Hit by the suffocating cost of energy, which accounts for between 40 and 50 per cent of their Operating Expenditure (OPEX), telecom operators have turned to alternative energy sources to power their infrastructure, especially Base Transceiver Stations (BTS) and. Hit by the suffocating cost of energy, which accounts for between 40 and 50 per cent of their Operating Expenditure (OPEX), telecom operators have turned to alternative energy sources to power their infrastructure, especially Base Transceiver Stations (BTS) and. In 2008, the GSM Association (GSMA) gathered nearly 800 worldwide mobile operators to launch a plan for deploying renewable energy sources for 118,000 new and existing base stations in developing countries by 2012 to save 2. 5 billion litres of diesel and cut CO2 emission up to 6. 3 million tons per. This study evaluates the energy costs of hybrid systems with different generator schedules in powering base transceiver stations in Nigeria using the Hybrid Optimization Model for Electric Renewable (HOMER). It discusses how unreliable national power grid supply and dependence on expensive diesel generators has been a major challenge for telecommunications operations in.