A baby cow is called a calf. Adult male cows are called bulls. Adult female cows are called heifers until they give birth; after they have given birth, they are called cows.
As long as there is a fuel supply of natural gas or propane, a well-maintained backup generator will keep running. If the Generac generator is running on propane, with a 500-gallon tank, it should run 24 hours a day for over a week. How loud are they? Generac generators are very quiet.
The most popular Generac generator model produces 22kW, which is commonly installed to power the entire home, including all the most common appliances in a home, such as high-load central air conditioners, electric heaters, kitchen appliances, etc.