"For the first time in modern history, clean-energy technologies are becoming cost-competitive with their dirtier counterparts," write the authors of a new report, "Clean Energy Trends 2006," released today.

Energy Priorities obtained an advance copy of the report, published by Clean Edge, Inc. It projects that markets for biofuels, photovoltaics, wind energy, and fuel cells are poised to expand four-fold in the next decade, growing from $40 billion in global revenues in 2005 to $167 billion by 2015.

Following the firm's Clean-Tech Investor Summit in February, Clean Edge founders Ron Pernick and Joel Makower on Monday unveiled the report, including their annual forecast of the top five clean-energy trends. Here they are:

• Clean Energy Becomes a Security Issue
  
• Innovation Stretches Silicon for Solar
  
• Renewables Cross a Tipping Point
  
• Flex Fuels Gain Power and Speed
  
• China and India Loom Large

The report's annual venture data includes energy tech's share of overall VC investments in the US, the number and size of US energy-tech deals, and a breakdown of energy-tech investing by subsector.

As with almost every forecast these days, China and India figure prominently. With 40 percent of the world's population, the report says, these countries could accelerate the growth of clean energy.

"The report names five companies to watch in 2006, related to these two regions of the world: Enova Systems, Selco, Suntech Power Holdings, Tata BP Solar, and Vestas.