Green tech finds, 10/20/11

Underground skyscrapers, smart windows and more problems with natural gas drilling: Your green tech finds for the week.

Charge your car with your phone: Well, not exactly, but a new app developed by IBM and Swiss utility EKZ allows for better management of when your electric vehicle is charged and what sources of energy are used to charge it. Find out more in the video above. (via @greeneconpost)

The grain silo hotel: While not as green as it could be (because the structures used were built for the project), Silo Stay, a nine-unit New Zealand hotel built from grain silos, could inspire others to reuse these structures (as they’ve done up at Dancing Rabbit Ecovillage). (via @MotherEarthNews)

Mining pits become self-sufficient, underground skyscrapers: “Skyscraper” is probably the wrong word for this concept developed by architect Matthew Fromboluti of Washington University. Regardless, the idea would turn land damaged by surface mining into a sustainable underground city, complete “with its own power source, water recycling system and mechanisms such as a solar chimney to control the artificial climate.” (via Inhabitat and Grist)

Smart windows for more energy efficient buildings: We all know about insulated and double/triple-pane windows, but what about smart windows that could adjust the amount of light let into a building with the flip of a switch? They’re out there, and may come down in price as manufacturing ramps up around the US. (via @ecosphericblog)

Ready to recycle that old iPhone? With the new iPhone 4S coming out, you may be thinking about an upgrade, and that your phone may be worth money (or, at least, an Apple gift card). Apple is paying for any of its old products that qualify for reuse. (via coolerplanet)

The battle of the plug-in hybrids: Now that the Volt isn’t the only game in town (Toyota’s releasing a plug-in version of the Prius) John Gartner at Cleantechies takes a look at which of these vehicles is cheaper to operate. The answer: it depends.

And you thought water you can light on fire was bad: A study from New York State’s Department of Environmental Conservation has released a troubling (if somewhat preliminary) finding that wastewater from natural gas drilling is radioactive. (via @NRDC)

No doubt we’ve just scratched the surface here, so if you found something else in the green tech space, share it with us in the comments.