On Sunday, Sebastian Blanco at AutoBlog Green informed us that European biodiesel producers were intent on stopping the “US biofuel invasion”. I have long argued that the drive to ramp up biofuel production in the US was more about placating the farming lobby than it was about global warming or weaning America off foreign oil. It follows, then, that just like agriculture, generous biofuel subsidies are going to lead to frictions in the international trading system. The same is true, by the way, for Europe. To be continued… On Monday, Eli Hoffman at Seeking Alpha reported that the end of the ethanol boom could be in sight. Call this a bad week for US biofuels investors. Those with a subscription to the WSJ can read more about this here. On Tuesday, David Ehrlich at Inside Greentech (now part of the Cleantech Group) informed us that Comverge (NASDAQ:COMV) had acquired Public Energy Solutions. Consolidation is looming upon the cleantech industry, and I am happy to see that at least some of it is being driven by pure-plays. Energy Efficiency holds a lot of potential and Comverge is definitely a firm to keep an eye on. EnerNOC (NASDAQ:ENOC), Comverge’s competitor, also got busy last week. On Wednesday, EERE News reported on plans by eight utilities to boost their investments in energy efficiency over the coming years. See story immediately above for my thoughts on this space. On Thursday, Tom Lydon at Seeking Alpha argued that green ETFs were growing strong. Although I currently have no exposure to them, I am a big fan of ETFs as a cheap and convenient way for investors to play certainly themes like cleantech or global warming. The proliferation of cleantech ETFs over the past 12 months provides investors with ample choice as well as the ability to focus on sub-themes (e.g. North American alternative energy). On Friday, Jim Fraser at The Energy Blog told us that TECO was canceling a planned IGCC power plant because of uncertainty around carbon capture regulation. This piece of news is certainly reminiscent of the recent decision by TXU’s new owners to cancel the construction of several coal-fired plants in Texas. While this seems to support mine and others’ belief that there are material risks on the regulatory horizon for power gen firms with large exposure to coal, I view the current lack of clear policy direction as negative for everyone. It appears to me as though most companies and investors are now ready to move on this, but are finding themselves waiting for the Federal government to make up its mind. Sounds familiar?