Renewable Energy Sources for Power Supply of Base Station Sites

Abstract
An overview of research activity in the area of powering base station sites by means of renewable energy sources is given. It is shown that mobile network operators express significant interest for powering remote base stations using renewable energy sources. This is because a significant percentage of remote base station sites on the global level are still diesel powered due to lack of connections to the electricity grid. Besides huge expenses that mobile operators pay for diesel fuel and its transport to base station sites, it is pointed out that such base station sites represent major pollutants due to enormous green-house gas emissions. Since base stations are major consumers of cellular networks energy with significant contribution to operational expenditures, powering base stations sites using the energy of wind, sun, fuel cells or a combination gain mobile operators’ attention. It is shown that powering base station sites with such renewable energy sources can significantly reduce energy costs and improve the energy efficiency of the base station sites in rural areas. In addition, technical descriptions of the different power supply systems based on renewable sources with corresponding energy controllers for scheduling the flow of energy to power base station sites are discussed. According to the presented, hybrid systems which combine different renewable energy sources outperform those with only one energy source, and depend on the configuration of base stations installed on a particular site, such systems can offer autonomous functionality throughout the year.