Performance - environmental sustainability

Our environmental sustainability strategy, Our Contribution, focuses on the areas where we can make the greatest contribution to a more sustainable future.

With Our Contribution, we’re working to respond to global environmental and social challenges, minimize risk and continue to deliver the service our customers rely on.

We have identified three main themes that are most significant for our business and our stakeholders.
These are:

We have set ourselves challenging targets in each of these areas, which we are working towards so we can create a more sustainable future.

At National Grid we recognise and support the science that says our climate is changing due to the impact of human activities. We therefore measure the impact we have on the climate and have set ourselves goals to reduce our greenhouse gas emissions.

We independently assure our greenhouse gas emissions against the international standard ISO 14064-3 greenhouse gas assurance protocol.

We forecast that we will continue to significantly exceed (better) the 45% by 2020 reduction target. We expect the 2050 target (against our 1990 baseline) to be extremely challenging.

Scope 1 and 2 greenhouse gas emissions

Our Scope 1 and 2 greenhouse gas (GHG) emissions are reported in line with the WRI/WBCSD Greenhouse Gas Protocol Corporate Standard for all seven Kyoto gases and using the operational control approach for emissions accounting.

Our Scope 1 and 2 emission reduction targets exclude line losses, so we report our Scope 1 and 2 emissions both including and excluding this emission source.

These Scope 1 and 2 emissions are independently assured against the international standard ISO14064-3 Greenhouse Gas Assurance Protocol.

Our total Scope 1 and 2 emissions (excluding line losses) for 2016/17 were around 7.2 million tonnes of carbon dioxide equivalent (CO2e). This represents a 63% reduction on our 1990 base line. 

Our total Scope 1 and 2 emissions (including line losses) were around 10.3 million tonnes of CO2e (2015/16: 10.7 million tonnes).

 All figures include our UK Gas Distribution business.

Reduction in Scope 1 and 2 emissions against 1990 baseline (%)

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Carbon intensity (tonnes per £million)

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Breakdown of emissions 2016/17

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Scope 1 (bottom data) and 2 (top data) emissions (million tonnes CO2e) 

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Scope 3 greenhouse gas emissions

Our Scope 3 greenhouse gas emissions are reported in line with the WRI/WBCSD Greenhouse Gas Protocol Corporate Value Chain (Scope 3) Standard. We independently verify the emissions associated with our US sold product.

Our Scope 3 emissions for 2016/17 were around 33.9 million tonnes carbon dioxide equivalent (2015/16: 35.6 million tonnes), and consisted of:

  • around 2.6 million tonnes associated with the procurement of goods and services;
  • around 31.2 million tonnes associated with sold product (gas and electricity) in the US; and
  • other Scope 3 emissions of around 0.062 million tonnes, including business travel using 3rd party carriers and employee commuting.

A significant part of our investment in infrastructure is associated with modernising our networks and building connections to low carbon sources of energy. As a consequence, we expect our Scope 3 emissions to potentially go up due to this increase in construction in the short term as we play our part in decarbonising the economy. We then anticipate a reduction in our reported transmission and distribution losses as the grid average carbon intensity decreases. 

In the US, our reported emissions associated with customers may rise as our customer base increases. However, our energy efficiency programmes are making a real difference in helping our customers reduce their energy use. The American Council for an Energy-Efficient Economy (ACEEE) scored all three states that we operate in among the top 5 for energy efficiency, with Massachusetts ranked at number one. 

We have backed the Environmental Protection Agency’s (EPA) proposed Carbon Pollution Standards for New and Existing Plants (known as the Clean Power Plan). As we and other organisations have requested, the EPA’s final plan provides states with compliance flexibility and makes sure that early emissions reductions via investment in renewable resources and energy efficient strategies are counted. With our partners Smartpower we received the EPA Clean Air Excellence Award 2016 for Education /Outreach.

In the US our Connect21 strategy aims to advance the country’s natural gas and electricity infrastructure beyond its 20th century limitations, and create a more customer-centric, resilient, agile, efficient and environmentally sound energy network. We have committed to work towards a decarbonised energy network by 2050. 

