White paper 5G network energy efficiency Introduction Energy consumption is a major contributor to network operating expenditure (OPEX) and also has an impact on CO2 emissions. In developing economies, almost a quarter of new cell sites will be beyond the power grid. The implementation of renewable energy and more energy-efficient equipment can bring significant benefits by helping operators to deal with unpredictable fuel prices. In mature markets, up to 15 percent of network OPEX is spent on energy. In developing markets, this can vary typically from approximately 15 percent up to 30 percent of network OPEX.