If the volume of new patents filed in an industry indicates innovation and future health, the future looks bright for solar energy.

The Massachusetts Institute of Technology (MIT) and nonprofit organization Santa Fe Institute recently released a report revealing that the number of patents for solar industry innovations increased 13 percent a year between 2004 and 2009.

The study, which examined patent filings back through the 1970s, found that the number of patents in the renewable energy industry far outpaced those filed for traditional fossil fuel exploration technology, especially since 2000.

Jessika Trancick, Assistant Professor of Engineering at MIT and report co-author, worked with other researchers to develop a database of energy-related patents issued in more than 100 countries between 1970 and 2009.

The database “gives you a view into innovation activity – who is doing it, and where,” Trancick said in an MIT communication.

The researchers found that new patents in nuclear technology were flat, while there were modest increases in new technologies for coal, oil and gas. Fossil fuel patents climbed from an average of 100 a year between 1975 and 2000 to about 300 a year in 2009.

Renewable energy technology patents, however, surged from an average 200 patents a year between 1975 and 2000 to more than 1,000 in 2009.

While patents for new solar technologies have surged 13 percent a year, new wind patents climbed even more aggressively at an average rate of 19 percent a year between 2004 and 2009.

Researchers found that patent trends were similar in the United States and abroad.

The study also found that investments in new technologies and new research pays off, even if it doesn’t develop into commercial innovation right away.

There was significant investment in renewable energy technology research and development in the 1970s and early 1980s following the energy crisis. But the funding dropped off dramatically afterwards, according to a report from MIT on the team’s research.

“Knowledge persists,” Trancick added.  “A lot of work was done in the ‘70s and ‘80s, a lot of effort was put in, and we’re still benefitting from that.”

While investment comes in cycles, the knowledge gained from that research isn’t lost, which Trancick said she finds comforting.

Some of that persistant knowledge has resulted in a massive influx of new patent filings for renewable energy technologies during the last decade.

The drive for new innovation has shifted from one of environmental concern to an economic and progressive one, Joel Makower, Executive Editor of GreenBiz.com told USA Today.

Now that companies like Google and Apple are investing substantial amounts of money in solar energy development, innovation and patent filings will likely continue, he added.  “This is not a warm fuzzy thing to do.  This has become a business imperitive.”