Tech companies have something hanging over their heads.Photo: The SharpteamAs I sit here at the Local 123 café in Berkeley on Earth Day, a dozen hipsters are transfixed by their Macbooks, their heads lost in the cloud. According to a Greenpeace report [PDF] released this week, all those presumably green and well-meaning digital workers-slash-slackers are contributing to global warming every time they update their Facebook status, scan their Twitter stream or check their Gmail. That's because all those apps live in massive data centers -- a.k.a. "the cloud." In the "How Dirty is Your Data?" report, Greenpeace analysts estimate data …

Google's Oklahoma wind farm will be built this year.Photo: Marcin WicharyIt's getting a bit hard to keep up with all of Google's green investments these days -- $168 million put into a big solar power plant project one week; $100 million for the world's largest wind farm the next. But this week's big money move -- the third so far this month -- is different. It also involves wind but is a power purchase agreement (known as a PPA in the utility trade) rather than a direct investment in a specific project. The deal with wind developer NextEra Energy Resources …

Germans invest their euros in clean energy. Why are Americans so stingy with their dollars? In the U.S., any policy that raises taxes on anyone or causes anyone to pay more for anything -- at least in a way that's visible or traceable -- has become verboten. It's axiomatic in American politics that you can't do it. The populace will revolt, right-wingers will demagogue you, you'll be driven from office. There was even an amendment in Congress last year that would have disavowed any policy that would raise energy prices by even a cent (and every Republican voted for it!). …

A new home in Germany.Photo: Tim FullerGermany has become a world leader in renewable power thanks in part to its Renewable Energy Act (EEG), which came into force in 2000. It established a feed-in tariff program that guarantees producers of carbon-free power an above-market rate of return for 20 years. EEG pays tariffs to solar PV, concentrated solar, wind, geothermal, biomass, hydropower, and landfill or sewage gas. The tariffs vary according to capacity and level of technological development; they drop every few years based on the latest costs and level of penetration. German electrical ratepayers fund the program through a small fee …

Here's a crazy idea: why not use the enormous geothermal resource under Japan -- which is after all sitting on a "ring" made of "fire" -- as a source of nearly always-on baseload power? I asked Alex Richter, an Icelandic financier of geothermal energy projects, how much geothermal energy $152 billion would buy. (That's the projected total cost of the cleanup of the Fukushima Daiichi power plant, and doesn't even include the cost of building and maintaining it in the first place.) Using a conservative scenario -- namely the cost of geothermal power in the U.S., which is more expensive …

The Notrees wind farm.Photo: Duke EnergyThey like to do things big in Texas, so it's no surprise that the Lone Star state will launch the world's largest wind battery storage project. Duke Energy is not a Texas company, but it owns the aptly named Notrees wind farm in the Texas panhandle. The North Carolina power giant is teaming up with an Austin area startup called Xtreme Power to install a 36-megawatt battery at the 153-megawatt Notrees Windpower Project near Kermit, Texas. That's one big battery. Such technology is likely to become crucial as wind farms become ever larger but erratic …

The Kogan Creek Power Station.Photo: Kogan Solar BoostAustralian Prime Minister Julia Gillard on Wednesday appeared at giant coal-fired power plant to announce that the Southern Hemisphere's largest solar project would be built in Queensland. Why, you may be wondering, would the PM travel to a remote 750-megawatt coal power station to make a big renewable energy news pronouncement? Well, coal is king in Australia, and the 44-megawatt solar thermal project to be built by Areva Solar at the Kogan Creek Power Station will generate additional steam to drive the coal plant's turbines. "By using energy from the sun with Areva's …

A rendering of the future Ivanpah solar plant. Photo: BrightSource EnergyIt's only Tuesday but two milestones have been reached this week in the long march toward a carbon-free future. On Monday, BrightSource Energy became the first solar power plant developer to complete the financing of a large-scale project in two decades. The United States Department of Energy finalized a $1.6 billion loan guarantee BrightSource's 370-megawatt Ivanpah Solar Electric Generating System solar thermal power plant now under construction in the Mojave Desert in Southern California. (The feds initially had pledged $1.37 billion but threw in another $230 million Monday.) As the …

Google has saved you from getting lost, running out of email storage space, and not knowing trivial facts about 90s TV shows. And now it’s going to help save you from a dystopian Mad Max future by investing in solar energy. The company just bet $168 million on solar tech, in the form of the Ivanpah “power tower” plant in the Mojave Desert in California, which should be finished in 2013. Power towers are simple: lay out an array of mirrors -- 346,000, in this case -- and aim them at a tower full of water. On a sunny day, …

The Seattle Sounders don't just have crazy fans. Their facilities have a 57.6 percent landfill diversion rate.Photo: Mike HPro sports may not seem like a natural ally for environmentalists. Players fly from Boston to Los Angeles and back for a single game. Leagues and teams convince cities to build expensive and often unneeded new facilities with taxpayer money. Fans clog up roads as they drive to games and clog up trash cans with hot-dog wrappers and beer cups once they arrive. But six teams representing six major North American sports leagues have kicked off a new effort to make themselves …