The Murchison Hydrogen Renewables project, under development near the Western Australian coastal town of Kalbarri, will use 5.2 GW of wind and solar to produce renewable hydrogen. That will then be converted to an estimated 2 million tons of green ammonia per annum, for domestic use and export.

The ambitious project was first proposed by Hydrogen Renewables Australia in 2019. The project is now being led by investment firm Copenhagen Infrastructure Partners via its Murchison Hydrogen Renewables (MHR) offshoot. While no specific details about the ambitious project were previously available, a referral filed this week with the state’s Environment Protection Authority (EPA) reveals the true scale of the project.

The submission shows that MHR plans to install about 1.5 GW of solar PV and an estimated 700 onshore wind turbines with a combined capacity of about 3.7 GW. A Power-to-X (PtX) plant will be constructed on site to convert the renewable energy into green hydrogen, which will be converted into an estimated 2 million tons of green ammonia per year.

The facility will be equipped with about 3 GW of electrolyzers while a purpose-built water treatment and desalination plant will generate about 6 giga-liters of “demineralised water” a year for use in the production process. The PtX plant will be coupled with 250 MW to 350 MW of battery storage with a two-hour duration that will be used to regulate the renewable energy prior to distribution to the electrolysers.

The proposal also includes hydrogen storage which will be used as an intermediary between electricity and ammonia. It is anticipated that up to 200 hydrogen storage vessels, each with a capacity of up to 680 tons, will be installed.

The green ammonia produced at the site is to be exported to emerging green energy markets with a pipeline to link the PtX plant and storage facility to a marine export facility. The submission also highlights the potential for local, domestic offtake as hydrogen or ammonia.

Hydrogen Renewables Australia has already secured a long-term agreement with the pastoral lessees of the Murchison House Station and announced Siemens as the proposed plant’s technology partner.

The project is expected to be developed in three stages. The first stage would comprise a demonstration phase producing hydrogen for transport fuels, to be followed by an expansion to blend with natural gas into the nearby Dampier to Bunbury pipeline. The third and final phase would include an expansion to produce hydrogen for export to Asian markets.

Hydrogen Renewables Australia has previously indicated the potential for the proposed project to scale up over a six-year period, reaching full capacity toward the end of this decade. The referral to the EPA is currently open to public comment until May 8.