A well-connected Indonesian marine renewable energy company and OpenHydro, a unit of French state-owned naval defense company DCNS, aim to be the first to plug into the vast untapped tidal energy potential of the world's biggest archipelago.

Renewables have so far played little part in Indonesia's power sector, despite the country sitting on the world's biggest geothermal reserves and being bathed in sunshine, crowded out by an abundance of cheap coal and bureaucratic bottlenecks.

But declining costs of renewable electricity and a new push by President Joko Widodo to develop renewables in the remote eastern parts of the archipelago are changing the picture.