Doubling will not and cannot continue. Just like you can double your savings every day for a limited time if you start at a dime, the math quickly catches up with you. As you say, do the math. You can't go a month doubling your saving every day starting with a dime, it gets into the millions of dollars. The low hanging fruit (the first dimes) are pretty much going to be picked quickly.
Much easier to rely on solar panels in Southern California, than it is in Montana where there is snow cover and overcast skies 6 months out of the year. While solar may in fact be able to provide power for a single family home in San Diego, it isn't going to serve a high rise apartment complex in Boston.
A two or three hundred mile range on a small electric car is fine for commuting 10 miles to work, but it doesn't help when I need a truck to take a 200 mile round trip hauling a couple of thousand pounds of material. On top of that, those ranges that electric vehicles can obtain diminish quickly when you factor in mountain climbs, sub zero temperatures and the need for heat.
