For those old enough to have seen the long-running television series "Dallas" ('78-'91), the scheming oil baron J.R. Ewing stands out as one of the more memorable characters.

Played by actor Larry Hagman, J.R. was the classic TV bad guy — who, according to Wikipedia, was "constantly plotting subterfuges to plunder his foes and their Texas-sized wallets". (Insert evil oil baron laugh here.)

In real life, however, Hagman is nothing like his character; preferring the clean blue of solar panels to the black gold desired by J.R. In fact, he owns the world’s largest residential array in Southern California — outputting some 94 kilowatts to take his 43-acre ranch completely off-grid. (The ranch was for sale last year for $11 million, but is now listed at $9.5 million.)

Which brings us to a new ad campaign featuring Hagman once again donning his J.R. costume and telling the world that his oil days are far behind.

“In the past, it was always about the oil,” Hagman says in a new TV commercial for German photovoltaic maker SolarWorld. “The oil was flowing and so was the money. Too dirty. I quit it years ago.”

The ad then shows Hagman throwing on a 10-gallon hat and stepping outside to look up at an array of solar panels on his roof. “But I’m still in the energy business,” he says. “There’s always a better alternative.”

“Shine, baby, shine,” he says, ending the commercial with his trademark J.R. laugh.

Hagman says the BP oil spill, coupled with Sarah Palin's "Drill, Baby, Drill" chants, inspired him to bring the J.R. character back and encourage the "Shine" tagline. “With all that oil gushing away in the Gulf, I figured it was time to call for a new direction in where we’re getting our energy,” the actor said in an interview earlier this week.

In return for Hagman's services, SolarWorld donated a massive amount of panels to the Solar Electric Light Fund, a nonprofit group that builds solar systems in poverty-stricken areas of the world. It's estimated that the group's most recent donation to earthquake-stricken Haiti will be enough to power five health clinics.

Check out this great interview with Hagman chatting about his love of solar energy.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

'Dallas' star returns in solar energy ad
Actor Larry Hagman takes his oil baron character in a greener direction.