Our carbon footprint

Given Transpower’s pivotal role in enabling New Zealand's transition to a net zero carbon economy it is vital that we remain transparent and vigilant in the way we monitor, report and reduce our own carbon footprint. Every year we voluntarily measure and report our Greenhouse Gas (GHG) emissions and produce an annual GHG inventory report (in accordance with the International Greenhouse Gas Protocol and ISO 14046). We are working towards reporting for the External Reporting Board’s Aotearoa New Zealand Climate Standard 1 by the end of FY24. 

Our latest GHG Inventory Report

Our total gross Greenhouse Gas (GHG) emissions for the 2023 Financial Year (1 July 2022 – 30 June 2023) were approximately 162,883 tonnes of carbon dioxide equivalent (tCO2e). The graph below summarises the main sources of GHG emissions for the reporting period. For a detailed break down read our latest report here.

GHG inventory report


Total GHG emissions for FY23 were down 25% from FY22. The biggest decreases in emissions between the 2023 and 2022 reporting years were seen in Scope 2 emissions associated with transmission losses and electricity use, and in Scope 3 emissions associated with waste generation. In FY23, emissions from transmission losses totalled 111,323 tCO2e, reflecting an associated decrease in electricity grid emissions intensity driven by more renewable electricity generation, primarily hydro-generation, over the reporting year.


Scope 1 – 6,452 tCO2e, 4% of total emissions

Scope 1 emissions arise directly from our operations and include emissions from sulphur hexafluoride (SF6) and other gases and fuel usage, including in vehicles.

SF6 is used in some high voltage switchgear. Related emissions were 6,086 tCO2e in FY23, up 44% on FY22 (4,228 tCO2e reported in FY22).

Managing emissions from SF6 gases is an integral part of reducing our carbon footprint and Transpower’s Sustainability Strategy sets out several initiatives to manage these losses as part of our 2030 and 2050 emission reduction targets. Transpower has an SF6 management strategy to align our SF6 emissions with our 2030 emission reduction target and net zero by 2050 aspirations. Our SF6 management strategy commits us to more accurate SF6 handling, a proactive maintenance programme, and a phased equipment upgrade programme to replace lower voltage SF6 switchgear to drive our long-term SF6 emissions reductions.

Emissions from our vehicle fleet and purchased gas totalled 348 tCO2e in FY23, an increase of 13% reported over FY22. As outlined in the Sustainability Strategy, Transpower continues our long-running work programme to switch to electric vehicles where suitable options exist. In FY23, Transpower increased the number of battery and plug in hybrid vehicles to account for 92% of the passenger vehicle fleet, up from 80% of the passenger vehicle fleet in FY21 (and 15% in FY19).


Scope 2 – 111,572 tCO2e, 68% of total emissions

Our Scope 2 GHG emissions include electricity usage in buildings and substations, as well as transmission losses from the national grid network.

Emissions associated with electricity usage in Transpower buildings and substations were 249 tCO2e in FY23 (391 tCO2e in FY22). 

Transmission losses are a result of resistance caused by electricity passing through National Grid transmission lines and switchgear. The GHG emissions associated with transmission losses arise from the relative carbon intensity of the electricity generation mix. For FY23, these were estimated at 111,323 tCO2e (a decrease of 34% reported in FY22).

Transmission losses are set to fall as the electricity grid moves from being around 85% renewable in 2020, to a projected 96% renewable in 2025 and 98% in 2035 under current policy settings. Notwithstanding this, Transpower has a work programme under our Sustainability Strategy to better understand Transpower’s role in transmission losses and to prioritise our efforts in those areas under our control.


Scope 3 – 44,859 tCO2e, 28% of total emissions

Scope 3 GHG emissions include those associated with purchased goods and services, capital goods and construction and other supply chain activities such as business travel, waste and employee commuting. Transpower’s Scope 3 emissions totalled 44,859 tCO2e for FY23, an increase of 1% over emissions reported across FY22 (44,440 tCO2e).

As part of a long-running Sustainability Strategy work programme to better understand, report, and manage our Scope 3 GHG emissions, Transpower has continued to work closely with our wider supply chain through the 2023 Financial Year. FY23 saw a continued focus to move from an estimated financial expenditure-based approach to our Scope 3 emissions to a hybrid method – capturing both actual emissions data from our Service Providers and suppliers as well as some financial expenditure-based estimated data.


Relevant documents


Our emissions reduction target

In 2021 we set an ambitious goal to achieve a 60% reduction of our controllable Scope 1 and 2 GHG emissions by 2030, a target that excludes emissions arising from transmission losses. In FY22, we saw a 43% decrease in our controllable Scope 1 and 2 GHG emissions against our 2005 baseline. We are well on track to achieve a net zero grid by 2050.

Enabling the move towards an increasingly renewable electricity system for New Zealand is the biggest contribution Transpower can make to reducing our emissions. One challenge Transpower faces is that, as we enable the electrification of the economy by building new connection points and upgrading the national grid, our own carbon footprint is set to increase substantially. This is due to the likely rise in transmission losses – at least in the immediate term – as well as an increase in embodied carbon as part of the physical construction and upgrade of network infrastructure. It is important to note that any increase of our own carbon footprint will ultimately be offset by the net benefit of electrification to the country. Enabling electrification is the best way to reduce New Zealand’s overall emissions.

You can read more about our carbon footprint reduction initiatives in our Sustainability Strategy.


Greenhouse Gas Inventory Reports