In the hunt for ever more reliable and efficient green energy production, the Australian National University (ANU) has developed a solar dish with an incredibly high sunlight-to-steam conversion rate. That's right, steam. Instead of photovolatic solar panels, which convert the sun's rays directly into electricity, the so-called "Big Dish" reflects them back at a receiver, suspended in mid-air, which converts water into steam. The gas can then be used to power a motor, or stored for long periods as molten salts. The latest breakthrough? A new receiver that's 97 percent efficient.
"We believe (it) to be the world's most efficient solar receiver," Dr John Pye, from ANU's College of Engineering and Computer Science said. The solar concentrator dish at ANU is the largest of its kind, measuring 500 square meters. The reflectors are able to focus the power "of 2,100 suns" onto the receiver and heat the water to a scalding 500 degrees Celsius. The team's new receiver module uses a "top hat" design with a small opening and a wide, catch-all brim. Tiny pipes are positioned on the outside, wrapping inwards, to catch the sunlight before the water travels up inside the "hat."
"Ultimately the work in this project is all about reducing the cost of concentrating solar thermal energy," Dr Pye said. Our aim is to get costs down to 12 cents per kilowatt-hour of electricity, so that this technology is competitive." If they achieve such a feat, the technology could be used to fuel power stations, lowering humanity's carbon footprint in the process.