The Turnbull government's preferred energy plan uses modelling in line with an Emissions Intensity Scheme that it rejected while significant doubts remain over the application of its reliability rules, two factors that may stymie its acceptance by right-wing Coalition MPs and the states supposed to implement it.

In a neat twist, Josh Frydenberg, the federal Environment and Energy Minister, will return to Hobart on Thursday to meet state and territory counterparts almost a year since he stood on the city's waterfront to rule out an EIS after a backbench revolt.

Hard to swallow: Prime Minister Malcolm Turnbull with Josh Frydenberg, the Environment and Energy minister. Credit:Andrew Meares

This time around, the plan is called a National Energy Guarantee (NEG) that, as Fairfax Media has reported, promises to save $120 a year for average households from 2020.

To be sure, the Australian Energy Markets Commission, which oversaw the NEG, says the scheme is not a dreaded EIS because there is no specific trading mechanism "of any kind".