A trail-blazing utility that against full distributed energy.

One of Ignacio Galan’s early jobs as an engineer was to design lead-acid batteries for the milk floats that used to trundle around Britain’s streets.

So the 66-year-old Spaniard, who heads Iberdrola, one of the world’s largest utilities, claims he has been thinking about the storage of electricity for his whole career.

That is useful, because for the second time since he took over Iberdrola in 2001, the industry faces a fork in the road.

This time round, the big debate in energy is about batteries and storage.

The first time, Mr Galan blazed the right trail.

He made a prescient bet on renewable energy, turning Iberdrola into one of the world’s largest providers of onshore wind while at the same time underpinning returns with relatively safe, regulated electricity networks in America (Avangrid) and Britain (ScottishPower).

Some European peers, such as Germany’s E.ON and RWE, took the opposite approach, prioritising conventional fossil-fuel-fired power plants in less regulated markets.

In the past five years, the Germans have been through near-death experiences, and have belatedly created stand-alone renewables and grid businesses.

Iberdrola’s share price has more than doubled.

The renewables revolution has, in turn, caused the latest dilemma, because intermittent sun and wind require ways of storing electricity as a backup.