5G Networks Can Reduce Carbon Emissions Significantly with Sufficient Investments in Renewable Energy

Fighting climate change and building a green future demands bold actions from mobile operators, and many across the world have created targets aligned with global warming scenarios. Telefónica created the target of reaching 100% renewable by 2030 and net zero by 2025 in main operations, whereas Orange and Vodafone have planned to reach net zero by 2040. In 2018, T-Mobile became the only operator to set an ambitious target of sourcing 100% of its electricity from renewable sources by the end of 2021. On January 31, 2022, T-Mobile announced that it has accomplished the mission of achieving 100% renewable energy, through a combination of renewable energy and energy efficiency investments. Moving forward, T-Mobile will expand its renewable energy portfolio to match future electricity consumption and announce new commitments to further decarbonize its business in late 2022.

Worldwide renewable energy generation capacity has increased by 3.7-fold to 2799 GW in 2020, up from 754 GW in 2000. Solar photovoltaic (PV) was the largest contributor among the 260 GWs of newly added renewable energy generation capacity in 2020. With improved technology, experience, competitive supply chains, and economies of scale, the cost of electricity from renewable energy sources have declined sharply in the past decade.

Operators are expressing more interest in renewable energy due to the large decrease in cost since deploying renewable energy sources is essential in order to meet emission targets. For example, T-Mobile has made nineteen retail agreements, eight virtual power agreements, one Green Direct program, and unbundled Renewable Energy Certificates to support projects across the US. The nine large solar and wind projects from the virtual power agreements and Green Direct program alone provide T-Mobile with an annual clean energy of 3.4 million MWh, sufficient to cover electricity across 313,000 homes per year. Aside from investing in renewable projects, T-Mobile also focuses on energy conservation, including optimizing air management to cool equipment at cell sites, installing energy-efficient radio equipment, upgrading electrical and mechanical systems in data centers, and switching to energy star certified LED lighting in retail stores. The LED lighting is 75% more efficient and enables an annual saving of 2255 tons of carbon emissions through an energy reduction of 5.5 million kWh. Telefónica also made significant savings by switching to renewable energy. In 2020, a total of nearly 5000 GWh of electricity was obtained from renewable energy sources and resulted in a carbon emission reduction of 911,070 tons, emphasizing that renewable energy is the key to achieving decarbonization and reaching carbon emission goals in absolute terms. It was also highlighted that renewable energy investments project a potential saving of 25% on O&M (Operation and Maintenance) cost by 2030.

Renewable energy is a supplement to grid power owing to their intermittency nature. The investment cost may have fallen but it could still create significant burden for operators with limited budget. To maximize the total cost of investment and show support to fight climate change, network operators who plan to deploy renewable energy at cell sites should start with regions that promote the use of renewable energy sources and have well-established energy policy. In this way, operators maybe eligible to apply for grant or receive tax reduction to help with the initial investment. Renewable energy is usually coupled with storage to optimize its use, which could bring additional benefits. Energy supply is relatively static but energy demand tends to fluctuate over the day, making the cost of electricity during peak hours a lot higher than off-peak hours. Operators can save money by buying more energy when price is low to be stored and used later and make additional revenue by trading their surplus energy at peak times.

Besides investment in renewable energy, operators need to plan their network with precision. 5G is still primarily deployed on existing 4G sites, with a crowded network being less efficient and costly. Therefore, operators need to modernize their network by replacing the legacy equipment with more energy efficient equipment to enhance performance and reduce power consumption and cost. Equipment vendors already offer solutions for radio site modernization and have proven to be cost effective. For instance, Orange Spain has deployed ZTE’s Unisite+ solution, and this solution helped to reduce the number of radio units by 60% and energy consumption by 30%. It has been estimated that the annual energy cost saving is 1200 Euro for an average site. On top of new radio, operators should deploy the energy-saving software which is available from a number of vendors (Ericsson, Nokia, ZTE, Samsung, Huawei, etc.), as they are capable to reduce energy consumption by an extra 20% on average without affecting network quality. With this software widely deployed, it can collect more data which can then be used to better train the algorithm and leads to higher accuracy. Another area to focus is to reduce the power used for cooling. Liquid cooling has proven to reduce site energy expenses by 30% and carbon emission by 80% from deployment in commercial networks. Moreover, liquid cooling does not require maintenance, offering additional saving for operators.