The federal government's $5 billion Northern Australia Infrastructure Facility is considering funding toll roads and energy projects in the Far North, but it is remaining coy about whether it will help bank roll a new coal-fired power station.

The NAIF – which is set to announce its first funding by September – has whittled 124 expressions of interest to five projects which are under due diligence, including a rail link to Indian company Adani's $16.5 billion Carmichael coal mine in Central Queensland and Genex Power's $823 million Kidston pumped hydro and solar project in North Queensland.