My problem with a mega-watt satilite would be that some idiot would figure out a way to turn it into a beam weapon. ION drive? Way cool application for the mini-nuke.
So far as Ethanol goes, it's nothing more than an only slightly less harmful substitute in my eyes... it's still going to give off CO2 (the major green house gas) and another green house gas that comes in second right after CO2... water vapor. Not sure what the byproducts of combustion are for Methanol, but I believe its going to be a little more nasty. It's also tough on plastics and rubber so car manufacturers would have a serious change. In fact, right now, most owners manuals state that if you use either Methanol or Isopropyl alchohols in the vehicle, the warranty will be rendered null.
Big question would be when are we going to stop Oxydizing carbon based materials as heat source? If the mini-nuke can be made safe enough to put in my back yard, why not put an electrical outlet on it to charge up the car? Sure, since it's mostly free electricity, you could also crack some ionized water (NAOH as an ionizer in a semi-closed system, for example) to make some H2, but then there's that green house gas known as H2O vapor again. We've gotta find some way stop burning stuff...
Handful of tera-watt parachute generators in the Gulf Stream would do it with virtually no environment impact... no fish choppers (turbines), no ugly windmills, and it's basically solar/planetary-rotation driven. Would make the combination of Hoover Dam and Niagra falls look like a triple-A battery in comparison. Or dig a couple of "Project MOHO's" (drill past the Earth's crust to get some real heat from the Mantel, done on the ocean floor where the crust is thin) and we'd have all the electricity we'd need.
Of course, the boys selling oil, natural gas, and corn-squeezin's would squawk... 😛