Salt Lake Tribune: Solar and wind power sound like great, environmentally clean ways to generate electricity, don’t they? But what happens when the sun doesn’t shine and the wind doesn’t blow? It’s a question often posed by skeptics. The answer, according to a local environmental group, is compressed air storage: When excess electricity is generated, it is used to pump compressed air into underground caverns. When electricity is needed, the air is released, heated and used to drive generators. “It’s like charging…