The footprint of gas transport
The transport of natural gas requires energy, for instance electricity and natural gas. We use this energy to keep the gas at pressure and transport it through the transport system and for the quality conversion of natural gas. The use of this energy causes both direct and indirect emissions. We also emit natural gas that is released during maintenance activities, from small fugitive leaks and from the use of equipment.
Gasunie reports emissions in accordance with the rules of the Greenhouse Gas Protocol (GHG Protocol), whereby these are categorised in 3 groups (scopes). For a detailed definition of the scopes and further specification of the emissions sources, see the annex Other data regarding safety, chain responsibility and the environment.
CO₂ equivalents according to the Greenhouse Gas Protocol
Gasunie has worked out programmes to achieve the targets for 2030 as well. These programmes are elaborated in annual plans.
|(in kilotonnes of CO2 equivalents)|
|1 (direct effect of own operations)||379||343||307||260||255|
|2 (indirect effect of energy bought in)||164||239||317||270||165|
|3 (other indirect effect, for instance of nitrogen bought in)||5||80||115||115||110|
|Total net scope 1 + 2 + 3||548||662||739||645||530|
|Greening bij Gos||78||247||358|
|Total gross scope 1 + 2 + 3||548||662||817||892||888|
In 2018, total CO2-equivalent emissions were lower than the emissions in 2017 (530 kilotonnes versus 645 kilotonnes). The reduction in CO2 equivalent emissions was mainly the result of the greening of our electricity consumption over the past three years thanks to the purchase of Guarantees of Origin (scopes 2 and 3). The gas consumption of our own installations also decreased compared to 2017 because of higher average temperatures and less foreign demand for H-gas (scope 1).
The results in relation to our natural gas consumption and electricity consumption are shown in the annex Other data regarding safety, chain responsibility and the environment.
Methane emissions and energy
Natural gas consists primarily of methane. Like carbon dioxide, methane is also a greenhouse gas. We calculate the contribution to the greenhouse gas effect in carbon dioxide equivalents, abbreviated as CO2 eq. For the purposes of our calculation, we assume that 1 kg of methane contributes 25 times as much to climate change as 1 kg of CO2. The Dutch government uses this factor, as well; for instance, in a recent report from the Dutch National Institute for Public Health and the Environment on emissions in the Netherlands (Greenhouse gas emissions in the Netherlands 1990-2016, National Inventory Report 2018). The factor is sometimes referred to as Global Warming Potential (GWP). We use 1990 as the base year, because we use the same starting points as the European Union (Europe 2020).
For Gasunie, the causes of methane emissions into the air are as follows:
- emissions caused when starting and stopping compressors;
- emissions from pneumatic equipment;
- fugitive leaks;
- emissions during work on the transport network.
Our methane emissions (scope 1) were 5,182 tonnes in 2018, somewhat higher than in 2017 (4,973 tonnes). This was because more gas was vented, so that gas that did not satisfy the specifications could be processed. The gas-fired compressors in Spijk and Wieringermeer were in operation for more hours because of the lower production from the Groningen field. More methane was emitted as a result. In Germany, market conditions caused transport routes for G-gas to change. This meant that one of the compressor stations was used more, resulting in higher emissions.
Approximately 4% of the human-caused methane emissions in the Netherlands can be attributed to the energy sector. One quarter of this 4% (1%) originates from Gasunie’s transport system. This transport system is used to transport approximately 40% of the Dutch energy requirements. The methane emissions caused by Gasunie represent approximately 0.01% of the total volume of natural gas transported in the Netherlands. Compared internationally, that is a low percentage.
How we manage our environmental impact
We are reducing our CO2-equivalent footprint in three ways:
- reducing natural gas emissions (methane emissions);
- more efficient energy use;
- increasing the sustainability of our energy usage by buying green certificates.
Our ambitions for reducing the carbon footprint are:
- 2020: reduce emissions that are a direct effect of our own operations by 20% compared to the reference year of 1990 (124 kilotonnes).
- 2030: by the end of 2030, reduce the emissions that are a direct effect of our own operations by 4% annually on average. The reduction will be compared each time to the emissions of the three previous years and will largely be achieved by reducing our methane emissions. In 2030, methane emissions will amount to a maximum of 50 kilotonnes (converted) of CO2 equivalents. This ambition ensures we remain a European front-runner in this area.