In the UK the biggest contribution we can make to the environment is by connecting low carbon and renewable energy to our network. We are also working hard to reduce our own carbon footprint. We have recently introduced a carbon calculator into our tender process. This is good news for the environment and for consumers because it reduces our impact on the environment and reduces our costs.

 All figures include our UK Gas Distribution business.

Scope 3 emissions customer use (bottom data) supply chain use (top data) (million tonnes CO2e)

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Scope 3 emissions other (million tonnes CO2e)

23 Scope 3 emmissions other (million tonnes CO2e).png
Carbon intensity

We measure our carbon intensity. For 2016/17,excluding line losses, this was 424 tonnes carbon dioxide equivalent per £ million of revenue compared with 496 tonnes in 2014/15.

Climate adaptation

Climate adaptation

In the UK in 2016 we provided updated reports to the Department for Environment, Food and Rural Affairs (Defra) on our approach to Climate Change Adaptation. 

In their feedback Defra acknowledged that we incorporate a range of hazards and assess, as well as considering the interaction between weather hazards and geo-hazards. Defra also noted that including climate change risks as part of our wider risk assessment process is a positive approach.

Our assessment process uses the government's latest climate change scenarios to test the resilience of our networks to a range of future conditions. The ongoing monitoring and appropriate mitigation of the risks from a changing climate is built into our day-to-day business risk management processes.

We have made progress since the first round of reporting, which began in 2010. An example of this would be our flood mitigation work for tidal and fluvial flood risk; via a prioritised investment programme we have exponentially reduced the level of risk. 

Climate adaptation reporting second round: National Grid 

In the US, we continue to work with state task forces, and the primary focus of our adaptation work has been on flood risk assessment and mitigation requirements for our electricity assets.

Sulphur hexafluoride 

Sulphur hexafluoride is an extremely effective electrical insulator and has significant advantages over alternative materials. It is non-flammable, a critical requirement in the high-voltage applications we use it, and because of its effectiveness takes up less volume than an equivalent insulating volume of an oil alternative.

Sulphur hexafluoride (SF6) is a greenhouse gas – one tonne is equivalent to approximately 23,900 tonnes of carbon dioxide. In 2016/17, leakage accounted for around 5% of our total scope 1 and 2 greenhouse gas emissions (excluding line losses).

Reported gas loss for our combined UK and US operations, as an absolute amount (percentage of inventory) was 14.8 tonnes (1.7%) in 2016/17, compared with 12.0 tonnes (1.3%) in 2015/16.

Sulphur hexafluoride losses (tonnes) percentage of inventory

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Sulphur hexafluoride inventory total (tonnes) 

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Energy use

Our energy use is dominated by gas and oil used by our US generation facilities.

Our generation facilities on Long Island used approximately 14.8 million MWh of natural gas and 1 million MWh of fuel oil during 2016/17. 

Our non-generation energy is used mainly by our gas-fuelled compressors on our UK Gas Transmission network and the Isle of Grain LNG import terminal.

In 2016/17 we used approximately 2.5 million MWh of gas and 0.7 million MWH of electricity in our non-generation activities.

Energy use: electricity (top data), gas (bottom data) (million MWh)

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Fuel used for transport 

During 2016/17, we used some 49 million litres (2015/16: 51.5 million litres) of petrol and diesel for our commercial fleet, company cars and private cars used for business travel.

Fuel used by transport (million litres)

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Water use

The majority of water used by our Company is used for cooling at our generation facilities in the US and electricity cables in the UK. This water is returned to source after use, so equates to zero consumption.

Water consumed 
During 2016/17, we consumed approximately 1.4 million cubic metres (mcm) of fresh water for both operational and non-operational purposes across our operations, compared with 1.5 mcm in 2015/16. This equates to some 82.4 cubic metres per £ million of revenue (2015/16: 98 cubic metres per £ million of revenue).

