CHONGQING - As the city promotes new energy transformation, Chongqing now rises the curtain of the hydrogen era, with hydrogen-fueled buses being operated to transport tourists and commuters between urban districts and suburbs.

Starting in October, Line 974 offers a route for tourism and business, operating between Mingyue Lake and Jintong Road, stopping at attractions like Liangjiang International Movie City and the critical research hub of Chongqing, Liangjiang Collaborative Innovation Zone.

They run like battery electric buses -- silent and fast. While compared to petrol buses, hydrogen buses, converting hydrogen energy into electricity, emit only vapor. In contrast with battery electric buses, they only take 15 to 20 minutes to complete a "full charge."

With 400km on each charge, the hydrogen bus almost exceeds in most aspects compared to the petrol and battery electric buses, except for one thing, which is the cost.

A full charge of a hydrogen bus indicates the process of hydrogen gas added to the gas cylinder. (Photo provided by Chongqing Liangjiang New Area Investment Invitation Group)

The current challenge to a massive promotion is the operation cost. Dai Xin, Deputy Director of Chongqing Liangjiang New Area Investment Invitation Group, who managed the introduction of hydrogen power companies, said that the price for hydrogen vehicles now is roughly one yuan per kilometer.

The high cost of hydrogen power comes from the high-cost production and storage because the gas form of hydrogen is highly flammable that needs to be handled sophisticatedly.

"Though it's not the cheapest way of running bus service, developing hydrogen buses has an advantage in our country. China produces about 33 million tons of hydrogen gas a year. If we use them properly, it would help the country to achieve the 'double carbon' goal," Dai said.

Before the hydrogen buses, Chongqing's truck producer SAIC Hongyan produced hydrogen trucks, becoming the national hydrogen energy pilot truck. Alongside the accelerating construction of hydrogen infrastructure, Chongqing plans to build 30 hydrogen refueling stations that can serve about 1,500 hydrogen vehicles.

The zero-emission might be the largest attraction to the country's urban administrators and people who work in the environmental field. China has become the largest hydrogen gas-producing country in the world. Developing hydrogen power is in its 14th Five-Year Plan, in accordance with the country's grand ambition to achieve the Carbon Peak by 2030 and Carbon Neutrality by 2060.