- 2050: our infrastructure will be fully CO2-neutral from 2050.
To guarantee that we take the environment into account in relevant business processes, we have set up our environmental management system in accordance with the international standard, ISO 14001. To ensure compliance with this standard, our environmental management system in the Netherlands is checked annually by an external auditing agency. In 2018, the external audit of the ISO 14001:2015 resulted in the certificate being renewed.
Measures to reduce the footprint
We want to further reduce our environmental footprint in the coming years, so we are taking measures to lower energy usage and prevent methane emissions:
1. Leak Detection And Repair (LDAR) programme
Some of the methane emissions are caused by small leaks at connections and appendages. It is a complex matter to track down these leaks because of the high number of stations and the length of the transport system.
We set up an LDAR programme to track down, quantify and repair leaks. In this context, we use the NEN-EN 15446 measuring method developed by the Environmental Protection Agency (EPA).
Gasunie uses LDAR at various Gasunie locations, such as: compressor stations, gas receiving stations, metering and regulating stations and high-pressure valve locations.
2. Emission reduction in making pipelines gas-free and in compression
Recompression: for some years, we have been using a mobile recompression unit which we use to recompress as much as possible of the gas that would otherwise have had to be vented, and transfer it to another pipeline. This reduces the amount of gas vented. In 2018, we recompressed 4.2 million m3(n) of natural gas, which means that we managed to prevent the emission of approximately 61 kilotonnes of CO2 equivalents. We estimate that we saved around € 1.0 million on natural gas costs in 2018 by deploying the mobile recompressor.
Making a pipeline gas-free using nitrogen: another way to avoid having to vent gas from a pipeline is to use nitrogen to displace the gas, thereby transferring it to a different pipeline. Recent trials in Gasunie’s gas transport network show that this is a very promising technique.
Flaring: in addition to recompression, we also use gas flaring. This is done using a mobile flaring installation. The environmental impact of flaring, whereby natural gas is burned off, is lower than if the gas is vented. Approximately 373,000 m3n of natural gas was flared in 2018. Compared to venting, this represents an environmental benefit of 4.8 kilotonnes of CO2 equivalents.
3. Regulating equipment that causes emissions
The decision was made in 2018 to stop renovating our metering and regulating stations. Consequently, some of the emission-causing regulating equipment will not be replaced with non-emitting equipment as expected. We are investigating the possibilities of an alternative programme for putting this emission-causing regulating equipment on air or operating it electrically.
4. Increasing the sustainability of our own electricity consumption
We are greening our electricity consumption by purchasing ‘Guarantees of Origin’. We purchased Guarantees of Origin from European wind farms in 2018. This purchase made approximately 60% of the electricity consumption sustainable. Gasunie Deutschland made 100% of its electricity consumption sustainable.
5. Emissions resulting from quality conversion
Since the government's decision to reduce the extraction level from the Groningen gas field, our use of quality conversion in the Netherlands rose from 5.7 billion m3 in 2013 to 28.9 billion m3 in 2018. As a consequence of this, nitrogen procurement once again increased in 2018 compared to 2017. Due to the decline in production from the Groningen gas field, an increasing amount of high-calorific gas is being bought in, which subsequently has to be converted to the right quality. This quality conversion takes place using self-produced nitrogen (scope 2) and nitrogen procured from third parties (scope 3).
The production of nitrogen requires energy (electricity). The CO2 equivalents resulting from the nitrogen procured are included in scope 3. In 2018 we bought in approximately 50.5% of electricity sustainably (approximately 111 kilotonnes of CO2 equivalents) for the production of nitrogen at third parties.
We endeavour to give as transparent as possible a picture of the emissions caused by Gasunie through communication on various levels. We do this by, among other things, reporting through electronic annual environmental reports, providing reports to the Dutch Emissions Authority (NEa) and publishing our annual reports.
In doing so, we look at all types of emissions that can occur in the gas infrastructure. Examples include fugitive leaks, emissions resulting from venting gas as the result of maintenance and the starting and stopping of gas compressors. The emissions from pneumatic components (parts of the gas transport system which emit gas during operation) are also included in the reports.
Contribution to the Sustainable Development Goals
We contribute to the Sustainable Development Goals based on our material theme of ‘Methane emissions’.
|We contribute to SDG:||We contribute to sub-goal|