TechKnowledgey 2005

摘要

If you see anything revolutionary and interesting — or just plain cool — while surfing newsgroups, filtering press releases, or simply doing your job, drop me a line about it. Have questions or comments about what you read here in "Techknowledgey 2005"? Send that my way, too. You are, no doubt, familiar with direct electrical generation using photovoltaic panels, but there is increasing interest in Concentrating Solar Power (CSP) technologies, which use reflective surfaces to concentrate the sun's energy and convert it to electricity via mechanical means. CSP tech- niques are emerging as efficient and practical approaches for centralized power plants. One method uses a mirrored dish that continuously tracks the sun and focuses its rays onto a receiver, which absorbs the heat and transfers it to a Stirling engine. The engine then drives a generator. The Stirling engine, by the way, was invented by Swedish minister Robert Stirling in 1816 and thus predates gasoline and diesel engines. It uses an external heat source and a cooler to raise and lower the temperature (and pressure) of an internal working gas, thus generating reciprocal motion between a hot and a cold piston. Stirlings are quiet, efficient (approximately 30 percent solar-to-electric conversion), and non-polluting.