Renewable Energy Factor

Description

The Renewable Energy Factor (REF) is a key performance indicator (KPI) that quantifies the share of renewable energy sources in the total energy consumption of a network element, site, or the entire network. It is introduced in 3GPP Release 19 as part of the broader initiative to improve energy efficiency and sustainability in mobile networks. The REF is specified in 3GPP TS 28.310 (Energy Efficiency Management) and TS 28.880 (Study on Energy Efficiency for 5G), which define how to measure, report, and use this factor for management and optimization.

In the context of 3GPP management architecture, the REF is an attribute that can be associated with a Managed Object (MO) representing a network function, a base station, or a site. It is calculated as the ratio of renewable energy consumed to the total energy consumed over a measurement period. Renewable energy sources include solar, wind, hydro, and other green sources, which may be supplied via the grid or on-site generation. The REF can be reported by the network element to the management system (e.g., via the O1 interface) and used by the operator to monitor sustainability, optimize energy usage, and report to regulators.

The REF is part of a suite of energy efficiency KPIs defined by 3GPP, such as Energy Efficiency (EE) and Energy Saving (ES). While EE focuses on the amount of data transmitted per unit of energy, REF focuses on the source of energy. Together, they provide a comprehensive view of the environmental impact of the network. The REF can be used in network planning, where sites with low REF might be candidates for renewable energy integration, and in dynamic operations, where traffic can be steered to sites with higher REF to reduce carbon footprint.

Key components of the REF include the measurement of renewable energy consumption, which may require additional metering or data from energy providers, and the calculation method, which must be standardized for consistent reporting. The REF can be expressed as a percentage or a fraction between 0 and 1. In 3GPP, the exact definition and reporting mechanisms are detailed in the specifications. The REF may also be used in conjunction with other factors like the Power Usage Effectiveness (PUE) for data centers.

The role of REF in the network is to enable operators to quantify and improve their use of renewable energy, aligning with global sustainability goals and regulatory requirements. It supports the transition to greener networks and helps operators make informed decisions about energy sourcing and infrastructure investments. As 5G and future networks expand, REF will be a critical metric for achieving carbon neutrality.

Purpose & Motivation

The Renewable Energy Factor (REF) was created to address the growing need for sustainability in mobile networks. As energy consumption of networks increases with the proliferation of 5G and beyond, operators face pressure from regulators, customers, and society to reduce their carbon footprint. Traditional energy efficiency metrics focused on reducing total energy consumption, but they did not account for the source of energy. The REF fills this gap by providing a standardized way to measure and report the proportion of renewable energy used, enabling operators to demonstrate their commitment to green energy and to optimize their energy mix.

Historically, 3GPP has defined energy efficiency KPIs in releases prior to Rel-19, such as the Energy Efficiency (EE) in TS 28.310. However, these did not include renewable energy aspects. With the global push towards net-zero emissions, 3GPP recognized the need for a metric that captures the environmental impact of energy sourcing. The REF was introduced in Rel-19 as part of the energy efficiency management framework, allowing operators to track and improve their use of renewables. It also supports the United Nations Sustainable Development Goals (SDGs) and the ITU's climate targets.

The REF solves the problem of lack of visibility into renewable energy usage at the network element level. Without it, operators could not accurately report their green energy usage or make data-driven decisions to increase it. The REF enables benchmarking across sites and vendors, and can be used in automated energy-saving features that prioritize renewable-powered sites. It also facilitates the integration of renewable energy sources into network operations, such as solar-powered base stations. By standardizing the REF, 3GPP ensures interoperability and a common language for sustainability reporting.