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… Writing in the May edition of Scientific American, economist Jeffrey Sachs showed us the road to clean energy. On Tuesday, Himanshu Pandya at Financial Nirvana told us about a shorting opportunity in First Solar. More on overpriced solar stocks below! On Wednesday, Shruti Basavaraj and Katrina Chan at The Motley Fool informed us that the Motley Fool was going green. Not to be outdone, Annika Mengisen at TheStreet.com let us know, on Friday, that green was good. Happy Earth Day everyone! On Thursday, Katherine Bourzac at Technology Review told us about a new biofuel: propane. She also told us about a new company: C3 BioEnergy. On Thursday, Neal Dikeman at Cleantech Blog warned us that an old Nigerian scam was moving into solar. Unsuspecting internet users beware! On Friday, Jennifer Openshaw at TheStreet.com urged us to save money by going solar. But the title is a bit misleading – she’s actually telling us to go solar to make money! On Friday, Dan Lewis at AEI made the bear case for China. With the valuations of certain unnamed Chinese solar companies being driven to impressive heights, this is a warning you are likely to hear more and more in the next few weeks. For those who have a subscription, the WSJ ran a piece on that exact topic today.