1 Scope

This part of IEC 62257 provides a method for describing the results to be achieved by the electrification system independently of the technical solutions that could be implemented.

The purpose of this part of IEC 62257 is to provide a method to assist designers of renewable energy systems, project contractors and project developers to design the electrification system for isolated sites while matching the identified needs. This part of IEC 62257 assesses the needs of the users and the different power system architectures which can be used for meeting these needs. In relation to the needs of the different participants to the project, functional requirements to be achieved by the production and distribution subsystems are listed.

In Clause 4, the functional requirements of off-grid electrifications systems are described. These include the micropower plant, distribution system for isolated microgrids and the user’s electrical installation providing power to their loads.

In Clause 5, the types of micropower plants that can be installed within an individual electrification system (IES) or isolated microgrid are described.

In Clause 6, resource assessment (solar, wind, hydro, biomass) and data sources (PVGIS, Global Solar Atlas, NASA POWER, etc.) are outlined.

In Clause 7, the requirement to undertake load energy assessment is described and includes the relationship between the available energy, the design of the system and the user’s expectation.

In Clause 8, the information that has been used in the design process and should be specified in any design documentation to allow the participants to select the equipment or component able to fulfil the functional requirements are listed.

To allow and facilitate the management of the micropower plant and the maintenance of the whole electrification system, some information is collected and monitored.

In Clause 9, the required measurement parameters for each component (PV, wind, hydro, genset, battery, inverters, controllers) to support operation and maintenance are listed.

The steps to follow this part of IEC 62257 when designing an off-grid electrification system are as follows:

Step 1: Conduct a resource assessment (see Clause 6). Step 2: Conduct a load assessment (see Clause 7).

Step 3: The designer uses the information obtained in the two assessments to determine the type and configuration of the micropower plant (see Clause 5) and to select or specify the micropower plant components (equipment) (see Clause 8).

Step 4: The designer should develop a monitoring plan that will support the ongoing operation and maintenance of the off-grid electrification system (refer to Clause 9).