Gas Distribution Network companies are at the centre of the drive to decarbonise the national gas grid paving the way for the Energy Systems Transition to low/zero carbon whilst maintaining the level of customer service and efficiency levels. Fundamental to this strategy is replacing ‘natural gas’ with zero carbon gases via the use of green Hydrogen and to a lesser extent biogas.
Hydrogen is gaining traction in the UK:
Hydrogen is a non-toxic colourless gas and is the most abundant gas in the Universe, the gas is odourless, tasteless and highly combustible. There are no natural hydrogen deposits on earth and the gas is extracted from other compounds by a chemical reforming process or electrolysis of water which splits the two atoms of hydrogen from oxygen in a clean process providing the power is derived from renewable energy.
How is it produced?
To date, Hydrogen has been derived from fossil fuels using a natural gas ‘reforming process’ which emits CO2 as a by-product, this is called gray hydrogen. This gas can be brought to net zero carbon if the CO2 is ‘captured and stored’ this is defined as blue Hydrogen.
Both blue and green Hydrogen are classed as net zero carbon. The production of blue Hydrogen requires the application of large-scale carbon capture and storage which requires substantial investment, therefore green Hydrogen manufactured using renewable energy is the favoured source. Moreover, using renewable energy to create effectively an energy store in Hydrogen can go some way to help solve the problem of intermittency of generation that plagues wind and solar power,
The case for decarbonising the National Gas grid
The volume of carbon that could be displaced is vast, currently in the UK CO2 emissions for the burning of natural gas is c. 180 million tonnes, 40% of the UK total.
Based on Hydrogen fully replacing natural gas in the heating of buildings, industry and power generation, and replacing fossil fuels in surface transport and shipping, it is conservatively estimated this would result in emissions savings of between 30m and 105 million tonnes CO2 p.a. – this is a celar “big ticket” item to deliver the 2050 goal.
Hydrogen can also help accommodate the growth of renewable electricity, with wind and solar power being used to produce hydrogen. This green Hydrogen then being used to produce power via gas fired generation plants during periods when wind and solar generation have low output or stored for use in the gas networks.
Therefore on the face of it a transition to Hydrogen is a logical development but the application of this super gas is not without risk and management challenges:
Impact on the physical gas network assets
But replacing natural gas with hydrogen the network has to operate under somewhat higher pressures and gas flows in addition to the swap out of the Nations’ traditional gas boilers. On the pipeline front, the higher pressures and flow may lead to an increase in leakage risks, particularly in high-pressure pipes. In some legacy steel pipes risks from Hydrogen embrittlement is a major factor.
This swap to the use of Hydrogen therefore has to be accompanied by a significant upgrade of the network monitoring and management tools.
The requirement for real time accurate operational data
Current Network management decision models have been developed over many years and while being very reliable are based on the use of natural gas, such models are therefore based on historical data and fairly high level but backed up by substantial operational experience. However the information tends not to be real time and means Operational Management groups are largely reactive in terms of network management which adds significant costs through inefficiencies.
The transition to Hydrogen changes the network management demands requiring real time and accurate data from the network itself in terms of pressure, temperature, flow, gas composition and other essential control data.
Energy Transition to the wider use of Hydrogen inevitably adds complexity as Gas Network Operators need to effectively manage and operate both natural gas and an expanding use of Hydrogen on the network. The GNO’s are therefore turning to the use of real-time operational data systems with much higher levels of granularity using a range of new sensors deployed to monitor the basic network assets, effectively providing an IoT (Internet of Things) with data that will lead to higher levels of data analytics through the adoption of machine learning and artificial intelligence.
The transition to hydrogen in the UK gas networks is critical to achieving the net zero 2050 UK goal but it comes with challenges that need to be navigated by Gas Distribution Network companies who need to ensure that they are transparent and fair in delivering change for their customers. These companies are embracing this transition and the upgrade network management involved which is opening whole new areas of innovation and business opportunity.