Our carbon footprint

Here we break down our greenhouse gas emissions for financial year 2020/21 (FY21) and discuss what we are doing to record, manage and reduce them.

We also produce an annual unknown file and are adopting Task Force on Climate-related Financial Disclosures (TCFD) standards. See our three-year TCFD adoption plan.

FY21 emissions

Transpower’s total greenhouse gas emissions for FY21 reporting period are estimated at 265,996 tCO2-e, an increase of 1,050 tCO2-e (<1%) from that reported for FY20.  

The biggest decrease in emissions between the 2021 and 2020 reporting years was seen in Scope 3: purchased goods and services, and capital goods and construction. This decrease has arisen through an improvement from an estimated financial expenditure-based approach for these categories in FY20 to a more accurate hybrid method of capturing actual emissions data from suppliers and Service Providers. This has been combined with financial-expenditure-based estimated data for FY21.

Scope 1 – 5,300 tCO2e, <3% 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 4,928 tCO2-e in FY21 (5,037 tCO2-e in FY20), down 2%.

Transpower recognises that managing emissions of SF6 is an integral part of reducing its carbon footprint. Transpower’s Sustainability Strategy sets out several key initiatives to limit SFfugitive losses to <0.8% of installed nameplate capacity of the switchgear. Transpower also has a work programme underway to develop a long-term SFreduction plan. This includes proactive seal replacements and SFequipment refurbishments, as well as a programme to implement practices to reduce SFemissions that occur when handling the gas during equipment installation, maintenance and disposal. Over the medium to long term, we seek to systematically reduce our use of SF6 dependent equipment by continuing to work with our suppliers to monitor the market for SF6-free equipment.

Emissions from our vehicle fleet totalled 371 tCO2-e in FY21, an increase of 5% over FY20. As outlined in the Sustainability Strategy, Transpower continues its long-running work programme to switch to electric vehicles where suitable options exist. In FY21, Transpower increased the number of battery and plug in hybrid vehicles to account for 80% of its passenger vehicle fleet, up from 50% in FY20 (and 15% in FY19). Transpower is aiming to convert 100% of passenger vehicles to battery or plug in hybrids by June 2022, as well as explore opportunities to decarbonise its 4x4 vehicle fleet.   

Scope 2 – 214,177 tCO2e, <81% of total emissions

Indirect, Scope 2, GHG emissions include electricity usage in buildings and substations, as well as transmissions losses

Emissions associated with electricity usage in Transpower buildings and substations rose to 808 tCO2-e, an 80% increase from FY20, despite usage decreasing. This rise is attributed to the increased carbon intensity of the electricity generation mix over the reporting period. Transpower is consistently investigating energy efficiency opportunities and has a building energy efficiency plan in place. It is are also looking at opportunities to develop local, small scale, renewable generation and battery systems at its sites. 

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 FY21, these totalled an estimated  213,369 tCO2-e (an increase of 26% from FY20).

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 its Sustainability Strategy seeking to better understand Transpower’s role in transmission losses and to prioritise its efforts in those areas under its control.

Scope 3 – 46,519 tCO2e, 17% of total emissions

Scope 3, indirect, 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 46,519 tCO2-e for FY21, a decrease of 48% over FY20.

Transpower is committed to working across its wider supply chain to better understand, report and manage Scope 3 GHG emissions. To address this challenge, Transpower has initiated several work programmes under its Sustainability Strategy focused on improving data capture and reducing associated Scope 3 emissions with its key Service Providers and suppliers.

Transpower’s emissions reduction target

Enabling the move towards an increasingly renewable electricity system is the biggest contribution Transpower can make to reducing its emissions. Transpower will continue to investigate opportunities for the reduction of transmission losses for components under its control. However, Transpower foresees that associated emissions will continue to decrease following an increase in renewable generation. It has also commenced a comprehensive programme to investigate how it can reduce Scope 3 supply chain emissions over the coming years. You can read more about this in Transpower’s Sustainability Strategy.

To date, Transpower’s target has been to reduce emissions directly under its control. This includes fugitive SF6 and other gases, fuel use (including vehicle combustion), and energy usage in its buildings and substations. Against a 2006 baseline of 8,710 tCO2-e, the goal is to cut these emissions by 60% by 2030. In FY21, in-scope controllable emissions totalled 6,108 tCO2-e, a 30% reduction from base levels.


Greenhouse Gas Inventory Reports

2020/21 [ pdf 1.07 MB ]

2019/20 [ pdf 740.77 KB ] 

2018/19 [ pdf 591.98 KB ]

2017/18 [ pdf 850.34 KB ]


2015/16 [ pdf 944.24 KB ]