Generators are chosen based on the electrical needs of the loads to be operated, and the size and capacity required for the generator is determined by several factors, including:

1- The electrical load: The size of the required generator must be determined based on the size of the electrical load that is being operated, and this is done by calculating the total electrical capacity of the loads connected to the generator.

2- Type and configuration: The generator must be chosen that is commensurate with the type of electrical load connected to it, and this includes determining the type of electric current (such as alternating current or direct current) and determining the required electrical voltage.

3- Operating conditions: The generator must be selected that is commensurate with the operating conditions surrounding it, such as high temperatures or high humidity, and this is done by determining the ambient temperature and the temperature required to operate with high efficiency.

4- Efficiency and consumption: The generator must be chosen that is characterized by high efficiency and low consumption of fuel or other media used to generate electricity.

5- Noise level: A generator with a low noise level must be chosen, especially if the generator is used in residential areas or places that require relative quietness.

6- Cost: The generator must be chosen that is commensurate with the available budget, and the most efficient and cost-effective generator must be determined.

Care must be taken to choose the appropriate electric generator carefully, and to ensure that it is compatible with the actual needs of the electrical loads and the operating conditions surrounding it.