EPRI research investigates potential radiofrequency exposure of workers and the public
Successful and abundant TV advertising has guaranteed that the average person can recite the purported benefits of 5G mobile networks. Commercials featuring both regular people and celebrities like Saturday Night Live’s Kate McKinnon and singers Dolly Parton and Miley Cyrus extol how much 5G accelerates the speed of video downloads and minimizes the delay (also known as latency) that occurs after requesting data from a network.
The very name “5G” is meant to convey progress. Indeed, 5G refers to the fifth-generation technology standard for cellular networks—the successor of 3G and 4G. Given the ubiquity of smartphones, it’s hardly surprising that wireless network providers are eager to promote the benefits of 5G. For a wide range of reasons, though, the utility industry should also care about the rapid deployment of 5G antennas and other infrastructure.
At one level, a secure and modernized grid depends on robust communications. For example, the grid is integrating larger and larger amounts of distributed energy resources (DER) like solar photovoltaics, wind, and energy storage. As DER deployments accelerate, communications become more critical as a tool to connect utilities, customers, and marketplaces in ways that drive decarbonization and enhance grid reliability and resilience.
5G technology also has the potential to improve the future electric grid by advancing everything from augmented reality to automated drones and vehicles. Some utilities are already exploring implementing private 5G networks to enhance security against cyberattacks and to aid remote monitoring and control of grid assets, such as substations and solar power plants.
Concerns About Health Impacts of 5G
Even if utilities haven’t fully strategized how 5G can aid grid modernization and security, they must consider its deployment. One reason: the infrastructure required to support 5G will often be installed on existing grid assets. “Utilities should be thinking about this, and some definitely are, because some have been mandated to install antennas on transmission towers and distribution poles,” said Phung Tran, an EPRI program manager.
Utilities also need to be aware of potential customer and worker exposure to radiofrequency (RF) electromagnetic fields emitted by newly installed 5G equipment and the mobile devices it supports. Concerns over potential health and environmental effects of RF exposure have triggered calls for bans and moratoriums on 5G rollouts as well as debates about the science behind some of the concerns.
Exposure limits for workers and the general public have been set by the International Commission for Non-Ionizing Radiation Protection, the Federal Communications Commission, and IEEE. Compliance with these limits depends in part on the relative locations of the individual and the transmitter.
To better understand typical exposures for workers and those using devices that receive data via 5G networks, EPRI recently conducted a pilot study that combined real-world measurements from 5G base stations in Belgium and developed a methodology for measuring exposures. This research, released in 2022 (5G Exposure Measurement Pilot Study, EPRI report 3002021620), sought to better understand the typical user and worker exposures near small cell 5G New Radio base stations. These are low-power base stations installed in locations where utility workers and smartphone and other device users could come in close contact with them while they are operating.
Big Differences with 5G and Research Results
It’s important to understand just how different 5G is from previous 2G, 3G, and 4G systems. One big difference is that, though most of the 5G being installed will be implemented in the same frequency band as the previous systems, some 5G applications may be implemented in the higher-frequency millimeter wave RF band. Less is known about RF exposure levels for millimeter waves, though basic physics has shown that they don’t penetrate human skin as much as lower-frequency waves.
Another important difference is that 5G equipment typically provides coverage to smaller geographic areas than previous technologies. As a result, 5G infrastructure can be installed at a lower height on utility poles, and the base stations don’t need as much power to transmit data to users. In general, this means that RF exposure should be less from these lower-power base stations than from older networks.
But there are some nuances that make accurate measurements of exposure challenging. For example, some 5G antennas have what are known as beamforming capabilities. “In legacy networks, the base station doesn’t ‘know’ where the user is located: it broadcasts uniformly over the expected coverage area,” Tran said. Beamforming capabilities, by contrast, allow power to be directed depending on where a user is located. “This ability for 5G antennas to direct power to facilitate communication makes it hard to assess exposure. It’s not as simple as before,” Tran said.
To account for those differences, EPRI’s research took a different approach than past efforts to measure exposure. Instead of assuming exposure to a uniformly distributed RF field, this study included information about the location of users and non-users of the system. It encompassed a wide range of scenarios, including active users and non-users at different locations and different numbers of active users.
The measurements also accounted for how far someone was from a base station, how high the antennas were installed, and what direction the beam was pointing. “We went through and identified user scenarios and types of users to make measurements more relevant than just maximum theoretical exposures,” Tran said. “That is more representative than what has been done in the past.”
EPRI found that all exposure levels for workers and the public for the two 5G base stations studied were well within established limits. Another finding: 5G antennas with beamforming capabilities produce lower RF exposures.
However, there are limits to these findings and more work to be done. “This is good news for 5G, but we have to caution people that the two systems we took measurements from operate at a lower frequency range that overlaps with an existing 4G system and not in the millimeter wave range,” Tran said. “We need to do a separate study to look at the higher frequency range, but we can’t do that until we get access to these systems.”
Even before that research can be initiated, however, there are ways for utilities to begin using these results. In particular, the findings of this study can help inform how utilities communicate with their employees and provide RF safety awareness training. They can also help answer customers’ questions about potential RF exposures from utility-involved 5G deployments.
EPRI Technical Expert:
Phung Tran
For more information, contact techexpert@eprijournal.com.
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