Partway during Friday's summit of the nation's energy ministers, Victoria's Lily D'Ambrosio interrupted a presentation by the Energy Security Board to query a dot-point about concessions for low-income earners.

"Where did that come from?" she reportedly asked, wondering who had directed that research. Such a proposal at this point was a "non starter".

The problem, though, is not so much the board's unsolicited research but the torrent of studies that comes out of the Melbourne gathering – and the fault lines that they may open up.

That work – presumably to be done well before the ministers meet for a "final determination" on the National Energy Guarantee (NEG) on August 10 in Sydney – includes more details on emissions targets, offsets, the reliability standard to accompany the emissions one, market power mitigation, and the thorny issue of "additionality".

Federal environment and energy minister Josh Frydenberg stepped up the charm offensive in the past two days, starting with an amicable dinner with his state and territory counterparts on Thursday, then a four-hour working session on Friday, becoming "much less Bolshie than earlier in the week", as one participant noted.