Solar Powered Flying Drones  

Powering people's homes sustainably isn't the only area that power savings can be made in. If you want to run an efficient surveillance state or continuously monitor potential enemy territory in a "Forever War" over energy, then running your spying machines on solar power may also be attractive.

DefenseTech talks about the development—somewhat inevitably, I would think—of solar-powered flying drones, able to stay in the sky and monitor enemy troop movements indefinitely. A test model from AC Propulsion [pictured] has gone up for 48 hours straight and was only landed because the human operators got tuckered out.

Military uses aren’t the only thing a long-term solar-powered drone could be handy for, either, as people continue to talk about using similar technology as roving cell phone towers.