The folks at FutureBrief write:

"Companies promoting solar power and other alternative-energy concepts are rapidly attracting venture funding, research grants and, just as important, the interest of many of the tech industry's deep thinkers and influential figures. 'We have a huge energy issue in this century, and it will not be solved by policy. The only real solution is technology,' said Jim Plummer, dean of Stanford University's School of Engineering...." As energy prices soar, many companies are researching possible alternative energy sources."

Alternative energy sources have a long way to go before they'll even make a noticeable dent in our fossil fuel use. Still, the fact that economic drivers are now spurring more research is very promising. As News.com notes:

"The more immediate drivers for the interest in alternative energy today are technological improvements and declining costs -- in other words, qualities that appeal to the venture capitalists of Silicon Valley and others looking for new opportunities."

The rest of the News.com article has a very good round-up that covers some of the economics and history involved, the sector's investment totals, and a number of the companies and technologies doing work in this area.

Finally, Director Richard Smalley from the Carbon Nanotechnology Laboratory at Rice University offers a glimpse of what a future mixed energy infrastructure might look like.

UPDATE: FuturePundit has more.