The Newcastle Herald believes this came about after Mr Broad told Mr Bowen that the Labor Party's pre-election promise of converting the Kurri Kurri gas turbine to 30 per cent hydrogen was impractical if not impossible, and that Herald articles reporting that this week may even have contributed to the situation.

Mr Broad was appointed to run Snowy Hydro in 2013, when the previous Labor administration was in power.

He retained the confidence of the Coalition throughout the Snowy 2.0 debate, then shepherded the organisation through the often vicious debate over the merits - or otherwise - of the Kurri plant. With "green" hydrogen as the new government's objective, he set the experts to work to find a way to make it happen.

Their reports, pointing out the problems - and the time and money needed to overcome them - have not gone down well in Canberra.

But if the information Mr Broad has put before his minister is correct, then his resignation and the appointment of a new CEO at Snowy Hydro will not change the eventual outcome as far as hydrogen is concerned.

In opposition, Mr Bowen was a prominent critic of the Kurri plant.

He may well have carried out a promise to "tear up the contract" had his predecessor, Angus Taylor, not ordered the turbines before the election.

Instead, in February, Labor rebranded Kurri as a "green hydrogen" project, before - it would seem - any serious work had been done in terms of feasibility.

With that work now casting doubt on the practicality of the promise, Mr Broad has suddenly found his position - with its reported $2.2 million salary - untenable.

Some will cheer a demise of the Kurri plant.

Many in the environmental movement believed it should never have been approved in the first place.

As unpleasant as the circumstances may be, Mr Broad's resignation may well trigger a new debate that looks more closely at the practicalities - or otherwise - of hydrogen.

But whatever has happened behind the scenes, the public deserves an honest explanation.