The UK has committed to a target of Net Zero emissions by 2050, with Scotland committing to 2045. To achieve these decarbonisation targets, the energy system must evolve from current fossil fuel dependency to low carbon alternatives. All four SGN SIU mainland networks currently utilise liquefied natural gas (LNG) sourced from the Isle of Grain LNG terminal in Kent, which is ultimately derived from fossil fuel sources at locations around the world and transported to the UK by bulk carriers. This feasibility study will cover three aspects of the potential to utilise a Scottish biomethane CNG alternative; these include the logistics chain between the biomethane production facility and the SIUs focusing on security of supply considerations, operational feasibility of utilising biomethane CNG and engineering and asset requirements to implement the biomethane solution with associated carbon savings.
Benefits
The study will focus on the need to de-carbonise all SGN gas networks including the SIU networks in line with government targets. The expected outcome is the provision of a feasibility study detailing the operational and logistical requirements to provide eighty percent of the two SIU networks’ annual energy requirements by Scottish produced biomethane CNG. The study will include all associated legislative safety, engineering governance and associated standards, along with consumer benefits and carbon savings
Learnings
Outcomes
Following this successful exercise, the scenarios generated through this study have shown that there is an opportunity to reduce operating transport costs, whilst reducing the carbon footprint of the gas that is transported in the network at the two site locations.
In addition to developing an optimised model as part of the potential next phase of planning, a recommendation would be to develop a phased a solution that defines an increasing uptake of biomethane CNG, based on an asset investment plan, maximising the use of each asset, and using the LNG infrastructure and supply chain as the flex.
The use of CNG trailers as a virtual pipeline is used globally and it is likely that bespoke designs can be created for each site. During the period of this feasibility study, it proved to be very difficult to get responses from these specialist manufacturers, however it is expected that these designs would decrease the footprint required on site and reduce installation costs, due to most of the equipment being pre-installed and located in its own housing.
Further investigation on options to supply BCNG or CNG from the existing network during weeks 1, 2, 51 and 52 would allow 80% of the two SIU networks’ annual energy requirements to be provided using a CNG option.
Lessons Learnt
There were many key questions answered particularly during Work Pack 1 (Logistics chain) that are valid for any potential future project, such as:
- Understanding the “real” capacity of CNG trailers and how this impacts the number of trailer deliveries required.
- Understanding that the capacity constraint, may be due to the biomethane production rate, or biomethane site planned outages.
Investigating a number of options during Work Packs 2 and 3 provided:
- A greater understanding of a no storage option compared to an on-site storage option.
- The addition of storage cylinders could be used to decrease the duration time that a trailer remains on-site. However, this option is only feasible if the trailer can be utilised elsewhere.
- Identifying that due to the modular nature of the assets required, capacity of the site could be scaled up if required and also modified from a no-storage option to a storage option with some forward planning design, or future site modifications.
- Although the project was focused on the 2 LNG SIU sites, the concept could be applied to any gas site and could be seen as a potential solution to mitigate against loss of supply.
