There are no plans to introduce all-electric buses to the island.
Public transport bosses insist that there are no zero emissions vehicles currently available that have the power and range required.
Bus Vannin has a rolling £25.2m programme of bus replacement, with £1.4m earmarked for new vehicles in this year’s Budget.
But all purchased so far are diesels - although six single deck ’hybrid’ vehicles are due to be delivered this year.
These hybrids combine a conventional internal combustion engine with an electric propulsion system.
The Manx government has pledged to ban the sale of new petrol and diesel cars by 2040 as part of its target to become net-zero in carbon emissions by 2050.
Some towns in the UK are already using all-electric buses on some routes.
In Guildford, for example, the Glide park & ride route has been operating with a fleet of zero-emission single deckers since January last year.
The fleet of Enviro200EVs are built by Alexander Dennis, which is based in Surrey’s county town.
Bus Vannin said the diesel version of this bus has been trialled on-island, but was deemed ’inappropriate’ for use here.
’The electric version does not have the range required for services on the island,’ a spokesman for the Department of Infrastructure said.
He added: ’The Isle of Man government currently has no plans to buy all-electric buses, but only because the duty cycle available is insufficient for the island’s needs due to the nature of services here being mainly inter-urban, at higher speeds.
’This means that buses that can operate short services in big cities simply won’t have the power or the range for our requirements.’
He said following successful trials last year, an order has been placed for six hybrid buses which are due to arrive this summer.
Bus Vannin has a fleet of 52 Mercedes buses comprising 33 Citaro single deckers.
There is an electric Citaro but Bus Vannin said the current version will not operate to the required duty cycles in the Isle of Man.
The DoI spokesman said: ’Mercedes has advised us that it expects to upgrade the model in 2022 or 2023 and that this revised bus is likely to be more suitable for our need.
’The department has already requested an early trial of a prototype of this bus before production starts.’
Bus Vannin says its rolling bus replacement programme has cut maintenance costs. Its fleet has been cut from 90 to 68. It says there are minimum orders with some manufacturers which means it tends to order six buses a year.
But it denies that it has a contract with Mercedes that obliges it to buy a certain number of buses a year.