About a month ago, the title of largest operational U.S. photovoltaic plant belonged to the 55-megawatt (DC) Sempra Copper Mountain solar facility in Boulder City, Nev., about 40 miles southeast of Las Vegas, which boasted 775,000 First Solar (Nasdaq:FSLR) solar panels.

That is so last month.

The crown heralding the largest operational PV plant in North America now belongs to the 100 megawatts on-line of the 290-megawatt Agua Caliente solar project in Yuma County, Arizona. Construction is still in progress, with completion expected in 2014. Agua Caliente is owned by NRG Energy (NYSE:NRG). First Solar will build, operate and maintain the site. PG&E has a power purchase agreement in place for the electricity generated by the project. When completed, the project will hold the title of world's largest PV project until a few other behemoths go live.

Local officials and representatives of NRG, First Solar and MidAmerican Solar gathered yesterday to mark the project’s first 100 megawatts being delivered to the grid. According to a press release, the project’s construction phase is creating an average of 400 jobs, with over 80 percent of the workforce coming from Arizona.

The Agua Caliente plant will eventually deploy 400 units of SMA's Sunny Central inverters. The project will deploy fault ride-through and dynamic voltage regulation, technologies that are new to solar power plants in the United States.

The 290-megawatt Agua Caliente solar project has received a $967 million loan guarantee from the U.S. Department of Energy.

Here's a table of operational PV power plants in the U.S. courtesy of GTM Research. Meet the analysts who put together these data sets at our Solar Summit in Arizona next week.

Project Developer State Size (DC) PV Tech Owner Agua Caliente Phase 1,2 First Solar AZ 100 MW CdTe (FSLR) NRG MidAmerican Copper Mountain Sempra NV 55 MWdc CdTe (FSLR) Sempra Mesquite Solar One Sempra AZ 46 MWdc c-Si (STP) Sempra San Luis Valley Iberdrola CO 38 MWdc c-Si (SPWR) Iberdrola Long Island Solar Farm BP Solar NY 37 MWdc c-Si (BP) BP/MetLife Cimarron 1 First Solar NM 34.5 MWdc CdTe (FSLR) Southern Co Webberville Solar SunEdison TX 34 MWdc c-Si (Trina) Metlife/Longsol DeSoto Next Gen Solar NextEra FL 28 MWdc c-Si (SPWR) NextEra Stillwater Solar-Geothermal Enel Green NV 27.6 MWdc Enel Green Roadrunner Solar NRG Energy NM 25 MWdc CdTe (FSLR) NRG Energy

(Megawatt values are in DC and we assume an 87% DC-to-AC derate factor for projects that are quoted in AC. Data from GTM Research.)