Presuming that you're talking about the permanent kind that turn on as soon as your power goes out. These are called home backup, emergency or standby generators. One of the first questions you need to answer is if you're going to use liquid natural gas (LNG), liquid propane (LP), or deisel as your fuel. If you already have natural gas coming to your home then this is probably your answer. If you don't then LP is usually the next best fuel, provided there are local companies that can keep your tank filled. Deisel is generally not a good choice because you need a large tank and the fuel can absorb water over time and cause problems. As far as brands go, Generac and Kohler are both excellent and have a long history in the industry. If you're thinking of a portable generator that can be plugged into your home and will automatically turn on when there's a power outage, then I'm not aware of such a thing. But that doesn't mean the don't exist. You'll just have to do some research.
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Generac Guardian generators do that. Home Depot can set you up with a in home quote. They have to be installed, as they are not your normal generator.
Home Depot Carry's them . Must be installed professionally by electrician
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