Installation and operation of a large scale RAPS system in Peru

Abstract

In 1997, International Lead Zinc Research Organization Inc. (ILZRO), Solar Energy Industries Association (SEIA), and the Ministry of Energy and Mines (MEM) of Peru signed a Memorandum of Understanding to facilitate the installation of hybrid remote area power supply (RAPS) systems in the Amazon region of Peru. Many remote villages in this vast region have either no or limited electricity supplied by diesel generators running a few hours per day. Subsequently, ILZRO sponsored the engineering design of the hybrid RAPS system and SEIA supported a socio-economic study to determine the sustainability of such systems and the locations for pilot installations. In mid-1998, the Peruvian government approved the design of the system. ILZRO then began efforts to obtain governmental and inter-governmental funding to supplement its own funds to underwrite the cost of manufacture and installation of the systems in two villages in the Amazon region. Additional major funding has been received from the Global Environmental Facility (GEF) administered by the United Nations Development Program (UNDP) and from the Common Fund for Commodities (CFC). Funds have also been received from the US Department of Energy, the International Greenhouse Partnership (Australia) and the Peruvian government.The RAPS system consists of modules designed to provide 150kWh per day of utility grade ac electricity over a 24h period. Each module contains a diesel generator, battery bank using heavy-duty 2V VRLA GEL batteries, a battery charger, a photovoltaic array and an ac/dc inverter. The batteries and electrical components are housed in modified shipping containers. The modules can be installed with a new generator or retrofitted to an existing generator. The charging and discharging regime of the batteries has been recommended by a study carried out by CSIRO, which has simulated the RAPS operation. The system will employ a partial-state-of-charge (PSOC) regime in order to optimize the life of the batteries, which have a projected life of 8–10 years. A remote monitoring system will consist of a satellite link between each of the remote area power systems and one or more central hosts. The system operator will be able to obtain actual operational status of the system and will be able to change set points and to force operation of certain functions in order to test the system.Preliminary cost analyses indicate that such RAPS systems are more economically attractive to provide electricity to remote villages than other alternatives, including 24h diesel generation and grid extension.The past 5 years have provided a number of lessons learned, particularly related to dealing with government agencies in a developing country, overcoming logistical problems such as shipping long distances and dealing with difficult climate and terrain. Despite difficulties encountered, the promise of RAPS systems as a rapidly growing market for lead-acid batteries appears to be bright given the demand for sustainable remote electrification.