However, the CEOs generally agreed the current weak electricity demand growth and a surplus of generation capacity would make higher margins difficult to achieve in the short to medium term.
"It's going to be a long hard slog," said Barnes.
Meridian Energy Mark Binns expressed concerns about whether the stress testing regime being proposed by the Electricity Authority would create the degree of security it was intended to achieve.
Energy Minister Phil Heatley opened the conference by acknowledging the extent of New Zealanders' concern that more oil and gas exploration threatens the country's environmental integrity.
"New Zealanders are very engaged in how we get economic advantage with the environmental rules and regulations that are put in place."
He declined to be drawn on whether the government would adopt a recommendation of the Green Growth Advisory Group for a Norwegian-style sovereign wealth fund, which would collect royalties from oil and gas development for investment in public infrastructure.
"Whether we create such a fund to make that (economic benefit from oil and gas) more 'line of sight' is something we are obviously considering," Heatley said.
He was critical of gas industry players' slowness in providing information required to fully understand last year's Maui gas pipeline outage.
"I'm disappointed the companies haven't surfaced with all the information and I have asked why that is."