For purposes of this section "cleaner fuels" means:
(1) biodiesel blends of 20 percent or greater by volume (B20-B100);
(2) compressed natural gas;
(3) ethanol blends of 70 percent or greater by volume (E70-E100);
(5) liquefied natural gas; and
(6) liquefied petroleum gas.
When purchasing fuel for use in the central motor pool or for use in a motor vehicle owned or leased by an agency, the commissioner or the agency shall purchase, and shall require persons purchasing on their behalf to purchase, cleaner fuels for use in the motor vehicle if cleaner fuels are reasonably available at similar costs to other fuels and if cleaner fuels are compatible with the use to which the motor vehicle is put.
When purchasing a motor vehicle for the central motor pool or for use by an agency, the commissioner or the agency shall purchase a motor vehicle that is capable of being powered by cleaner fuels, or a motor vehicle powered by electricity or by a combination of electricity and liquid fuel, if such a motor vehicle is reasonably available at similar costs to other vehicles and if the vehicle is capable of carrying out the purpose for which it is purchased.