Deep in a tangle of planning bureaucracies in western Beijing, the future of a country nearly 3,000km away is under discussion. Xie Qiuye, president of China’s Electric Power Planning & Engineering Institute, has been charged with developing an electricity plan for Laos, a nation struggling with a glut of electricity supply from Chinese-built dams on the Mekong river.

Mr Xie’s job is to find a rational solution for Laos, even as powerful Chinese construction companies vie for more dam contracts in China’s poor southern neighbour. His answer — to make Laos into a regional power hub, exporting electricity to the rest of south-east Asia — depends on a technology that is being pushed hard by a powerful former state electricity boss with a vision for connecting world power markets.

In Laos, in Brazil, in central Africa and most of all in China itself, ultra high-voltage cable technology that allows power to be commercially transported over vast distances with lower costs and increased load is justifying the construction of massive power projects. It is dubbed the “intercontinental ballistic missile” of the power industry by Liu Zhenya, its biggest backer and for a decade the president of State Grid, China’s powerful transmission utility.