Transit Systems, which operates Australia's largest network of electric buses, revealed the figures on Thursday along with an estimate that the technology had saved the equivalent of more than 41,000 barrels of oil so far.
The figures come after most states and territories committed to swapping traditional buses for electric models before 2040, with some cities making the switch as early as 2025.
Transit Systems fleet general manager Mark Peters said the company's 58 electric buses in Sydney had already made an environmental impact and covered more than 1.5 million kilometres.
"We have come a long way since the initial trial," he said.
"We saved over 1.8 million kilograms of C02 tailpipe emissions in the three years since we launched the first (battery-electric bus) trial in 2019. That's equivalent to saving the energy of nearly 6000 cars."
Despite initial concerns about their range, Mr Peters said electric buses regularly returned to the depot with a "40 to 50 per cent" charge left in their batteries, and could be recharged in less than three hours.
Passengers were not always warned they were boarding an electric bus, he said, but feedback had been positive.
"Once they board, passengers become very aware that they are on an electric bus," Mr Peters said.
"They are much quieter, cleaner, smoother and generally more comfortable than diesel buses.
"If they've had a busy stressful day at work, they said they found it pleasant to be sitting on a more comfortable ride."
The Electric Vehicle Council said Australians could expect "year-on-year" growth for electric buses in Australia, with 18 models already operating in the country.
Six out of eight states and territories have set targets for a transition to zero-emission buses, with southeast Queensland and Perth expected to make the switch by 2025, and Tasmania and the rest of Queensland and Western Australia to join them by 2030.
Victoria has committed to buying only zero-emission buses from 2025, and NSW has set a deadline of 2035 in Sydney, 2040 for outer metro areas and 2047 for regional NSW.
The ACT has named 2040 for the switch, while South Australia and the Northern Territory have yet to set a date.
The Australia Institute's Climate of the Nation report, released on Thursday, showed 74 per cent of Australians supported state governments buying or leasing only electric buses from 2025, and 77 per cent supported the switch to zero-emission school buses.
Mr Peters said commuters could also expect to see hydrogen fuel cell buses on Australian roads in future as they had a longer range and required less infrastructure, making them suited to regional areas.
"We believe there is a place for both technologies in our metropolitan public transport deployments," he said.
