Bitcoin mining firm Iris Energy is said to be raising an extra US$200 million ahead of a direct listing on the Nasdaq (NASDAQ: NDAQ) which could value the sustainable business at $1.5 billion.

According to Bloomberg, the Sydney-based miner who has used renewable energy to power its infrastructure has been meeting with potential investors. The company is also reportedly looking to find an advisor.

Iris Energy, co-founded by Australian brothers Dan and Will Roberts, both ex-Macquarie staff, is a sustainable Bitcoin miner that owns and operates real assets, including data centre infrastructure.

The company has secured additional data centre development sites and new computing hardware which, with further funding, will expand capacity to 180MW (4.5EH/s) across multiple sites in 2022, making Iris Energy one of the largest Bitcoin miners in the world.

According to CEO Jason Conroy, ex-Transgrid CFO, the business’ roadmap is to have over 500MW of deployed computing capacity within the next three years.

Iris Energy’s currently operates a 9MW data centre in British Columbia, Canada, the company’s last operational update said.

Its expansion to 30MW (equivalent to 0.7EH/s) of computing capacity is on track to be completed in Q4 this year, which would be generating up to $90 million of annual gross profit to Iris Energy in the current market.

Iris Energy has signed binding documentation to acquire extra greenfield development sites in Canada along with new computer equipment orders which, with further funding rounds, are expected to add an additional 150MW (equivalent to a further 3.8EH/s) of total computing capacity in 2022.

Last May, the company closed on a $50 million equipment financing facility with “a respected North American institution”.

Iris Energy said the facility was going to be applied to the purchase of Bitcoin mining servers as part of the expansion of Iris Energy’s operations in Canada.

Conroy explained then: “This financing is another institutional endorsement of Iris Energy’s sustainable business model and enables us to continue to expand our operations following our recent capital raising of AUD$110 million, cornerstone by Australian institutional funds.”