Turning Sunshine Into Megawatts

July 29, 2009 — -- For decades, Roger Angel has been reaching for the most distant stars in the universe. Now he's reaching for a neighbor, the sun.

Angel is a professor of astronomy at the University of Arizona in Tucson where he has pioneered innovative methods for creating huge telescope mirrors that now serve as the centerpieces in some of the world's largest observatories. He wants to use his own expertise, as well as that of his team of engineers and scientists who have done what many thought couldn't be done, to solve a daunting challenge.

Angel wants to capture sunshine that would otherwise fall on the Arizona desert and turn it into electricity. Not to recharge his cell phone or run his car. He wants to power the entire nation.

That may sound like a pipe dream, and maybe he can't pull it off, but Angel is not the kind of guy who can be easily dismissed. We met for the first time more than 20 years ago when Angel was tackling a problem that threatened to cripple the field of astronomy. The only way to look farther into the universe's backyard was to build bigger telescopes. Much bigger.

But that translated into mega bucks, because bigger mirrors were incredibly expensive to fabricate. So Angel came up with what seems like a simple solution. He built a spinning furnace.

He placed glass in a dish on top. It melted when the furnace heated up, and as the giant contraption began to spin the molten glass flared out toward the edges, forming the parabolic surface of a telescopic mirror.

It sounds simple, but in fact it was a technological triumph.

The huge furnace had to spin at exactly the right speed to achieve the proper shape, and it had to cool down at exactly the right rate to cause the molten glass to harden in the proper shape. Too slow and it could sag. Too fast and it could break.

The lab he supervises is using that technology to create the mirrors for what has been called the "next generation telescope," the 80-foot Giant Magellan Telescope that is to be built at the Las Campanas Observatory in Chile. The international telescope will have seven large mirrors that will act as one.