The amount invested in clean energy technologies dipped slightly in the first half of 2006 compared with the last half of 2005, suggesting that the sector may be running out of the steam. According to London-based New Energy Finance, investment was down 1.5% to $19.3 billion, though it’s up 12% from the first half of last year. “Although the conditions for investment remain strong, the industry is nudging up against the limit to growth in various areas,” New Finance CEO Michael Liebreich said in a statement. Liebreich added that, following energetic growth from 2003 to 2005, the industry is “now facing a number of bottlenecks that must be resolved for growth to continue.” Leibreich says President George W. Bush’s “addicted to oil” comment in his State of the Union address in January fueled the current interest in celluosic ethanol technology.