The footprint of gas transport
Natural gas consists primarily of methane, a greenhouse gas like CO2, but stronger. The Global Warming Potential (GWP) is a measure for the contribution to the greenhouse gas effect with respect to CO2. In our reports, we use a Global Warming Potential (GWP) of 25 for our calculations, as does the Dutch government. That means that 1 kilogramme of methane’s impact on climate change is 25 times that of CO2. The IPCC (Intergovernmental Panel on Climate Change) regularly updates the GWP based on the latest scientific insights.
According to the Dutch Compendium for the Living environment (Compendium voor de Leefomgeving), the general picture is that approximately 4% of the human-caused methane emissions in the Netherlands can be attributed to the energy sector. The Compendium also says that one quarter of that 4% (approximately 1% of all the methane emissions in the Netherlands, therefore) can be attributed to emissions in the Gasunie transport system (which is used to deliver over 40% of all the energy used in the Netherlands to its users). The methane emissions caused by Gasunie represent approximately 0.01% of the gas transport in the Netherlands. Compared internationally, that is a low percentage.
Natural gas is also more favourable than other fossil fuels when it comes to CO2 emissions. A study by the International Energy Agency (IEA) shows that the CO2 emissions (per unit of energy produced) from gas are approximately 40% lower than from coal and approximately 20% lower than from oil.
The transport of natural gas requires energy, for instance the electricity and natural gas we use to keep the gas under pressure and transport it through the transport system. Energy is also required for the quality conversion of natural gas.
How we manage our environmental impact
We are reducing our CO2-equivalent footprint in three ways — by reducing natural gas emissions (methane emissions), through more efficient energy use and by 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 internationally accepted standard, ISO 14001. To ensure compliance with this standard, our management system is checked annually by an external auditing agency. In 2017, the recertification of the ISO 14001:2015 led to a positive result.
We report in accordance with the standard of the Greenhouse Gas Protocol (GHG Protocol). This protocol for greenhouse gases distinguishes various categories (scopes), based on where the emissions are generated (emissions source). For a detailed definition of the scopes and further specification of the emissions source, see the annex ‘Other data regarding safety, chain responsibility and the environment’.
CO₂ equivalents according to the Greenhouse Gas Protocol
Up to the end of 2017, we achieved an absolute reduction of 131 kilotonnes of CO2 equivalents. As such, we achieved our environmental target for 2020 in 2017 already. New programmes are currently being worked out to achieve the targets for 2030.
|(in kilotonnes of CO2 equivalents)|
|1 (direct effect of own operations)||575||379||343||307||260|
|2 (indirect effect of energy bought in)||172||164||239||317||270|
|3 (other indirect effect, for instance of nitrogen bought in)||4||5||80||115||115|
In 2017, total CO2 equivalent emissions were lower than the emissions in 2016 (645 kilotonnes versus 739 kilotonnes). The CO2 equivalent emissions caused by our own operations (scope 1 of the Green House Gas Protocol) are mainly due to a reduction in natural gas emissions over the past several years and a reduction in CO2 equivalents because of the purchase of Guarantees of Origin for electricity (scopes 2 and 3).
Methane emissions and energy
Our methane emissions in 2017 (scope 1) were 4,973 tonnes lower than in 2016 (7,252 tonnes). This decrease is mainly due to the fact that we repaired many small leaks at various installations over the past year as part of the Leak Detection and Repair (LDAR) programme. Less gas was also vented in 2017.
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’.
Measures to reduce the footprint
We will be realising a number of measures in the coming years to reduce our footprint. This will ensure that we save energy and limit our methane emissions.
1. Leak Detection And Repair (LDAR) programme
Gasunie deals with ‘uncontrolled’ methane emissions, for instance as the result of ‘fugitive leaks’ from connections and appendages. It is a complex task to identify these emissions in our transport system, which involves approximately 15,000 kilometres of pipelines in the Netherlands and Germany and also includes compressor stations, metering and regulating stations and gas receiving stations.
The LDAR programme was set up to track down, quantify and repair leaks. A measuring method developed by the Environmental Protection Agency (EPA) is used to do this. This measuring method is implemented at various Gasunie locations to determine the methane emissions.
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 2017, we recompressed 4.7 million m3(n) of natural gas, which means that we managed to prevent the emission of approximately 69 kilotonnes of CO2 equivalents. We estimate that we saved nearly € 1.2 million on natural gas costs in 2017 by deploying the mobile recompressor.
Gas flaring: in addition to recompression, we also use gas flaring. This is done using a mobile flaring installation, for instance. The environmental impact of flaring, whereby natural gas is burned off, is lower than if the gas is vented. Approximately 372,000 m3n of natural gas was flared in 2017. Compared to venting, this represents an environmental benefit of 4.8 kilotonnes of CO2 equivalents.
Nitrogen displacement: in 2017, an experiment was carried out to prevent future emissions in the process of making pipeline segments free of natural gas. In this experiment, nitrogen was used to displace natural gas in a pipeline. By closing valves at the right moment, a partition is created between the natural gas and the nitrogen. This brings the natural gas to a segment of the pipeline that is not to be made gas-free, thus avoiding the need to vent gas.
3. Regulating equipment that causes emissions
The reduction of methane emissions by putting emission-causing regulating equipment on air or operating it electrically.
4. Increasing the sustainability of our own electricity consumption
Gasunie in the Netherlands purchased Guarantees of Origin from European wind farms to increase the sustainability of our electricity consumption in 2017. This purchase made approximately 40% 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 rose from 5.7 billion m3 in 2013 to 25.8 billion m3 in 2017. As a consequence of this, nitrogen procurement once again increased in 2017 compared to 2016. 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 hydrogen and nitrogen bought in from third parties. The production of nitrogen requires energy (electricity). The CO2 equivalents resulting from the nitrogen bought in are included in scope 3. In 2017 we bought in approximately 40% of electricity sustainably (approximately 67 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 this context, we look at all types of emissions that can occur in the gas infrastructure, such as ‘fugitive emissions’, emissions from gas venting due to maintenance to our gas transport system or the starting and stopping of gas compressors, but also the emissions from pneumatic components (parts of the gas transport system that emit gas while functioning).