Carriers have been looking at energy efficiency for a few years now, but 5G will bring this to top of mind because it’s going to use more energy than 4G. Telcos spend on average 5% to 6% of their operating expenses, excluding depreciation and amortization, on energy costs, according to MTN Consulting. And this is expected to rise with the shift to 5G.
A typical 5G base station consumes up to twice or more the power of a 4G base station, writes MTN Consulting Chief Analyst Matt Walker in a new report entitled “Operators facing power cost crunch.” And energy costs can grow even more at higher frequencies, due to a need for more antennas and a denser layer of small cells. Edge compute facilities needed to support local processing and new internet of things (IoT) services will also add to overall network power usage.
Exact estimates differ by source, but MTN says the industry consensus is that 5G will double to triple energy consumption for mobile operators, once networks scale.
Warnings of more power consumption are coming from some Chinese operators that are leading the world in 5G deployments. In November 2019, China Mobile EVP Li Zhengmao said that its electricity costs were rising fast with 5G. China Mobile has tried using lower cost deployments of MIMO antennas, specifically 32T32R and sometimes 8T8R rather than 64T64R, according to MTN. However, Li says 5G base stations are carrying five times the traffic as when equipped with only 4G, pushing up power consumption. The carrier is seeking subsidies from the Chinese government to help with the increased energy usage.
According to Huawei data on RRU/BBU needs per site, the typical 5G site has power needs of over 11.5 kilowatts, up nearly 70% from a base station deploying a mix of 2G, 3G and 4G radios. 5G macro base stations may require several new, power-hungry components, including microwave or millimeter wave transceivers, field-programmable gate arrays (FPGAs), faster data converters, high-power/low-noise amplifiers and integrated MIMO antennas.
The increased power demands of a 5G site can create several problems:
- Insufficient AC power supply
- Insufficient battery capacity: more backup battery capacity is needed, yet traditional lead-acid batteries have low energy density and their capacities are difficult to expand.
- Unable to support high-power long-distance transmission: in 5G scenarios requiring high power supply to remote AAUs, the voltage drop required means that transmission distance is limited.
In addition to using more energy in the 5G RAN, carriers are also deploying edge computing resources to support such things as low-latency applications and IoT services. “Schneider Electric predicts that with 5G, the power distribution will require hundreds of thousands or even millions of micro data centers globally,” according to MTN. "Powering these sites will add to the telco utility bill and add a layer of complexity to network operations as edge power costs need to be minimized."
While the Chinese mobile operators may be a bit ahead of others in terms of 5G rollouts and lessons about energy efficiency, other operators are already thinking about utility bills, as well.
In March, AT&T COO John Stankey said that as part of an overall company effort to reduce costs, AT&T is looking at opportunities to take advantage of different architectures to lower energy costs.
“The bottom line is that, in an increasingly 5G world, telcos will face significant growth in their energy bills,” writes MTN Consulting. “To address this issue, telcos will need to take actions at the organizational, architectural and site levels.”