A plan to "bottle" sunlight via hydrogen in Western Australia's Pilbara and export it to Japan is edging closer to reality, according to a Sydney-based company.

Renewable Hydrogen is planning to establish a small 10-megawatt-hour PV solar farm near Karratha.

As part of the pilot program, the company is proposing to purify seawater before separating hydrogen from oxygen via electrolysis, a process powered by solar energy.

The hydrogen becomes a vehicle for storing renewable energy and is converted into transportable forms for export.

Renewable Hydrogen's initial plan is to export the hydrogen to Japan as ammonia, but executive director Andrew Want said the hydrogen could also be converted into other forms such as synthetic methane or LNG.

"We will effectively bottle it and ship it to Japan on a true industrial scale," Mr Want said.

The company, along with the Pilbara Development Commission and a confidential Japanese partner, is finalising a feasibility study into the pilot project.

Speaking on the phone from Japan where he was meeting with business partners, Mr Want said the Pilbara was the ideal location for the ambitious plan because of its economies of scale.

The region receives abundant sunlight, generating an average of 24 megajoules per square metre a day of solar radiation, according to the Bureau of Meteorology.

There is also plenty of land suitable for solar farming, a small population mostly based in six main centres and significant LNG and export infrastructure.

Targeting Japan's 'hydrogen society'

Creating and exporting hydrogen under the planned method remains an expensive process, but the company is hoping to tap into the Japanese Government's new appetite for renewable energy sources and eagerness to shift away from nuclear power after the 2011 Fukushima disaster.

Prime Minister Shinzo Abe has championed a "hydrogen society" and supported the investment of billions of yen in hydrogen projects, including cars powered by the emission-free fuel.

"Targeting the emerging hydrogen economy in Japan, the pilot plant has the potential to lead to commercial-scale investments and has been identified as a further opportunity for transformational reform in the region's economy through the export of renewable energy resources," the Pilbara Development Commission wrote in a recent regional investment report.

The company estimates that a 1 gigawatt PV solar farm could generate about 2 million megawatt hours of electricity. This is capable of creating about 40,000 tonnes of hydrogen which could be used to make 200,000 tonnes of ammonia.