Almost all people are dependent on electricity. They use it for their fridges, lights, computers, heating… everything. Therefore when the power goes out, you are literally left in the dark. With an electric generator at standby, you know you can always move to your backup power and you wouldn’t have lost anything.
During a power cut your fridge as well as freezers would stop working, and all your frozen and refrigerated food will go off and probably start to mold pretty soon. If your business is with food and refrigerated goods, then a power cut can end up costing you hundreds to thousands of pounds/dollars.
If you are living in the country side then you will probably need electricity for your water supply as well. An electric generator can help you when anything goes wrong with the power as it can sustain everything electric that you have for as long as you need to get it all fixed again.
You can get generators in a wide range of sizes, the largest being for massive power plants that can be used for ages and generate huge amounts of electricity, to small domesticated ones that can generate enough power to home or business. Backup generators are extremely common for houses and businesses alike that would need a source of power in case the main power cuts out. And if its going to save you money then its an absolute must to have one.
Electric generators have advanced uses to petrol ones, they generate much more power, use very little or no fuel, and can be used over and over again for a long while. If you have a home or business to protect, and you need a source of backup power, then electric generators are key for you.