The Week in Cleantech is a weekly roundup of our favorite cleantech and alt energy blog posts and stories from across the web. If you know of a good piece that you think should be included here, don’t hesitate to let us know! This week, we particularly liked… On Monday, I received an email from the good folks at Lux Research informing me that they had just released a study looking into the 2006 cleantech VC investment numbers (PDF document). Before I had a chance to go over the press release, The New York Times had done a feature on the report. Alt energy bubble or no alt energy bubble, that is the question… On Monday, C. Scott Miller at BIOconversion Blog told us about the balkanization of the US renewable energy portfolio. In many ways, this is paramount to the success of alt energy. Different regions have different alt energy profiles depending on the availability of certain resources. As an investor, it thus makes sense to look for that fit in appraising the viability of a project. On Tuesday, Richard Widows at TheStreet.com showed us how alternative energy was powering certain high-performing funds. AltEnergyStocks.com often gets email queries regarding alt energy and cleantech mutual funds and ETFs – if you are one of the people wondering about those asset classes, you will find this piece interesting. The article also provides a short list of which alt energy stocks are most widely held by pooled capital. On Wednesday, the WSJ’s Energy Roundup informed us that a majority of Americans would agree to pay higher gas taxes if the money raised went to alt energy R&D. Paradoxically, however, most Americans aren’t willing to change their car purchasing or driving habits…go figure. On Wednesday, David Shukman at BBC News showed us a power station that harnesses Sun’s rays. Impressive!! On Thursday, Environmental Finance informed us that global carbon markets tripled in value in 2006. More on this a little later this week. On Friday, Biopact told us how biofuels would have a limited effect on food prices. You gotta love a contrarian opinion! On Friday, Rob Day at Cleantech Investing asked five questions. This is the sort of the short-and-sweet feature that can provide validation for your current model or a useful starting point for cleantech investing.