Also, why are so many people so willing to project forward socioeconomic problems like global climate change or Peak Oil forward for decades, but then try to prove their points that we are doomed by looking at technological reports on solar energy payback from ten or twenty years ago often prepared by those opposed to the technology for financial reasons? 🙂

If we instead project forward any technical development trends, like for 3D printing and nanotech, in a couple decades we’ll all be able to print out solar panels in our home 3D printers that have energy payback time in days or weeks. 🙂 As well as print out more 3D printers to give to our friends and neighbors, as well as print out devices to recycle products or extract raw materials from soil, the air, or seawater. Why is it fair to discount trends like those (exponential growth of capacity and innovation), when we are projecting forward trends in oil use or global climate change? The world is a complex set of trends, some good from a current human point of view, some bad. Focusing on only a few can give you any result you want perhaps.

Still, there are also many other energy alternatives being developed, from solar-thermal, to biofuels, to cold fusion, to hot fusion, to wind, to geothermal, and so on. To extend what Julian Simon said, the empowered human imagination, directed in enlightened humane ends, is the “ultimate resource”.
http://en.wikipedia.org/wiki/Simon-Ehrlich_wager
http://www.juliansimon.com/writings/Ultimate_Resource/

So, it is hard to predict what the future will bring for sure. But we can talk, as Julian Simon did, about baselines based on what we know. In his book, he showed how conventional nuclear energy with fuel reprocessing could supply us with electricity at near current prices for thousands or millions of years.
http://www.juliansimon.com/writings/Ultimate_Resource/TCHAR13.txt

His next chapter after that is entitled: “Dying Planet? How The Media Have Scared The Public”

I’m not a centralized nuclear fan, but his point about considering it as a baseline in our worries about the future makes a lot of sense. How can Peak Oil be an issue when we can just use what we already know about nuclear to power our civilization? More on that:
http://www.phyast.pitt.edu/~blc/book/

I still prefer renewables though, because they are less centralized, and more potentially p2p. 🙂