Researchers have designed a 3D-printed electric car and a 3D-printed building that fuel each other. A demonstration of additive manufacturing, or 3D printing, and integrated energy, the project also uses a natural-gas generator to power the car's battery bank and the house's battery bank.
“We worked for the last nine months on this project to print a house and print a car and look at the energy distribution between the two,” says Martin Keller, director of energy and environmental sciences, Oak Ridge National Laboratories (ORNL), Oak Ridge, Tenn.
In the U.S., on average, a third of energy is used for transportation, a third is used to power the home, and a third is used to manufacture those homes, says Keller. “But there is no transfer of energy” between these uses, he notes. The average car is idle 94% of the time but, when operating, produces enough energy to power two homes, Keller says.
“Building solar-energy storage banks big enough to power a house is expensive,” says Keller, estimating the cost to be around 64 cents per kilowatt-hour. But using the car’s natural-gas generator to refill the building's smaller battery bank would solve peak power-usage problems, which are an issue only when the resident is at home. Using solar panels to charge both battery banks keeps the generator from constantly running and saves on energy usage.
Keller says Skidmore Owings & Merril, Chicago, designed the structure using additive manufacturing for its flexibility, and the team took advantage of that. “We changed the design while we printed the house,” he says, recalling that SOM changed the design during the manufacturing process because of printing difficulties. After the pieces were printed, the flexibility of additive manufacturing helped to solve other problems. “The custom-made aluminum windows didn't fit because the design changed, but we just printed a new frame for the windows—and it was fixed in five hours instead of five months,” says Keller.
The project’s innovation goes beyond 3D printing. “We developed the first bidirectional wireless charger that has level-two power charging and takes the same amount of time to charge as a regular plug-in,” says Madhu Chinthavali, director of power electronics and electric machinery, ORNL. While level one equals 120 volts, level two equals 240 volts. The wireless charging mat works like the Apple Watch’s wireless charging station, but the car battery can charge the house battery and vice versa. “This couldn’t have been done five years ago,” says Keller.