Streetlight Retrofits Will Wait

By Kim Siebert MacPhail

Moving to energy-saving LED streetlights would save the town approximately $44,816 a year, according to Public Works Director Rich Warrington. The problem is that the initial cost for the conversion project carries an estimated price tag of $1,048,845, including replacement of the 50-60 year-old “mast arms” from which the lights are suspended. Even after subtracting both the cost for the mast arms ($225,750) and the expected NSTAR rebate ($52,060), the project cost is only reduced to $771,034, which translates to a disappointingly longer-than-expected 17 year payback time frame.

Warrington told the Capital Expenditures Committee on Wednesday night that a recent inventory shows Bedford with a total of 1,505 streetlights. About 22 of these lights are still the “old style” mercury vapor lights that were overlooked in an upgrade to the current technology— high- pressure sodium—15 years ago.

“The vast majority of our lights, the typical lights you’d see in a subdivision—4,000 lumens, high-pressure sodium—were, up until a couple of years ago , the answer for [the] most efficient type of street lighting,” Warrington said. “They still have life in them, but with the LED light improving and coming down in price, it’s time to start looking at upgrading these.

“As it stands right now, we have almost 142,000 watts when the streetlights go on,” he continued. “By converting these to LEDs, we reduce that to 52,541 watts. This results in a savings of $44,816 a year, based on a cost of $0.12912 a kilowatt hour, if we converted them.”

The new LED fixture cost for the most common kind of streetlight is $360 per unit.Fixture replacement costs for the 98 streetlights of two other types is higher, $425 and $600, respectively. Each mast arm is $150 and the labor cost for conversion per streetlight is at least $175.

Whether or not the streetlights are upgraded, Warrington says the mast arms are approaching the end of their useful lives.

“Mast arm replacements are long overdue,” he said. “The galvanizing on the steel is worn away; they’re rusting. They’re starting to fail pretty badly. Inherent in this design, unfortunately, is the need to replace that mast arm. It adds a little on the labor side, raises the unit price up.”

But even after removing the cost of the mast arms and calculating the utility company rebate, Warrington said the payback period he expected to be 7 to 8 years turned out to be 17 years instead.

“This is a lot higher than I expected,” Warrington said. “We’re using the best numbers we can find: we’re not using the cheapest, and by no means did we use the most expensive [replacement fixtures.]

“There might be another $10,000 savings a year in maintenance costs [over the $44,816 savings in energy costs] because the LED igniter [has a longer useful life than the current model]” he added.

After some discussion, the Capital Expenditures Committee decided that the streetlight retrofitting project should remain on hold so that the numbers can become firmer, the prices can come down, and rebates and potential Green Communities grants can be secured to help pay for the high cost of conversion.