Oil companies want to become power utilities to meet rising demand from electricity in transport and from growing populations. The strategy makes sense, but would also bring risks for regulators and consumers if it were to create a new breed of gigantic energy-controlling monopolies.

On one hand, watchdogs in developed markets such as the UK should welcome the introduction of relatively new players like Shell and BP to challenge the Big Six conventional utilities. On the other, electricity markets are politically sensitive and oil majors would make easy targets for politicians keen to be seen protecting consumers if profits are put too far ahead of the public good.