Well, it could also be nuclear powered.
Don't forget hydro. The northwest uses a lot of hydro, hell, even the desert southwest uses it - Hoover Dam.
They will claim it is solar or wind powered.
There used to be a lot of wind powered ships.
“Nuclear powered road vehicle” is not as far out as some may think.
By adapting the design of Thorium-fueled Molten Salt reactor by miniaturization, to where it still produces very significant heat, but is now small enough to be mounted on the chassis of a road vehicle. Heat energy is the medium by which the power of any fuel is harnessed, and a reciprocating internal combustion engine is only one of the mechanisms that may be used. A design of a reciprocating engine that uses only hot air as a medium, the Stirling engine, could use air heated by the Thorium power cell, and convert it to propulsive power. The one waste product of this operation is excess heat, as the reactor would be heating continuously.
There would be ways to utilize this continuous production of heat energy, by banking it in a huge water reservoir, as a heat bank. directing the excess heat into the water, and using this system for such purposes as home heating, or as any engineer knows, a number of industrial purposes.
There's about a 10% chance of that, whereas there's about a 60% chance it's coal fired. Plus, it yanks the envirolibs chain better that way.