Malinauskas signed the agreement on the first leg of his United States trip, with California’s acting governor Eleni Kounalakis present.

The agreement includes a focus on developing clean renewable hydrogen projects, with collaboration between Hydrogen Power SA, the California Natural Resources Agency and California Energy Commission.

Other aspects of the deal include an agreement to exchange best practices in regulating the clean renewable hydrogen industry, advancing large-scale renewable energy generation and storage, supporting decarbonisation, exchanging best practices to support zero emission vehicle uptake, and strengthening critical minerals supply chains.

Malinauskas said the agreement was a “significant step forward” for the two states.

“We are both already leaders in our respective nations when it comes to renewable energy,” he said.

“It just makes sense that two global leaders in renewable energy…should work together to advance our shared interests in clean energy to advance our states’ economies and the world’s drive towards decarbonisation.”

California has been chosen as a National Hydrogen Hub by the United States Department of Energy, with a $1.2 billion investment to accelerating the state’s development of clean renewable hydrogen.

California’s lieutenant governor Kounalakis said the collaboration was “another pivotal step towards a sustainable, clean energy future”.

“Together, we acknowledge that the fight against climate change knows no borders,” Kounalakis said.

California Air Resources board chair Liane Randolph said “climate action requires collaboration and the sharing of successes and ideas, which is why the partnerships between South Australia and California is an important step”.

California’s nominal GDP of US $3.9 trillion makes it the fifth largest economy in the world, compared with Australia’s national GDP of US $1.7 trillion.