ELECTRICITY COSTS OF PV- HYBRID vs. DIESEL IN MICROGRIDS FOR VILLAGE POWER

摘要

All over the world, many small villages, ranging from a cluster of a few houses up to a few hundred, are far away from the conventional electric grid. Electricity needs of rural villagers, related to their daily activities, can't be easily satisfied, due to the high economical costs -and frequently environmental costs- that involves grid extension. Following the example of larger villages, electricity supply is traditionally solved in many of these locations with a genset microgrid. This solution has a limited performance and high operating costs, mainly due to the fuel consumption, but is being unfortunately accepted as if it was the only option available, and often hoping that someday the "grid" of "real" electricity will reach the village. Usually electric service is limited to a few hours a day, with frequent cut offs due to technical problems or fuel supply. It also has to be considered the high environmental risks of fuel transport, storage and spills. One of the few advantages is that initial investment is low and that if there is lack of money for operating, one can simply reduce the operating costs by not operating the service. In an effort to further understand the competitiveness of PV-hybrid w.r.t. genset microgrids, investment costs and operating costs have been analysed for several case studies in the bolivian Amazonia region (Baures and Huacaraje), Argentina (Pastos Chico and Lagunilla), in Spain (Rambla del Agua and Escuain) and also insular Ecuador (Galapagos islands). This has allowed to identify the costs related with the quality of service technology and organization schemes. It has been observed that technology related costs are only part of the costs associated to standalone village rural electrification and a good operation scheme has significant cost as well; the life-cycle costs related to technology (operation and amortization) of PV-hybrids can be smaller than these of the genset-only. This is only certain if users are introduced to a load management and also high efficient appliances. Thanks to batteries, system configuration enables a culture of rational and efficient use of energy, obtaining global costs reduction.