It contains no carbon in its molecular structure, and only produces water vapour when burned, which helps cut air pollution.

Tse Chin-wan, the secretary for environment and ecology, said on Monday that the development of hydrogen power, with enough infrastructure and talent training, would help the city reach its goal of carbon neutrality by 2050.

Beijing published a white paper in 2020 to promote the development of a hydrogen energy industry and related technology and increase the proportion of hydrogen in the nation’s fuel mix.

“Our country has stated clearly that hydrogen would be an important component of the national energy system in the future,” Tse said.

“Seizing the opportunities brought about by the development of hydrogen energy can help Hong Kong strive towards carbon neutrality, develop a new quality productive force and maintain international competitiveness.”

2. What type of hydrogen will be used in the trials?

Because of the high reactivity of its atoms, pure hydrogen does not exist in nature, but is found in compounds such as water and methane.

Hydrogen can be obtained by reforming hydrocarbon fuels or by methods such as thermal cracking, hydrolysis and water electrolysis.

So, even though hydrogen does not contain carbon, its raw materials or conversion processes still emit carbon, which offsets its decarbonisation benefits.

There are three ways of obtaining hydrogen at present, using grey, blue and green technologies.

Grey and blue hydrogen are produced through fossil fuels, but blue hydrogen has a smaller carbon footprint as it uses technology to capture carbon dioxide emitted during production.

Green hydrogen comes from renewable energy sources, such as wind power and solar photovoltaics, to electrolyse water into oxygen and hydrogen, but it can be up to four times more expensive to produce than grey hydrogen.

Tse said the government had retained “a certain degree of flexibility” when it formulated the strategy because of the “great uncertainty about the price competitiveness of green hydrogen”.

“This will prevent us from compromising on economic benefits when we are going too fast,” he explained.

3. What is the goal of the strategy?

Authorities hope Hong Kong can become a showcase for the nation in hydrogen development.

A city certification scheme for hydrogen energy, in line with the international standards, is expected to be ready by 2027.

The government will set up the city’s first public hydrogen refuelling station and start a trial on three hydrogen-powered street washers later this year.

Discussions on technical exchanges and experience-sharing with counterparts in mainland China will also start this year and a publicity campaign will be launched to boost knowledge of hydrogen energy.

Proposals for legislative amendments to provide a legal basis for the regulation of the production, storage, transport, supply and use of hydrogen as a fuel will be submitted in the first half of 2025.

Hydrogen gas is at present still regarded as a potential danger rather than an energy source.

Authorities expect to have infrastructure for hydrogen refuelling in Hong Kong, Kowloon and the New Territories by the end of 2027 and to have started collaboration with the mainland on a hydrogen supply network to the rest of the Greater Bay Area.

The Greater Bay Area is Beijing’s plan to turn Hong Kong, Macau and nine mainland Chinese cities into an economic powerhouse.

4. What sort of Hong Kong public transport will use hydrogen?

The city’s first hydrogen-powered double-decker bus, operated by Citybus, was put into passenger service in February and the company said it planned to add five more by as early as next year.

But its larger counterpart, KMB, has ruled out the introduction of hydrogen-fuelled buses.

Railway giant the MTR Corporation is expected to test a hydrogen-powered light rail train this year.

The government also wants to incorporate codes of practice for hydrogen-fuelled vehicles, maintenance workshops and hydrogen refuelling stations into the city’s legal framework.

5. What other hydrogen projects are likely?

A government working group had approved 14 hydrogen trial use projects by March.

These include Citybus’s plan to build a fuelling station at its depot in Sham Shui Po and a hydrogen production centre run by Towngas.

Other projects expected to start later in the year include a plan by petrochemical giant Sinopec to build a fuelling station in Yuen Long.

Other companies will also examine the feasibility of projects that involve cross-border hydrogen delivery and the use of hydrogen-powered generators at construction sites in remote areas.

Authorities will also explore using hydrogen-powered mobile machinery at the airport, port facilities, container terminals and large-scale construction sites.

6. What are policies on hydrogen in other places?

The United States Department of Energy issued the National Hydrogen Energy Roadmap as early as 2002 to promote hydrogen energy from theoretical research to practical applications.

It also launched an action plan in 2004 and later invested in hydrogen energy and fuel cell projects to explore commercial applications of the fuel.

Washington clarified the strategic status of hydrogen energy in 2022 and set out short-, medium- and long-term goals and a timetable from 2022 to 2035.

The European Commission released plans in 2020 to spend hundreds of billions of euros over 10 years on an industrial chain spanning hydrogen production, storage, transport and refuelling.

Beijing released its first national top-level planning document in 2020 to clarify hydrogen’s strategic position in the nation’s energy and economic development.

It also announced medium- and long-term plans to boost the industry.

Six central ministries and commissions last August released guidelines drawn up to cover the industrial chain of hydrogen production, storage, transport and use.

President Xi Jinping has since May last year visited at least three provinces and cities, including Sichuan, Jiangxi and Chongqing, to push for the development of the industry.

Xi stressed the importance of increasing security in key areas such as energy and speeding up the construction of new energy systems in a speech in Chongqing in April.

Singapore announced plans earlier this year to use hydrogen as a fuel from 2035 as part of its drive to hit net zero carbon emission targets by 2050.

The city state has ruled that all new and refitted power plants must be at least 30 per cent hydrogen-compatible.

The power stations must also be able to be retrofitted to run entirely on hydrogen in the future.