Constellation Energy (NYSE: CEG) just announced that it will develop a 5.38-megawatt solar installation for Toys “R” Us at the toy retailer’s nearly 1.3 million-square-foot distribution center in Flanders, N.J. (Constellation is in the midst of a mega-merger with Exelon to form a $52 billion utility behemoth.)

Constellation Energy expects to build, own and maintain the system, and Toys “R” Us will purchase all of the electricity generated from the solar panels under a 20-year PPA (power purchase agreement). The system is scheduled to be operable by summer 2011 and will be one of the biggest solar roofs in the world.

I spoke with Michael Smith, senior VP of green initiatives for Constellation Energy’s retail business. He leads the renewable business at Constellation, which does everything from solar power to RECs to helping customers meet their sustainability plans to offtakes from wind projects.  
 
The system will use more than 37,000 Uni-Solar PV panels on the standing-seam roof and expects to generate 72 percent of the electrical needs for the Toys “R” Us facility. 

The advantage to the Uni-Solar panels is that they are lightweight and relatively easy to install. Certain rooftops are weight-conscious and favor the lighter-weight flexible panels.

The problem with using Uni-Solar as a solar panel vendor is that the amorphous silicon (a-Si) technology used by the firm produces panels with relatively low efficiencies when compared to other solar panels manufactured in crystalline silicon (c-Si) or other thin films like cadmium telluride or CIGS. Additionally, Uni-Solar has a history of rocky financials and their most recent quarter revealed large losses and layoffs of 20 percent of their work force.
 
The Toys "R" Us installation is Constellation Energy’s sixth project in New Jersey, where state incentives and SRECs are driving strong growth in solar. Earlier this month, Constellation announced the acquisition of a 30-megawatt solar project in Sacramento, Calif -- a ground-mounted SMUD project. 

Constellation has approximately 95 megawatts of solar installations, completed or under construction, on about 30 projects in the U.S.  Smith said, "The site dictates the design." They are "technology agnostic" and can combine thin film with c-Si on rooftops, ground mount, or on parking canopies.

According to Smith, "Constellation is bullish on solar."
 
Constellation owns a fleet of generating units totaling approximately 12,000 megawatts of generating capacity and had revenues of $14.3 billion in 2010.