A new Australian carbon offset company has been accused of potentially misleading customers by offering to generate thousands of credits for their solar panels and electric vehicles in a scheme that climate campaigners have labelled as junk.

Not-for-profit group Climate Integrity has written to the corporate watchdog asking for an investigation into Aetium, a company which is asking consumers and organisations to register their rooftop solar, EVs and forests in return for carbon credits.

One expert told Guardian Australia that Aetium’s online scheme had “jettisoned” a core principle in the world of carbon offsets – that projects can only generate credits if they would not have happened without the financial incentive.

More than 4,000 projects have been registered with Aetium since February last year, including more than 150 by the Cassowary Coast regional council in Queensland and more than 30 EVs owned by the Europcar rental car service, according to the scheme’s website.

The company defended its scheme and said it aimed to challenge the current system of how people and organisations could be rewarded for actions they had taken to cut emissions.

In its complaint to the Australian Competition and Consumer Commission, climate advocacy organisation Climate Integrity alleges Aetium is misleading consumers about the carbon offset scheme’s potential environmental benefits.

A key concern was the scheme allegedly failed the “additionality” standard – a safeguard in carbon offset schemes that tests whether emissions reductions would have occurred without the scheme.

This aims to ensure credits bought represent additional emissions reductions, rather than business-as-usual activities.

“Aetium’s credits fail to meet an additionality test because consumers signing up to the scheme would have bought and used their EVs or solar panels whether Aetium existed or not,” Climate Integrity’s executive director, Claire Snyder, said.

On its website, the company says that:“At Aetium, ‘additionality’ means the CO2 reduction would not have occurred if the solar system, EV or forestry did not exist”.

Snyder said Aetium’s definition was “out of step with virtually all established carbon credit schemes and the evidence-backed view of climate scientists”.

“Failing to satisfy the additionality test runs the risk that consumers become misled about their contributions to reducing emissions, and could ultimately undermine efforts to tackle the climate crisis,” she said.

‘Divergent’ from accepted practice

Aetium says it is not currently generating money from the scheme. According to its website, it would make money through registration fees it plans to begin charging from 1 March and by collecting a 7% share of the carbon credits it issues.

According to Aetium’s project registry, the Cassowary Coast regional council in far north Queensland has registered 131 forest projects and 23 solar PV installations, representing about 4,500 tonnes of CO2 credits, with the company.

It also shows more than 30 electric vehicles owned by the international rental car company Europcar are registered with Aetium.

Aetium’s managing director, Christopher Ride, said that, to date, “no carbon reductions have been certified by Aetium, no fees have been taken, no credits have been sold or retired, and no payments have been made” due to a minimum 12-month certification period for projects that the company has set.

He said the company had not been made aware of any formal complaint to the ACCC. The ACCC confirmed to Guardian Australia it had received a complaint.

_{Sign up: AU Breaking News email}

The international Integrity Council for the Voluntary Carbon Market’s set of principles says emissions reductions “shall be additional, i.e., they would not have occurred in the absence of the incentive created by carbon credit revenues”.

Prof Andrew Macintosh, an environmental law professor at the Australian National University and the former head of the federal government’s emissions reduction assurance committee, said: “Of all the registries I have reviewed globally, Aetium stands out as one of the most divergent from accepted practice.”

He said the cornerstone of this was the concept of additionality.

“Aetium have jettisoned this principle and instead try to redefine additionality, with the consequence that they will issue credits for standard activities where the emissions reductions have nothing to do with the incentive provided by the scheme,” he said.

“From the information available, there also don’t appear to be third-party verification processes and the scheme seems to fall incredibly short of standard practice regarding transparency.

“I feel badly for anybody who buys credits from Aetium in the belief they are helping ‘fight climate change’.”

In response to questions from Guardian Australia, Ride said: “We believe the current system should be challenged, and genuine change is needed.

“We need divergence from the accepted practices.”

He said the company wanted to reward broad participation in driving down emissions. Ride said that it remained “unknown” whether Aetium would could ultimately generate sales from the credits it issued but “our hope is this will encourage more awareness and more investment”.

Aetium also promotes its membership of the Smart Energy Council, Electric Vehicle Council and Carbon Market Institute and its status as a signatory to the Australian Carbon Industry Code of Conduct.

A Smart Energy Council spokesperson said membership was open to any organisation in the renewable energy sector, and an Electric Vehicle Council spokesperson said it was not a regulator and it was common for members to use its branding.

A Cassowary Coast council spokesperson said the council had registered its solar installations and bushland reserves with Aetium as a trial and any credits would be used to reinvest in “like-minded projects”.

Dr Sasha Courville, chief executive of the Carbon Market Institute, said membership of the institute “does not include independent checks of business activities” but Aetium was bound by the Australian Carbon Industry code of conduct.

But she said the code “does not regulate or assess the technical quality of carbon credits”.

She said the institute supported maturing standards in the voluntary carbon market and pointed to the “important work” of the Integrity Council for the Voluntary Carbon Market that “has developed a global benchmark for high-integrity carbon credits”.

The Guardian requested comment from Europcar.