Two decades ago, BP set out to transcend oil, adopting a sunburst logo to convey its plans to pour $8 billion over a decade into renewable technologies, even promising to power its gas stations with the sun. That transformation - marketed as “Beyond Petroleum” - led to manufacturing solar panels in Australia, Spain and the United States and erecting wind farms in the United States and the Netherlands. Today, BP might be more aptly branded “Back to Petroleum” after exiting or scaling back its renewable energy investments. Lower-cost Chinese components upended its solar panel business, which the firm shed in 2011. A year later, BP tried to sell its U.S. wind power business but couldn’t get a buyer.Even as governments and environmentalists forecast a peak in oil demand within a generation - and China and India say they may eventually ban gasoline and diesel vehicles - leaders of the world’s biggest oil firms are not buying the argument that their traditional business faces any imminent threat.