Guardian: BP’s green energy arm is under pressure from plunging oil prices and the credit crunch, its chief executive admitted yesterday. Vivienne Cox, chief executive of BP Alternative Energy, said it would be “foolish” to deny it was harder to get cash for projects in the current climate. “Like everyone else, we are looking at our total capital budget and we will tell you in February how we are placed,” she said. “It would be foolish to say there are no limits on capital …