New Year 2020 While not as efficient per square foot as silicon-based solar cells, the new paint is so inexpensive, and can be applied to so large an area, that the gains far outstrip the one small disadvantage. Speaking of speakers, there is a new kind of refrigerator using a very loud loudspeaker in an enclosed chamber to compress and rarefact air to refrigerate items. It does not use CFC: it uses air. It is efficient and ironically, quiet in use. https://www.newyear2020guide.com
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