Retail power faces reconsolidation challenge

The market share of challengers hits a landmark figure, but M&A could remake a hegemony, simply with different actors

The UK’s retail energy sector achieved an unenviable reputation for being a broken market over the last two decades. This was true for both electricity and gas, which were dominated by a so-called ‘Big Six’. At the start of the 2010s, these companies had a 100pc share of the residential power market, according to figures from regulator Ofgem. The Big Six was made up of UK utilities Centrica, born out of the old British Gas monopoly, and SSE, in addition to units of France’s EdF, Germany’s RWE and Eon and Spain’s Iberdrola. They were vertically integrated businesses and owned the vast majority of conventional UK generation assets, which was a significant barrier to entry. Their dominance beca