Why it It will work: By converting the sugars found in pant cell walls into fuel, the US could reduce petroleum consumption by 30 percent.
Why it won't work: The enzyme required to convert cellulose biomass into sugar is still too expensive, and current pretreatment processes waste too much sugar. Bad ROI.
Why it will work: Cheaper to produce than gasoline,, and now technologies are reducing the amount of fossil fuel required to make it.
Why it won't work: Converting the US's entire corn crop would produce just 12% of the nation's vehicle-fuel needs and emit only 13% less greenhouse gases.
Why it will work: An MIT report found that the US could produce 100 gigawatts of electricity by 2050 by tapping the heat found in subsurface rock.
Why it won't work: It's hard to access that rock without inadvertently causing seismic activity. Solving the problem could cost $1 billion.
Why it will work: At the current production rate, US coal reserves will last for 200 years — and that's not counting potential reserves that we can't yet tap.
Why it won't work: Turning that coal into liquid fuel requires vast amounts of water, an increasingly precious resource. Coal is also dirty and polluting.
Why it will work: Zero — carbon — emitting next — gen reactors promise 7 to 17 percent higher efficiency than traditional plants, and they're much less likely to melt down.
Why it won't work: Nukes are a political third rail; nobody wants a reactor in their backyard. And there's no fully safe place to put spent fuel.
Why it will work: A coming silicon glut will drive down the price of photovoltaic cells. New, thin — film technology could make the method even cheaper.
Why it won't work: Highly refined silicon panels may never be as inexpensive or productive as fossil fuels. Without continued government subsidies, solar could die.
Why it will work: Underwater generators can harness the power of tidal motion, potentially costing less than traditional dams and causing less ecological harm.
Why it won't work: Only 40 sites on Earth offer tidal ranges greater than 16 feet, the minimum to make electricity. And those will work for only 10 hours a day.
Why it will work: Longer, lighter blades have helped double turbine efficiency. Wind at next — gen offshore installations is 90 percent more powerful than on land.
Why it won't work: Where wind is, people aren't. No one has come up with economical transmission and storage solutions for this far — flung, intermittent power supply. (Source)
Of course, some of these solutions, like wind and solar, are available to individuals, but they do nothing to alleviate the societal needs and the following social and economic collapse that is sure to happen. This is nothing new. Societies have always collapsed. People will survive, but it will be a very different world. This is entirely predictable, given that catastrophic events preclude huge shifts in consciousness, perhaps the price of admission to the global shift many have been waiting for....but it's gonna be painful.