New solar dish harnesses power from heat – at a size and cost that make soaking up the sun even more attractive.
Melanie Stetson Freeman – Staff
Out on a lawn at the Massachusetts Institute of Technology with joggers and traffic passing nearby, Spencer Ahrens is demonstrating what looks like either the future of solar power – or perhaps a death ray.
Thrusting a 12-foot board up into the air in front of a large mirror-covered satellite-type dish, Mr. Ahrens, an MIT graduate student, waves the board, looking for an elusive sweet spot where reflected sun rays converge.
With three student teammates looking on, he steadies the board once its tip begins to glow. Shining white in the reflected solar rays, the wood suddenly bursts into flames. Students laugh as smoke billows in the breeze.
This burning-board trick may seem like a YouTube stunt, but it’s actually a visceral demonstration of a device with a serious purpose: to make super-cheap solar heat.
From garage inventors to government scientists, many have tried to make a solar dish that focuses sun rays to generate power. What makes this student project different is not that they’ve done it – but that they’ve done it so cheaply, building this dish with off-the-shelf parts.
“A lot of good people have built working dishes, but generally they’re more expensive, more complex, and harder to build,” says Matthew Ritter, an Olin College of Engineering student who’s also part of the team. “We use widely available materials – that’s our breakthrough.”
The student team has already formed a company – Raw Solar – that they hope will one day have an assembly line cranking out cheap solar dishes that individually or in large arrays could supply affordable heat to a college campus, suburban home, or third-world village.