The 50-year-old Milwaukee Public Museum building exterior is getting a high-tech makeover, including a sleek bank of solar panels that will grace the south wall.
An entire wall facing W. Wells St. will be covered with shiny black photovoltaic panels, replacing heavy marble slabs that were beginning to sag, crack and in a few instances, shed small pieces.
"We were starting to see chips of marble come off along some of the juncture points," said Ellen Censky, a senior vice president of the museum. "The issue is the marble is starting to crumble and chip away."
The slow process of removing the 234 marble panels has been underway for about a month. Each 31/2-by-5-foot panel weighs a ton and must be carefully detached from metal frame clips holding it in place. A crane then lifts the panels one-by-one from the building.
It's often tough to separate the panels from their frames and the concrete block wall the panels are attached to, requiring noisy drilling and chipping of mortar, Censky said.
Because of fears that chunks of marble could fall during the panels' removal, the adjacent Puelicher Butterfly Vivarium has been closed during the project. It will take until November for removal of all the marble panels and another month for installation of the solar panels.
The problem with the marble slabs was discovered when Milwaukee County did inspections of the exteriors of many county buildings, following the O'Donnell Park fatality in 2010, Censky said. A 15-year-old boy was killed and two others were injured when a concrete slab fell from the O'Donnell facade, prompting a county-wide review.
The museum panels were not considered at risk of failing.
"It was a serious enough problem for us to want to remove the marble panels and reinstall them with new (metal) clips," said Greg High, director of Milwaukee County's architectural and engineering division.
The county owns the museum building at 800 W. Wells St.
The original idea was to replace only damaged panels with new ones and add new connectors for all 234 panels. But that proved too costly and would not have permitted the addition of insulation, High said.
After further study, the county initially decided to replace all the marble panels with ones made of a composite material that resembles stone and to add an insulation lining.
Museum officials wanted something that fit with the museum's sustainability ethic and agreed to cover the extra $172,000 cost of switching to solar panels, Censky said. A donation covered that portion.
The full cost of the project is $932,000, with $760,000 of it falling on taxpayers.
The panels, fabricated locally by Helios USA, will generate about 77,000 kilowatt hours of electricity a year. The energy cost savings are estimated at $300,000 over 30 years.
Because the panels are mounted on a vertical surface, they'll be most effective at capturing energy from the sun in winter, when the sun is lower in the sky and can strike the panels more directly, High said.
The shiny black panels, when installed, "will add dimension" to the W. Wells St. side of the museum building, a report by Censky to the county says.
"The contrasting look will signify that you have arrived at your destination," the report says.
A bronze whistling swan sculpture, removed from the museum's south wall to make way for the solar panels, will be reinstalled on a nearby west-facing wall, museum spokeswoman Carrie Trousil Becker said.
Replacing marble panels on the north side of the building with composite panels will cost about $841,000, plus $618,000 more for window replacement on that side. Those repairs have been recommended for 2014, but have not yet been approved.
Repairing the rest of the outer walls of the museum would cost about $900,000 and has been requested for 2015.