The study and review of energy efficient cooling techniquesfor telecom tower shelters

Telecom towers in India consumes around 16.5 billion kWh of electrical energy and 3.2 billion litres of diesel per year emitting 8.6 million metric tons of CO2 per year. The main reason for this high energy consumption and CO2 emission is that all the tower sites are running with inefficient technologies. Temperature rise in the shelter adversely affects the performance of the equipment's in telecom power system and temperature regulation is done by air conditioners. It is to be noted that, about 46% of the total energy consumption of an indoor telecom site is by air-conditioners. Majority of these cell sites use conventional AC air-conditioners, which consumes high energy. There is a huge potential to reduce this energy consumption and carbon print by replacing the conventional air conditioner with alternate cooling techniques. This paper briefly describes some of the energy efficient and low carbon footprint cooling techniques with their merits and demerits. Detailed comparison of these technologies in terms of their performance parameters are provided along with simulation results. Free cooling unit, Thermosiphon and wind chimney are found to be efficient when ambient temperature is less than shelter temperature; whereas combination of Phase changing materials and Geothermal cooling systems are preferred for sites having higher ambient temperatures. An indoor telecom power system is modeled in MATLAB Simulink to understand the dynamics of heat inside the shelter and to compare different air cooling technologies.