Here we have the sun, which is a much greener energy, and is now being used to power more and more small appliances, however if you wanted to drive a car by solar power you would need a huge fold out rack of catchers. I looked at a vehicle like that, the panels were folded in the flat bed and you had to assemble them in the direction of the sun. It sounded fun, but impracticable, and also we might need our vehicle when the sun is not, and has not been shining.
This is a different version from the usual set which was issued by W.D. & H.O. Wills in 1929. And though it is usually quoted as having also been issued in 1929 too, there is no proof of this. We know that Eagle Bird operated from 1908 until 1929, through China India, Malaya and Siam. And there is another curious thing about this set as well, look at the top of the front, where it says "Romance of the Heavens" - it is the only one of the Eagle Bird sets to have a title, all the rest were given adopted titles by early cartophilic researchers, entirely based on the subjects they depicted.
In our Wills reference books this set is an afterthought, seemingly, as they list the home issue, the New Zealand issue and the set that was anonymously issued overseas. Then they say "Similar by B.A.T. Eagle Bird". I do not know how "similar" or how different it is, but hopefully someone else does and can fill us in on the info.