Most Alternative Fuel Technologies Have Roots in Long-Ago Discoveries; Scarcity of 'Killer Apps' Slows Progress
PEORIA, Ariz. -- As light filled the sky on a recent morning here, a handful of giant mirrored dishes were being prepared to track the sun and ultimately feed solar-generated electricity into the Phoenix area.
High-tech marvels, the solar dishes look like three-story-tall mirrored flowers atop steel stems. But at the heart of each dish is a very old-fashioned invention: a Stirling engine, patented by a Scotsman in 1816, decades before the diesel or internal combustion engine.
The cutting edge of renewable energy is littered with long-established ideas such as the Stirling. From generating power from the wind to harvesting liquid fuel from algae, some of today's most promising new technologies are actually quite old.
In Energy Innovation, Everything New Is Old Again - WSJ.com