New Setting Idea from CNN... a modern earth out of oil.

[Brother MacLaren]

I don't buy into the bit where Solar will power the world, we would have to convert a significant potion of the earth's surface to this task. Destroying natural environments and reducing agricultural land. To make the US completely sustainable by solar power would require us to convert 40% of our land mass into solar collectors. This is a terrible prospect, and ultimately too expensive to build or maintain.

No, the cars are not indicative of the potential of solar. The cars, you see, have to carry their solar arrays with them, so you have a real limitation in array size. If you were serious about it, you'd use larger stationary solar arrays to charge electric vehicles (perhaps lithium-ion batteries) or electrolyze water into hydrogen. It's not easy but it is possible. Again, we might have to make do with less range (the major drawback of EVs) but that isn't a civilization-destroyer.

I don't know where you got that figure of 40% of our land mass. Our primary energy consumption is about 100 quadrillion BTU per year. Total - fuel for electricity production, transportation, home heating, industrial processes, everything. The Desert Southwest gets about 2 quads per 100 square miles. Assuming a 12.5% conversion efficiency, we would need about 40,000 square miles, or a square 200 miles on a side. (For electricity alone, it would be about 10,000 square miles). That's a lot, but the land area of the US is over 3.5 million square miles. So the area I'm talking about is just over 1%. You put it in the Desert Southwest and you aren't sacrificing prime agricultural land. Some natural habitat is sacrificed; so what? Even greenies like me are pragmatic, some desert getting industrialized is better than an apocalypse. (Alternatively, you'd have about 60,000 mi2 of solar panels spread out around the country, with some in areas with less sunlight.) As for "too expensive to build or maintain," you need some hard numbers to back up that assertion. And I'm not seriously suggesting we run everything on 100% solar. There's also wind, hydro, geothermal, wave, and other options. All have some drawbacks (what doesn't?), but all of them work.

Coal is quite dense and can be processed into liquid fuels, such as Fischer-Tropsch diesels. I suggest you read up on the work of Bob Williams at Princeton or some of the work from South Africa. I'm not as familiar with the energy return on coal mining, but I do know that its transportation is relatively easy and fuel-efficient (trains). I've heard of Pimentel's conclusions on ethanol - some agree with him but there is no consensus - but that is why I suggested cellulosic ethanol. Lower energy input for same energy yield.

I don't pretend it would be easy or cheap to switch off of oil, but it would be technically possible. And, yes, this is what I do for a job.

 

[WayneLigon]

Each year we race little solar powered cars across the nation. Each year it is a joke compared to the gasoline cars that pass them like they are standing still.

You know, no-one ever said that roaring along at 100mph was some sort of right. People will adjust as they need to, particularly when there is no other choice for them. They adjusted for the most part to a 55 mph speed limit. If they had to adjust to cars that move at a max of 25-30 mph, that might be a good thing. Fewer accidents, it would limit urban sprawl and force a revitalization of the inner cities, reawaken train and urban rail infrastructures; people might even work from home more. It might be the thing to put the brakes on the more stress-filled aspects of modern life.

 

[Creamsteak]

People need to do more walking anyway, at least where I live.