One of the country’s top energy bosses says Australians will pay more to decarbonise the energy grid via higher taxes or rising power bills, and warns subsidised rooftop solar is hurting the viability of large-scale renewable generation.

Declaring himself to be 100 per cent in support of renewable power, Alinta Energy chief executive Jeff Dimery said the key question facing the nation was no longer whether climate change was happening, but how best to decarbonise the grid.