Schering-Plough Corporation, the New Jersey-based pharmaceutical manufacturer, is about to make solar history, but not with the help of the state’s largest energy company.

Schering announced today that it will install the nation’s largest array of solar roof panels. The solar system will be built on eight rooftops on buildings throughout the company’s campus in Summit , NJ.

The company’s energy partner in the venture, however, is not Public Service Electric and Gas (PSEG), New Jersey’s largest energy company. PSEG has has been making headlines with a variety of recent clean-energy initiatives in New Jersey, from commercial and residential loans to customers interested in solar installations to a proposal for an off-shore wind farm and public ruminations over possibly building the state’s first new nuclear power plant in decades.

Schering-Plough instead has selected PPL, a Pennsylvania-based energy company, to design, construct and operate the 1.7-megawatt solar system.

When complete, the project will give PPL ownership or control over solar projects with a total installed capacity of about 10 megawatts.

In a news release today announcing the project, PPL says it “continues to explore partnership opportunities to develop additional solar energy projects in New Jersey and throughout the 13-state power market managed by PJM Interconnection.”

Am I imagining it, or does that quote not contain a hint of interstate, competitive glee?