Cooling water
During 2016/17, we extracted and returned to source around 1.266 mcm of sea water (2015/16: 1,330 mcm) used as cooling water at our US generation facilities

Extracted water (for data) mains water (bottom data) (million cubic metres)

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Water used for cooling (million cubic metres) 

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ISO 14001

We have continued to implement environmental management systems certified to the international standard ISO 14001. 

100% of our material operations are covered by ISO 14001 environmental management systems.

At 31 March 2017, approximately 93% of our employees worked to certified ISO 14001 environmental management systems, the same as last year. The remaining 7% are mainly office based employees in the US.

ISO 14001 employee coverage (%)

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Environmental incidents

In the UK we have had five significant environmental incidents comprising one vehicle diesel leak, one fluid filled cable oil loss, two gas venting incidents and failure of a circuit breaker resulting in SF6 loss. One of these incidents was the responsibility of a third party. Also there are nine ongoing SF6 leakages from electrical transmission equipment for which we are awaiting circuit outages to enable us to make the necessary repairs.

In the US, we have had three significant environmental releases. These included a failure of an SF6-containing breaker, as oil release from a substation transformer, and a release of natural gas and natural gas liquids from a pipeline. There was also one significant legal notice for wetlands sedimentation due to a water main break.

Our targets are zero significant environmental incidents.

Significant environmental incidents - own fault

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Significant environmental incidents - third party

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Treatment of waste

During 2016/17, we generated some 0.25 million tonnes of waste, a considerable reduction when compared with 0.6 million tonnes the previous year. This equates to some 14.72 tonnes per £million of revenue. 

Of the 0.25 million tonnes of waste, around 94% was recycled, down 1% compared with the previous year.

A large, but variable, contributor to our total and recycled waste is associated with remediation of historically contaminated manufactured gas plant sites. Depending on the level of remediation activity, as well as the type of remediation, there can be large year-to-year changes in our total waste and, to a lesser extent, the percentage of recycled waste. 

Waste generated (million tonnes)

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Waste reused and recycled (%) 

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NOx & SOx emissions

Our material emissions of NOx are from our generating facilities in the US and compressors installed on the gas transmission network in the UK. Our generating facilities in the US are our only material source of SOx.

In 2016/17, we emitted around 2,766 tonnes of NOx and 2,102 tonnes of SOx, compared with 2,306 and 2,414 tonnes respectively in 2015/16.

NOx emissions (tonnes)

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SOx emissions (tonnes)

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Customer energy efficiency

In the US, our energy efficiency programmes are making a real difference in helping our customers reduce their energy use. The American Council for an Energy-Efficient Economy (ACEEE) scored all three states we operate in among the top 5 for energy efficiency. 

Due to reporting requirements, our US energy efficiency data is on a calendar year basis and it is generally not available until October the year after. So the data here is for the year ending December 2016. 

National Grid offers many electricity and natural gas energy-efficiency programmes for residential and business customers. For residential customers, the programmes offer various incentives and assistance to make homes more energy efficient through lighting, appliances, high efficiency heating equipment and water heaters, boiler controls, and insulating and sealing measures. For business customers, the Company’s electricity and natural gas energy efficiency programmes can help improve efficiency at existing or new facilities by lowering operation and maintenance costs through efficient lighting and controls, heating systems, heating, ventilation and air conditioning (HVAC), windows and insulation instalments, and by participating in other industry-specific efficiency installations and programmes.

During the 2016 calendar year participation in National Grid’s gas energy-efficiency programmes had a 10% increase over 2015, with just under one million participants. In 2016 there were also 3.7 million participants in the Company’s electric energy-efficiency programmes, which is an 8% increase from 2015; combined this resulted in 4.7 million participants in our gas and electric programmes.

Through participation in these programmes during 2016, customers saved over 29 million annual therms of gas and more than 1.2 million annual megawatt-hours of electricity savings. These equate to 170,905 tonnes and 468,042 tonnes carbon dioxide equivalent (CO2e) respectively, based on state-specific conversion factors.

More information on our US energy efficiency programmes can be found via the energy service and regions links on our US website.

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