Hydrogen suitable for taxis, buses and heavy goods vehicles: Study

Hydrogen is not cost-effective for cars in Singapore, but the clean fuel may be suitable for taxis, buses and heavy goods vehicles, according to a recent study to assess the feasibility of importing hydrogen for downstream uses.

American engineering firm KBR, in the study commissioned by the Government, said that because of the low mileage private cars chalk up in Singapore, hydrogen fuel cell electric vehicles (FCEVs) hold no clear advantage over battery-electric vehicles (BEVs).

It pointed out that the cost of hydrogen would have to be negative US$7.40/kg in 2050 for an FCEV to compete with a BEV.

"It is recommended that Singapore focus its private car transition on BEVs and associated infrastructure," added the study, which was released in June.

The same goes for light goods vehicles, which clock relatively short distances.

The analysis is slightly different for taxis, which "travel the greatest average distance of all vehicle categories in Singapore, and hence are subject to more recharging/refilling time considerations".

Because of the long downtime for charging, BEV taxi operators might have to increase their fleet size by 8 per cent to maintain availability and driver revenue.

Buses and heavy goods vehicles are better suited for conversion to FCEVs, the study noted. This is because BEV versions require inordinately large batteries and long charging times.

The average daily mileage of a public bus in Singapore ranges between 95km and 320km.

With a 50kg hydrogen tank, an FCEV bus will have an approximate range of 400km and a refilling time of a few minutes, while a BEV bus fitted with a 350 kilowatt-hour battery will travel 250km and require in excess of 11/2 hours to charge using a 250 kilowatt charger.

The break-even price of hydrogen needs to be US$2.39/kg by 2050 for a hydrogen bus to compete with its BEV equivalent.

In 2019, the fuel was around US$16.50/kg in California.

"It is recommended that bus fleet operators maintain a careful view on BEV battery and charger developments and trends for heavy vehicles, and carefully examine the number of chargers required to maintain the existing night-time recharging model," KBR added.

As for heavy goods vehicles, cost parity between FCEVs and BEVs is expected around mid-2040.

The study noted that the heavy goods vehicle segment is "the only one where FCEVs are projected to be more economically viable than its BEV counterparts by 2050".

KBR pointed out, however, that hydrogen refuelling infrastructure takes up more space.

The average space for a petrol station in Singapore is around 2,000 sq m, with the 186 stations occupying around 380,000 sq m.

An equivalent hydrogen dispensing network will require 1.6 million sq m of land - quadrupling the land take. This has partly to do with safety considerations.

A version of this article appeared in the print edition of The Straits Times on September 08, 2021, with the headline 'Hydrogen suitable for taxis, buses and heavy goods vehicles: Study'. Subscribe