Any device which generates electricity may require testing. This can be for prouct development, production line testing, product demonstration, commissioning of a new installation or for periodic service, maintenance or trouble shooting.
Although the most common use of load banks for testing is with engine generator sets, in-fact, any device which generates electricity may require a load bank for testing, service or calibration. This includes UPS, batteries, power supplies, fuel cells, solar cells, wind turbines, hydro-generators, etc.
A load bank provides a stable, known, controllable and relatively “harmless” load for these purposes. That is, if the performance of the generator is not known, it is beter to evaluate the performance with a load bank than with critical facility loads.