Environment minister Tse Chin-wan said on Friday that taxi owners can borrow up to HK$350,000 under a government-backed loan scheme to switch to electric vehicles.

The owners will be able to repay the money over 10 years.

Tse told an RTHK radio programme that if all taxi owners applied for the money, it would involve a loan guarantee of about HK$6.4 billion.

He said the authorities are also providing subsidies of up to half the price of an electric taxi in a trial scheme under the New Energy Transport Fund.

"If the [electric] taxi costs more than traditional ones, we'll subsidise the amount of the price difference. If it doesn't cost more, the subsidy we provide can cover half the price of the vehicle," he said.

"Of course, when the trade has found a suitable model [of electric taxi] after trial and [the electric taxis] are in use extensively, we will discuss the amount of subsidy with the sector."

The secretary for environment and ecology said 10 fast charging points suitable for electric taxis will be built this year, adding that the government plans to build a few hundred more across the territory.

Separately, Tse said the authorities aim to test double-decker buses that run on hydrogen fuel cells this year.

"We have to test the refuelling of hydrogen. So now we've decided to build hydrogen stations at a few locations, including Au Tau and Tai Po... Another one may be in Chai Wan," he said.

"And by doing trials we will see what safety standards are required, because we haven't had hydrogen-powered cars in Hong Kong before."

He added that rubbish trucks and container vehicles may also be included in the trial.