When a headhunter contacted Andrew Sunderman in 2012, asking whether he wanted to become the chief financial officer (CFO) of Houston-based Direct Energy, the industry veteran saw it as an intriguing new challenge. Over the past three decades, he had worked for oil producers, pipeline operators, power firms and banks – but never an electricity retailer such as Direct Energy, a unit of UK utility Centrica that serves nearly 5 million customers across North America.

"It was a very interesting job