Rooftop solar panels. (VCU Capital News Service)
One of the most exciting areas of energy technology today is storage. With wind and solar now the leading sources of new energy capacity in the U.S., maximizing their potential in the future depends on the development of storage solutions with different durations and applications.
We tend to think first of batteries, a form of chemical storage, but energy can also be stored thermally (for example, in molten salt at concentrating solar facilities) or using gravity (think of hydroelectric dams and pumped storage). Compressed-air storage, flywheels, and hydrogen fuel cells all offer promise.
Other new technologies are a little more cutting edge, one might even say niche. Take, for example, an interesting gravity-based system designed by Dr. April Iocus, a professor of theoretical engineering and self-described tinkerer. Dr. Iocus turned her entire house itself into an energy storage system.
Solar panels cover the roof of the modest Cape Cod. During the day, energy from the panels powers a hydraulic system to lift the house off its foundation. As the sun sets, the house gradually settles back down, in the process putting out more than enough energy to keep the HVAC, lighting and appliances all humming along without a hitch.
“Gravity is a free resource,” Iocus points out. “Like wind and solar, it’s available everywhere and won’t run out. It’s also really strong, so it’s ideal for holding energy and then releasing it again. It takes a tremendous amount of energy to lift a house even a little way off the ground, so even on cloudy days the system holds a lot of stored energy.”
Home gravity storage has a number of advantages over other storage methods. Energy is stored on site so it requires no transmission lines, and there are no toxic chemicals or fire hazards, as there are with batteries. Batteries also have a limited useful life, whereas a gravity-powered system can be expected to last as long as the house does.
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Iocus concedes that the design of GravityHouse™ did pose other challenges. Indoor plumbing was one. Currently the house connects to city water and sewer only at night, when the building comes to rest on its foundation. During the day, holding tanks serve the family’s needs. Although this works perfectly well, Iocus says, “It drives the housing code people crazy. I’m working on a solution involving coiled pipes. Picture giant springs, and you get the idea. I’m ready to install them as soon as I work the kinks out, literally.”
Ingress and egress posed another problem initially. On a clear, sunny day in June, the house may rise as much as 12 feet off the ground by late afternoon. The solution: purpose-built staircases by the front and back doors offer landings every couple of feet. From the right landing it is just a modest step up or down to reach the level of the door.
Iocus also recounts one near-catastrophe. The hydraulic system was not designed with a stop at the top. One June day a solar flare increased the surplus electricity coming out of the solar panels so much that it lifted the house clear off the hoist. The house hovered in the air a full minute while Iocus frantically cranked the air conditioning to maximum output. Gradually, the house settled back onto the hoist—fortunately, without even a millimeter shift in position.
“I was just lucky. If there had been even a breath of wind, or if I had so much as sneezed, well. . . .” Iocus has since installed a stop to make sure the same thing can’t happen again.
Following the success of GravityHouse™, Iocus is turning her attention to other projects. She is particularly excited about potential new uses for the enormous natural gas transmission pipelines that stand to be abandoned as Americans stop using fossil fuels. Iocus says larger-diameter pipelines could be repurposed for human transportation.
“We’ve got pipeline infrastructure and compressor stations already in place all over the country,” she notes. “And a 42-inch pipeline is big enough for a human to sit comfortably in a transport pod. It’s an obvious solution.”
Iocus is currently in talks with Elon Musk to secure financing.
Happy April 1.
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