There is no distinction made for driver age due to the type (electric, diesel, gas) of rider-operated lift truck.
Individual companies (or there insurance providers!) can set their own minimum age requirements for FLT operators (within the constraints of employment age legislation) except for those on dock premises which MUST be 18 or over.
The HSE Approved Code of Practice and Guidance Rider-operated lift trucks: Operator training states that young people under 18 years should not be allowed to operate lift trucks without adequate supervision unless they have the necessary competence and maturity, as well as having successfully completed appropriate training. Children under the Mandatory School Leaving Age should never operate lift trucks.