An energy commentator says power generators - or gen-tailers - make more money when they're burning coal. That's created a perverse incentive which is blocking new renewable power projects. Last year, Aotearoa imported 1 million tonnes of low-grade, dirty-burning coal from Indonesia because there wasn't enough wind, rain or gas available. Māni Dunlop spoke to energy commentator and economist at Victoria University's Institute for Governance and Policy Studies Dr Geoff Bertram.