I like the idea of the vehicle mods you've made, this one especially. However, I notice the mention of them using fuel in their descriptions. I was wondering if electric versions of these vehicles exist, or could be added at some point (preferably with an equipment grid large enough for solar panels/batteries). I want to download these, but I am currently trying to minimize my need for burnable fuels like coal, wood, and solid fuel.

Edit: I have done a bit of testing, and it seems the Warden (and I'll assume the other vehicles in your mods) are not capable of being fueled via electricity. If you do decide adding this functionality, I think adding compatibility with the Electric Vehicles Reborn mod might work nicely. It already adds the items necessary to create electrically powered vehicles.

There are 3rd party mods that add equipment grids to the vehicles which can give them power. I don't think they're updated yet.

Are there any you can name? I didn't think about third party mods, and I'd like to keep an eye on them if you know any. Thanks for the reply, by the way.

The mod I use now for that is Electric Vehicles Reborn. It has a library mod, and it is possible for other mods to add electric vehicles if I read it correctly. The only thing preventing the Warden from using electricity as its fuel is that it won't accept Electric Vehicles Reborn's transformer into its equipment slot (the transformer converts energy into vehicle-usable fuel). I hate to be troublesome, but if you could make the Warden's grid accept the transformer if Electric Vehicles Reborn is installed, that should take care of it.

If you are interested, here is the quote from the library's description:
"Support library containing all the logic required by Electric Vehicles to do its job. Useful for mods who want to make use of the functionality but are not interested in all the baggage prototypes that comes with Electric Vehicles. To do that simply register your own item and equipment prototypes using the remote interface which is described in remote.lua. See the electric-vehicles mod for a more involved usage example.

All the library does is recognize a special item called a transformer inside a vehicle's equipment grid, and consume its energy to fill the vehicle's energy buffer, allowing it to drive using electricity generated or stored in the equipment grid.
Please use GitHub to report issues and suggestions."