A new report out from GTM Research and the Solar Energy Industries Association (SEIA) shows that solar power came an incredibly long way toward asserting itself as a key part of the U.S. energy mix last year.

The U.S. now has a total of 12.1 gigawatts of photovoltaic (PV) installations and 918 megawatts of concentrating solar power (CSP), enough to power 2.2 million homes.

Here are some of the other highlights from the Solar Market Insight Year in Review 2013 report:

• PV installations increased 41% over 2012 to reach 4,751 MWMW of CSP came online in 2013, increasing total capacity in the U.S. more than 80%.

• Solar accounted for 29% of all new electricity generating capacity, making it the second-largest source, exceeded only by natural gas.

• The cost to install solar fell throughout the year, reaching a new low of $2.59/W in the fourth quarter and ending 15 percent below the mark set at the end of 2012.

But these statistics don’t tell the whole story.

“Perhaps more important than the numbers,” says Shayle Kann, Senior Vice President at GTM Research, “2013 offered the U.S. solar market the first real glimpse of its path toward mainstream status. The combination of rapid customer adoption, grassroots support for solar, improved financing terms, and public market successes displayed clear gains for solar in the eyes of both the general population and the investment community.”

There’s certainly something to Kann’s claim that solar is on track to become mainstream, and some facts in the report bear this assertion out.

While California continues to lead the way, installing more than half of new solar energy generating capacity in 2013 (some 2,261 MW), red states Arizona and North Carolina were the second and third top states (421 MW and 335 MW, respectively). Given that political polarization and obstructionism have stalled progress on a number of important issues in recent American history, the fact that solar is appealing to folks on all ends of the political spectrum may speak more to solar’s bright future than anything else.