Renewable Energy World is the conference where all forms of renewables come together once a year. The keynotes are inspiring and optimistic. The sessions are educational, technical, and full of experienced industry people. The real action is in the hallways and on the expo floor, where business is getting done.

For excellent coverage of Renewable Energy World, check out these blog entries and videos from the conference, and don't miss Stephen Lacey's Inside Renewable Energy podcast today. Here's my perspective on the event in a nutshell:

Cleantech finance

Finance is the big talk at Renewable Energy World this year. Normally REW is where technology, finance and policy converge. This year, finance is on the sidelines. Despite the serious economic setbacks that have beset the renewable energy industry recently, no one seems to be giving up. Capital may be scarce, but investor interest in renewables is abundant. Why?

Private equity investors say large-scale wind, geothermal and solar projects provide them with a reliable source of revenue. One panelist predicted that 60 to 70 percent of utility investment in new generating capacity in the next few years will be in renewable energy. (See "Utility scale" below.) Every project comes with a power purchase agreement extending years or decades ahead.

Cleantech manufacturers are positioned to profit from that boom. As for residential, the first wave of solar installations were mostly on the homes of high-income, well-educated homeowners, but new incentives are expected to expand the market rapidly. Investors see cleantech manufacturers as offering attractive profit potential to balance the riskiness of their businesses.

Utility scale

Several factors have been bringing utilities to the table for the past few years, and they're serious now.

Renewable portfolio standards are sweeping U.S. states and look likely on a national level. Carbon constraints are here regionally, and federal carbon legislation could be right around the corner. Fossil fuel costs have been volatile, pushing some utilities into bankruptcy and forcing bargain acquisitions. Finally, recent legislation made it possible for utilities to benefit from federal incentives for large-scale renewable energy projects. Utilities are at REW in mass, and they mean business.

Energy policy

The big uncertainty isn't whether capital will return -- most are certain it eventually will -- it's about how the regulatory environment will look a year from now. With the likelihood of some kind of carbon legislation, many wonder how the REC trading and cap-and-trade systems would meld, or work independently.

One certainty is that the stimulus package and bailout bill both gave renewables a big boost. New funds will be available to the sector, existing frozen funds will thaw, and tax credits were extended.

Above all, renewable energy is in the public awareness like never before. In Las Vegas it feels like the fossil energy world is steadily fading into the haze. Welcome to the new, hopeful, Renewable Energy World.