Weight is the enemy of efficiency. For electric vehicles, the heaviest component is the battery. To disperse the weight, Volvo has developed a new design that turns the body into a battery by incorporating supercapacitors in carbon fiber panels. This is a good idea, provided no car accident. Volvo and some other European companies are participating in an EU-funded project that combines nanostructured cells with supercapacitors into lightweight, eco-friendly energy storage. Supercapacitors have faster charge-discharge rates than current lithium-ion batteries used by carmakers (do not know what the Tesla chargers are doing), and they can store more in a smaller footprint energy of. Depending on the application, you can get 10-100 times the energy of a conventional battery from an ultracapacitor at the same weight. This is very attractive for car manufacturers. So Volvo and their friends concocted a nano-material, with nanostructured supercapacitors, and then clip it in a piece of carbon fiber and polymer resin board. Replacing the bonnet and torsion bar combination with a super capacitor plate allows Volvo's engineers to replace the 12-volt battery that powers the vehicle electronics while halving the weight. Taking this concept one step further, Volvo rebuilt a hood with this supercapacitor / carbon fiber board by turning it into a battery that can be recharged with a kinetic energy recovery system or a standard plug. Body into a battery: Volvo estimates that the replacement of doors, luggage, roofs and other components with this new material will reduce overall weight by 15%. However, it is not without risk. Although supercapacitors are considered energy storage artifacts, and capacitors and carbon fiber materials are relatively cheap. But they bring security problems. "By deconcentrating a lot of low-voltage areas in the car and affecting the disconnectors between the areas, the risk of damage is magnified," says Per-Ivar Sellergren, an engineer at Volvo. "Lighter components mean they can absorb less impact energy, but Volvo still requires it to meet the same impact test results of other Volvo cars." Safety and component replacement costs Volvo still need to be resolved, the product can not be short-term production.