I’ve watched a highly inter­est­ing doc­u­men­tary on the prospects of solar power today. Now an eng­lish ver­sion is avail­able on youtube:

Also highly inter­est­ing: The Car of the Future. Fea­tur­ing Opel P-1 exper­i­men­tal, a car that ran 375miles on one Gallon. That’s about 160 km per liter or less than 1 liter per 100 km….

Here is an arti­cle (again in dutch) that describes the way it worked (back in 1959).
Appar­ently, just as some other inven­tions, they were patented by shell and never got into fur­ther devel­op­ment. How come?