Many home all over the world especially in the developed world have stand by generators which are used when the power goes off either because of vagaries of nature or if something else happened that can put the lights off and they actually come in very handy. A generator for the home or a stand by generator assist in keeping the power on during any outage and it may be installed outside the house so as to keep the noise low and also prevent the fumes of the fuel they use to get inside the home and some are usually automatic and they switch on immediately the power goes off.
There are others which use diesel and petrol and these devices use electricity generation which makes conversion of motive power to power which is electrical and there are many sources which may include hand cranks, combustion engines, water turbines, gas turbines, and steam turbines. Some electric generators which use direct current have magnetic field which is static and there are reputable and experienced companies which provide all kinds of generators and they also do the installing of these generators.
Home generators are kept away from getting interfered with by rain torrents, ice or snow and most of these turn on automatically and one does not need to go outside to crank it up. They know what particular home needs and they go to the site so as to find out what range of power output the home may need and also what kind of generator is suitable for the home.
The stand by generators providers may go and see if the devices are working well and in some cases repairs are done such as when fluid gets accidentally in the generator and makes it not to start or when the battery gets drained and goes cold because of vast coldness or after a period of time. Generators produce hundreds of volts and some of them may actually have multiple of them which are connected in series so as to produce more electricity depending on the requirement of the home which can be as much as a million of more amperes because they have internal resistance which is low.
In some cases AC motors are utilized in generators so that energy which is mechanical is turned into electric current and this makes the rotors to run fast than they would if the method was not used and this is the technology that is used to make homes use normal rates of electric current without having to change some items to suit the electricity that is needed.