It’s official: 2008, while being generally miserable for many business ventures, was a banner year for cleantech.

The Cleantech Group reports that worldwide cleantech investments last year soared to a record high of $8.4 billion (US). It was the sector’s seventh consecutive year of investment growth.

Whether that trend can continue into an eighth straight year in 2009, though, is uncertain. The Cleantech Group’s numbers show investments dropped considerably in the last quarter of ‘08, down some 4 percent over the same period in 2007.

Still, added executive chairman Nicholas Parker, money isn’t the only way to assess progress in an industry. He noted that 2008 marked a “quantum leap forward” in cleantech skills, innovations and demand and predicted that this year can expect to see further advances “in terms of imagining what’s possible.”

As for last year’s cleantech leader? It should come as no surprise that it was solar by a mile. Solar-energy companies nabbed about four of every 10 dollars invested, while increasingly maligned biofuels came in a distant second, attracting 11 percent of the pot compared to solar’s 40 percent. Transportation and wind-energy placed third and fourth, respectively.

Money is likely to be tougher to come by in 2009, so companies that hauled in cash last year will need to watch their bottom lines more closely than ever. Still, who wouldn’t rather be a member of the cleantech club than Detroit’s Big 3 (or, as The Truth About Cars cheekily calls them, D2.8) these days? (Though, if you count US taxpayers’ dollars, the auto club did recently nab $17.4 billion in pocket change.)

Tags: biofuels, cleantech, investments, solar, transportation, wind