Today the nation’s largest solar power show, Solar Power International, opened with a rousing keynote session. Standing on the same stage that hosted the prime time Emmy Awards just a month or so ago, Rhone Resch, President of the Solar Energy Industries Association (SEAI) and Julia Hamm, President of the Solar Electric Power Association (SEPA) began the show by pointing out all of the celebrities who have installed solar power on their residences: Sheryl Crow, Brad Pitt, Leonardo DiCaprio and many more (they didn’t mention another big solar advocate, Larry Hagman, whom I had the pleasure of interviewing in July).

Resch highlighted some of the industry’s recent achievements such as the BLM fast track approvals that were recently made for more than 700 MW of utility-scale solar plants in California. He said that Suntech’s recent opening of its Arizona factory – a Chinese company opening a factory in the U.S. – was another industry accomplishment. Resch also told the crowd that solar installations have grown over 100% this year, with an expected 1 GW of solar installed in 2010.

But just after Resch highlighted all of the great achievements in the solar industry, he issued a stern warning. The industry has enemies and the enemies have deep pockets. Resch said that Big Oil spent $500 million to defeat legislation that would have created a national RPS and cap and trade. He explained that millions of dollars are being spent in California under Prop 23 to repeal that state’s RPS.

Resch urged the industry to act like a team – Team Solar. He said every member of the solar industry should join SEIA and contribute to the SEIA political action committee, pointing out that if everyone in the room gave $10, it would equal the amount of money that the oil and coal lobby has at its disposal to promote its own agenda.

The keynote offered a lot of firsts for me. It was the first I had heard that some experts say that 5 of the 10 biggest investors in solar will be utilities in the next few years. (Hamm said that.) And it was the first time I had heard industry spokespeople call for collaboration by smart, creative people to overcome the very real challenges of transmission and energy storage need to be solved in order for solar to scale up. (Not to mention, It was the first time I had been in such a comfortable seat for a keynote and the first time I had been in the Nokia Theater.)

But most interesting for me, it was the first time that I have ever heard such an “us verses them” call to action. In year’s past, the solar industry took the moral high ground against dirty fossil fuels, quietly confident that its environmental superiority would win in the end and that a transition to clean energy would come because it was the right thing to do.

Now the industry has woken up to the fact that there are those out there who want to see it fail. And opponents will do everything they can to stop solar from succeeding.

Game on.