Decentralized Wind Electric Applications for Developing Countries

It is estimated that 35%-40% of the world's population does not have access to utility grid power. However, many developing countries have recognized the societal value of bringing electricity (and the related beneficial uses) to their rural communities. As a result, the growth in electric demand in developing countries far outstrips that of the developed world. Still, the cost of grid extensionsto rural villages and low-density population regions is generally economically unattractive and must therefore be heavily subsidized. The common alternative to grid extension is diesel generation because diesel generators are usually relatively inexpensive to install. Still, their operation and maintenance costs, as well as problems associated with operating them in remote, less-developedcountry locations, are well documented. In many remote village applications, hybrid renewable systems offer advantages in terms of economics, reliability, sustainability, and environmental impact. Because renewable resources are abundant and widely distributed, wind hybrid systems are appropriate for many remote electric applications, even at moderate annual average wind speeds (4 m/s). Thevariability and intermittent character of renewable resources usually requires the system to have storage or a back-up generation capability. Selecting the appropriate hybrid system architecture involves considering alternative subsystems, the level and variability of the associated resources, the current and future needs of the community, and, of course, the economic and financial aspects. Thetwo examples of wind hybrid installations discussed in this paper demonstrate the application of integrated renewable subsystems in meeting the electrical needs of two isolated communities in Mexico. While hybrid systems are currently being installed in many developing countries, the U.S. Department of Energy (DOE) is sponsoring a complementary research and development program to improve theperformance and lower the cost of hybrid village systems. The program is being carried out at the national laboratories (NREL, Sandia National Laboratories [SNL], and Pacific Northwest Laboratory [PNL]) and through subcontracts to the private sector and universities. It includes the development of innovative components, subsystems, systems, and computer models, as well as the performancemonitoring and evaluation of installed systems.