Tom Steyer is the founder of Farallon Capital Management and the co-founder of OneCalifornia Bank. He also created the TomKat Center for Sustainable Energy at Stanford University and is the co-founder of the Advanced Energy Economy organization.

Steyer spoke tonight at the Democratic National Convention in Charlotte, North Carolina.

In his speech, he noted that he is "a businessman, a professional investor, and a proud Democrat."

He said, "I think Mitt Romney and I share the same income bracket -- although I guess we're never going to know. But the reason I'm here tonight is that Mitt Romney and I don't share the same vision for the future, especially when it comes to energy. You see, this election is a choice -- a choice about whether to go backward or forward. And that choice is especially stark when it comes to energy."

Steyer has a net worth of more than $1 billion, according to Forbes.

We've spoken to Steyer in the past. He has suggested, "We need to push for the end of all subsidies." He has also said, "Include the 13 bucks a gallon [that are necessary] if you include the cost of keeping shipping lanes open." He noted, "Americans already know that renewable energy is the future. What they are worried about is the cost." 

Steyer took another swipe at Republican presidential candidate Mitt Romney and his party:

Take Mitt Romney's approach. Governor Romney would do nothing to reduce our dependence on fossil fuels and much to increase it. He would gut President Obama's investments in clean energy. He wants to keep giving four billion taxpayer dollars to oil companies every year -- the very same oil companies pouring millions into the outside groups backing his campaign.

Last week in Tampa, you didn't hear any plans that would create jobs now or a long-term plan for energy security. You also didn't hear very many facts. So here are a few: America's dependence on foreign oil is the lowest in two decades. Even as we've tightened our belts elsewhere, America has made record investments in clean energy technologies from wind to solar to biofuels. We're modernizing our electrical grid to harness more renewable power sources. We're doubling fuel-efficiency standards for cars and trucks. And domestic production of natural gas is at an all-time high -- natural gas, which, if developed safely and responsibly, could help bridge our energy present to our energy future.

And he stumped for Obama:

Or we could follow President Obama's long-term plan for the future for an economy fueled by a safe, secure, sustainable energy supply.  During the last several years, we've seen tremendous progress on new technologies that can make us energy independent and create thousands of jobs. This is about investing for the long haul, not for a quick-and-dirty buck. This is about taking control of our destiny by doing what Americans do best: out-innovating, out-thinking, out-hustling our competitors. And President Obama has put us on track to do just that -- making investments for the long term.

Big things are happening. Thanks to President Obama, America is laying the foundation for the way we power tomorrow. So here's my question for you:  Should we go back to the boom-and-bust, "drill-baby-drill," polluting energy policies of yesterday, or should we embrace an advanced energy economy that meets opportunity with innovation? Should we settle for an economy built on shifting and uncertain sands, or should we keep building an economy made to last? Governor Romney's road to the future will lead to dirty air and increasing climate volatility, uncertainty over energy prices, and less security, not more. President Obama's road to the future will lead us to energy independence, energy security, a safer and cleaner environment, and countless new jobs that can never be outsourced.

Steyer spoke on the basis of his record as a businessman:

Now, I say all this not as the head of Greenpeace or the Sierra Club. I say it as the head of an investment firm that has spent the last quarter-century crunching the numbers and making the tough calls. President Obama knows that advanced energy is America's future. And my bet, as a businessman, is that he's exactly right.

All day long, I make decisions about smart investments and risky gambles. That's the job of our president, too. President Obama is making the smart investments we need, and my vote for him is an investment in jobs today, energy security tomorrow, and a stronger country for my kids.

In our past interviews with Steyer, he's said that there's a distinction between renewable energy and advanced energy. Steyer views the shift from coal to natural gas and the focus on energy efficiency as part of this move to advanced energy. He said it's the "new way [that we will] generate and consume energy."