It is a simple device that stores electricity from the grid in a battery and uses the DC (direct current) power from battery and converts it into AC (alternating current) that is used by appliances. Although interchangeably used, but Inverter and UPS are slightly different and we will explain that later in this post. Inverters are generally good if you want backup for small household appliances like lights, fans, TV, computers, etc. However these days’ bigger inverters can also support Refrigerators, Washing Machines and Mixer Grinders. But then adding these big appliances significantly increases the size of Inverter-Battery system and it is best if one can avoid using them on Inverter. Using inverters for ACs is strictly not suggested.
DG sets use the power of Diesel to generate electricity. They generate instantaneous electricity rather than storing it. They are good for larger loads. So if you want to run ACs, Refrigerators, Motors, etc on power backup, then using DG set can be a good solution.
Solar PV is slowly and steadily gaining popularity and is a great way to generate power backup. Energy from Sunlight is converted into electricity and stored in batteries. However the limitations of Solar Power are similar to that of regular inverters, so they are still not the best solution for bigger loads.