The emissions footprint of broadband in New Zealand

Client: Chorus

Which broadband technology has the lowest emissions footprint in New Zealand?

Emissions from network use are due to electricity consumption by the various equipment in the network, particularly customer premises equipment (CPE). International studies show that the fibre network has a lower carbon footprint than other broadband options, primarily due to energy savings.

We wanted to test this for the New Zealand context.

Using actual data from local networks, we find that for average access rates exceeding 50 Mbps, fibre has a lower per-user emissions footprint than all other fixed broadband alternatives in New Zealand. Compared to VDSL and HFC, GPON fibre can reduce emissions by 28-41% and 12-29%, respectively.

“What role can broadband technology play in supporting a low-emission future?

Chorus

In contrast to fixed wireless, GPON’s emissions reduction potential grows with increasing access speeds, as fixed wireless exhausts available bandwidth as access rates rise. Compared to FWA 4G, GPON’s per-user emissions footprint is 46-56 per cent lower at 50 Mbps, and 96% lower at 1 Gbps. Compared to FWA 5G, per-user emissions are 4-22% lower at 50 Mbps, and 91% lower at 1 Gbps.

At high average access rates (e.g. over 600 Mbps), XGS-PON provides an even greater emissions advantage than GPON due to more power-efficient equipment (Watts per user) outside customer premises.

Overall, we find that the contribution of CPE power use to total power consumption is particularly high for GPON and XGS-PON, indicating significant opportunities for emissions reductions in the fibre network through a switch to more energy-efficient customer premises equipment.

Full report


Our team included

  • Corina Comendant
  • Kieran Murray

Authors who contributed to this article

Corina Comendant