This part of IEC 62257 specifies the general requirements for the selection, sizing, erection 
and operation of generator sets in decentralized rural electrification systems. 
It applies to all low voltage combustion engine electricity generator sets energized by 
renewable energy such as biomass gasifier or biogas, or fossil fuel such as gasoline or diesel 
fuel, and designed for supplying electrical power to isolated sites used in systems as 
described in IEC TS 62257-2. 
This document is not an exhaustive resource for the design, installation, operation or 
maintenance of generator sets, but is more focused on recommendations to provide strategies 
on selection and criteria which may affect the use of such generation systems in a rural 
electrification project. 
Four cases of micropower plant will be considered as illustrated by Figure 1 to power a 
collective electrification system (microgrid) or an individual electrification system.  
– the micropower plant is composed of one generator set; 
– the micropower plant is composed of multiple generator sets, which may have a single 
energy source or multiple energy sources;  
– the micropower plant which is a hybrid energy system between one generator set and a 
Power Conditioning Sub-system (PCS) which is powered by other energy source including 
renewable energy source or energy storage; 
– the micropower plant which is a hybrid energy system between multiple generator sets and 
multiple Power Conditioning Sub-systems (PCSs) which are powered by other energy 
sources including renewable energy sources or energy storage systems.