Researchers at Idaho National Laboratory, along with partners at Microcontinuum Inc. (Cambridge, MA) and Patrick Pinhero of the University of Missouri, are developing a novel way to collect energy from the sun with a technology that could potentially cost pennies a yard, be imprinted on flexible materials and still draw energy after the sun has set.80% efficient harvesting of infrared energy. If this pans out, this hasn't just made solar the default choice for new energy, but it's possible that we could double the available power from existing thermal plants without increasing fossil or uranium inputs.
The new approach, which garnered two 2007 Nano50 awards, uses a special manufacturing process to stamp tiny square spirals of conducting metal onto a sheet of plastic. Each interlocking spiral "nanoantenna" is as wide as 1/25 the diameter of a human hair.
Because of their size, the nanoantennas absorb energy in the infrared part of the spectrum, just outside the range of what is visible to the eye. The sun radiates a lot of infrared energy, some of which is soaked up by the earth and later released as radiation for hours after sunset. Nanoantennas can take in energy from both sunlight and the earth's heat, with higher efficiency than conventional solar cells....
The team estimates individual nanoantennas can absorb close to 80 percent of the available energy. The circuits themselves can be made of a number of different conducting metals, and the nanoantennas can be printed on thin, flexible materials like polyethylene, a plastic that's commonly used in bags and plastic wrap. In fact, the team first printed antennas on plastic bags used to deliver the Wall Street Journal, because they had just the right thickness.
Most thermal plants (coal, gas, nuclear) are between 30-40% efficient. This throws away most of the energy as waste heat. The conventional way of getting around this loss is by building a CHP network -- piping the waste heat in to other buildings instead of heating them directly. But if you don't have a steam network handy, the investment can be daunting.
If this nanoantenna technology turns out to be legit (please, let it be so!) that means that every power turbine in a thermal power plant is going to be rapidly obsolete. As one striking example, going to 80% heat conversion would double the output of Ontario's nuclear reactors, meaning that they alone could power the entire province's electrical demand. Or, better idea, Ontario could phase out its nuclear power plants (which will still be old, expensive and wasteful) slowly, while the remaining stock provide double output to cover any shortfall -- while the growing solar sector provides a growing base. Throw in the hydroelectric power and Ontario would be back to having a power surplus for the first time in decades.
The other interesting thing we're seeing here is the potential for the economics of solar power to flip -- solar power would be the cheapest power available, instead of being the most expensive. Fuel and labour costs would make biofuel thermal plants more expensive, but kept around for reserve power.
Add in those silicon nanowire batteries for energy storage, and we're close to having this whole energy thing licked.