NAB chief executive Andrew Irvine labelled the nation's energy mix "sad" and said achieving net-zero emissions by 2050 was possible if renewables were harnessed.
"Australia should be an energy superpower," Mr Irvine told a parliamentary inquiry into the big four banks on Wednesday.
"We are blessed with incredible amounts of sunshine, wind resources, with some hydro capacity, and one of the world's largest reservoirs of natural gas.
"The fact that we are in a situation where we have a possible issue with a supply and demand imbalance on energy is sad and shouldn't have happened."
He said there was too much political debate around net zero and energy prices being compatible, and he strongly believed that was the "wrong narrative".
"As a country, we need to be doing a much better job of getting energy to market, both renewable and natural gas, to decarbonise the grid, get rid of the coal and become an energy superpower."
"We could have one of the world's lowest energy costs, deliver net-zero energy and be a wonderful exhibit to the world."
The nation has not focused on approving supply, which was costing every household, Mr Irvine said.
Earlier in the hearing, ANZ boss Nuno Matos suggested big banks should team up to offer joint branches in regional Australia, saying access to financial services was crucial.
The banking industry has agreed not to close any additional sites in regional Australia until at least mid-2027, and the ANZ boss said a plan was needed for the following years.
"Solutions like remote ATMs should be further explored. Solutions like banking hubs, which basically are multi-bank branches, should be explored," he told the inquiry.
Mr Irvine said there would be no mass branch closures while he was in charge of NAB, despite some regional branches having three customers an hour.
Mr Matos was also forced to defend his company's conduct after it was slapped with a record $240 million penalty for bungling a bond sale and ripping off customers
The corporate regulator says ANZ potentially cost the government $26 million by incorrectly reporting bond trading data while managing a major government deal, while also failing to respond to customer hardship notices and not refunding fees charged to dead customers.
Mr Matos said the failings were driven partly by a "good news culture" and a lack of self-awareness at the institution.
"The bank fell short of what is expected of us, and for that, I offer an unreserved apology," he said.
The company maintained the government lost nothing in the bond sale and said while ANZ breached some of its licensing obligations, it was not accused of market manipulation or over-hedging.
ANZ also announced in 2025 it was slashing its workforce by eight per cent across its institutional and retail divisions.
Mr Matos, who joined the bank in May, said cultural change was needed to prevent the misconduct happening again.
Parliament hauled in the big four bank leaders for the two-day committee hearing.
Commonwealth Bank chief executive Matt Comyn told the inquiry he supported the Reserve Bank's proposal to remove surcharges on eftpos, Mastercard and Visa cards, which would save consumers more than $1 billion a year.
But he urged the RBA not to be too hasty with the changes.
Mr Comyn said the plan would make payments in Australia substantially lower than anywhere else in the world, while favouring international companies.