two years, every traffic light at the city's 2,800 signaled intersections will be equipped with the low-wattage LEDs. (The red lights were switched to LEDs about 10 years ago.)

Philadelphia transportation and utility officials believe they can accomplish the switch at a steep discount, thanks to federal stimulus money, combined with state-required Peco Energy Co. subsidies designed to encourage energy conservation. Traffic engineers across the region are furiously writing grants to take advantage of government-inspired energy-conservation promotions.
 

LED technology has been around for decades, but the devices have received much attention lately as their price has come down and they have become more affordable for household use. Joseph M. Doyle, Philadelphia's chief traffic engineer, said the city converted all its red lights to LEDs in 1998. Red was the only color available then.

According to Peco, a typical 12-inch red incandescent signal lamp is rated at 150 watts and consumes $88.46 in electricity per year. A comparable LED uses 11 watts and consumes $6.49 in power. (Red traffic signals are on longer than green or amber lights, so they offer the greatest savings.)

The cost of the LED units would be supported by Peco, which included a proposal to subsidize the upgraded traffic signals in a sweeping $342 million energy-conservation plan filed last month with state regulators. State law compels electric utilities to drive consumption down 3 percent by 2013.

Municipalities began using LEDs in traffic signals in the 1990s. Peco spokeswoman Cathy Engel said that about half the region's 165,000 traffic lights were now LEDs.

Some municipalities could not wait for the incentives.

Nether Providence, Delaware County, spent $8,208 last year to convert its 15 signaled intersections to LEDs. Since then, its monthly bill for traffic signals has decreased from $860 to $143, said David Director, chairman of the township's energy committee.

The new lamps paid for themselves in a year, Director said.

SOURCE:  Philly.com