Protection, Control, Automation, and Integration for Off-Grid Solar-Powered Microgrids in Mexico

Oct. 4, 2016
Learn about how Mexican utility Comisión Federal de Electricidad (CFE) used renewable energy systems to provide electric service to rural communities that are located far from the grid.

In 2012, Comisión Federal de Electricidad (CFE), the national Mexican electric utility, provided electric service to 98.11 percent of the country.  However, rural communities in Mexico (mainly isolated indigenous communities) still lack electric service. Conventional electrification is neither practical nor affordable for these communities that are isolated and located far away from the electric grid. CFE launched the White Flag Program (Programa Bandera Blanca) with the objective of using renewable energy systems to provide electric service to these communities. This program is focused on providing electricity to communities with more than 100 inhabitants. The levels of solar radiation at different locations were measured to determine communities suitable for the installation of photovoltaic systems. Based on these results, in 2012, the CFE White Flag Program launched two projects to provide electric service to two communities belonging to the Huichol indigenous group, Guásimas del Metate and Tierra Blanca del Picacho, both located in the mountains near Tepic, Nayarit, Mexico.

Greenergy, a Mexican company that designs and builds photovoltaic power plants, was responsible for the design and construction of these two solar-powered microgrids that had to comply with CFE special requirements. Both systems are currently in operation.

The microgrids consist of a photovoltaic system, a step-up 0.22/13.8 kV transformer bank, and a radial 13.8 kV  distribution network. Each microgrid includes an integrated protection, control, and monitoring (PCM) system. The system collects and processes data from the microgrid substations and sends the data to the supervisory control and data acquisition (SCADA) master of two remote CFE control centers. The system includes local and remote controls to operate the microgrid breaker. CFE is studying the possibility of interconnecting neighboring microgrids in the future to improve service availability. The specific requirements, solutions, and operational experiences from these pioneering projects serve as a guideline for future solar-powered microgrid projects in Mexico. This paper describes the solar-powered microgrids, their PCM systems, and the operational experience accumulated thus far.