Toronto Star: Pumping compressed air underground so it can be extracted later to generate electricity could prove one of the most effective ways in the short term for Ontario to add vast amounts of renewable energy to the power system, industry experts say. So-called compressed-air energy storage, or CAES, has been around for more than 20 years and while only two facilities have ever been built – a 110-megawatt plant in Alabama and a 290-megawatt plant in Germany – officials from New York, …