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An Ancient Greek Weapon Could Become the Future of Solar Energy
Converting death rays into electricity
Some 2,200 years ago, the Roman Empire decided to take over Sicily, an island located in modern-day Italy. It was a strategic move against the Carthaginians, whose influence spread over the Mediterranean basin.
The invasion was supposed to be a picnic for Rome’s well-trained soldiers. What they didn’t expect was that a clever older man named Archimedes was about to unleash hellfire on them.
Historians claim that Archimedes devised a technology capable of emitting heat rays that burned battleships from a distance. Supposedly, the Greek mathematician used curved, highly polished shields to turn the hot Mediterranean sun into a deadly weapon. That’s how the tiny city of Syracuse managed to fend off the great Roman army for an entire year.
While the accuracy of the story remains questionable, the technology involved turned out to be very real. Scientists call it Concentrated Solar Power (CSP), and modern powerplants use it to produce electricity at increasingly lower prices.
“[CSP] is a fairly new development,” said energy expert and author Craig Shields. “What it essentially means is focusing the sun’s rays on a certain point or a certain line and using that heat to turn a turbine to generate electricity,” he continued. “The fact that [this tech] is new means there’s so much potential for the costs to come down.”
Comparing the two variants of CSP
The first flavor of CSP dates back to 1866, and it’s as close as it gets to the legendary Greek weapon. The idea is to bend mirrors in a U shape — also called parabolic trough — to focus sunlight onto a central line. Across this line, you place a tube pumped with a liquid, often water or oil, to capture heat.
Once the liquid absorbs enough thermal energy, you can use it to generate steam, which generates electricity via a turbine. The first documented application of this tech appeared in 1912 in Egypt. It helped farmers pump water into the desert…
