City Hall to see green lighting after years of energy waste

The sight of Boston City Hall wastefully lit up like a Christmas tree at night will soon be a thing of the past. Building officials say they have figured out a better way to turn out the lights.

Forty years after the opening of the concrete landmark, built in the Brutalist architectural style, City Hall technicians are installing a $667,000 system of motion, sound, and heat sensors so the lights on each of its nine floors will be illuminated only when the rooms are in use.

"It has always been a sore spot for me," Michael Galvin, chief of property management for the city, said of the lighting problem.

City councilors have often complained that, while they preach energy efficiency in their neighborhoods, they cannot shut off the lights in their own fifth-floor offices when they leave for the day. Mayor Thomas M. Menino persuaded owners of 34 downtown skyscrapers this year to turn out the lights on higher floors at night, but City Hall remained a glaring example of waste.

The problem lies in antiquated wiring. Replacement parts for the system are not available, officials said.

Over the years, when the connection between a manual switch and a light fixture malfunctioned, building officials bypassed the switch and linked the light directly to one of 57 circuit breakers in the building. That means that when a worker remains at night, an entire floor may light up for the sake of illuminating a single room.

The city was spurred to fix the problem by an NStar incentive program for commercial customers who reduce energy use. When the installation is complete, probably by March, the city will receive a one-time payment of $210,000 from NStar for energy efficiency. The city expects to save an additional $189,000 a year on energy, so the investment should pay for itself within a few years, officials said.

In addition to the motion detectors, lights in the building also will be computerized for the first time. Lighting in some larger rooms, like the City Council chambers, will be placed on a timer.

Menino has hesitated to approve much spending on upgrades to City Hall, because he would prefer to abandon the building in favor of a new City Hall on the South Boston Waterfront. But Galvin said a move could not happen in less than five years, so the city would realize savings from the upgrade before moving the seat of city government.

"You have to look at the payback period," Galvin said. "Whatever happens with the property, whether we stay, we go, whatever - was it right to do? And the answer is, yes."

John Drake can be reached at jdrake@globe.com.