I don't believe Vicroads is correct. Please refer them to the legislation linked here:-
http://www.austlii.edu.au/au/legis/vic/consol_reg/rsr2009309/s102.html
(3) If a motor vehicle is a hybrid vehicle or an electric powered passenger car, the fee to be paid for registration or renewal of registration of the vehicle is— (a) nil, if the fee that would otherwise be payable under section 9 of the Act or Schedule 3 is less than $100; or
(b) in any other case, the fee that would otherwise be payable under section 9 of the Act or Schedule 3, less $100.
http://www.austlii.edu.au/au/legis/vic/consol_reg/rsr2009309/s102.html
(3) If a motor vehicle is a hybrid vehicle or an electric powered passenger car, the fee to be paid for registration or renewal of registration of the vehicle is— (a) nil, if the fee that would otherwise be payable under section 9 of the Act or Schedule 3 is less than $100; or
(b) in any other case, the fee that would otherwise be payable under section 9 of the Act or Schedule 3, less $100.