Design and operation of a 50 kWp PV rural electrification project for remote sites in Spain

Abstract PV systems are already cost-effective for rural electrification of scattered houses and villages in sunny areas of the world. To increase the feasibility of a large scale application there are some aspects that need better understanding and improvement. Some are technological, but also organizational, social and institutional. The district of La Garrotxa (Catalonia, Spain), is a mountainous zone with scattered population, part of which is not connected to the electric grid. In order to provide this service, the local authorities promoted an electrification project of 65 sites with stand-alone PV systems, within the framework of the European THERMIE programme. A comprehensive approach has included the following aspects. Organizational: The contractor has been an association of users. After commissioning of the systems, operation, monitoring and maintenance of the plants are the responsibility of the association. Users pay a monthly fee and contribute to some maintenance tasks. Training has been provided to the users on high efficiency appliances and load management. Technological: A new PV power conditioning unit, specifically designed to simplify servicing, has been evaluated. Its main features are a modular inverter, with a sinusoidal wave, and power range of 1–4 kW, PV regulator with MPPT, a battery gauge (state of charge algorithm) and an integrated data logger for the operating parameters. The analysis of the experience gained through this project contributes to a better understanding of the interacting parameters in these applications.