GFOP study: Delivering within-day customer needs now and into the future

Having concluded our study, we will be hosting industry webinars to summarise key findings and set out the next steps we will be taking as part of the RIIO-T2 Network Capability work stream.

Click one of the options below to sign up.


The level of linepack swing managed within-day has increased despite gas demand decreasing. This shows that how our customers choose to use their capacity and flow gas on and off the network has changed.

We want to ensure the right ‘rules, tools and assets’ are in place, at the right time, to continue to meet future within-day network needs.

Instalment 3: South east focus study

In a previous publication we highlighted that the south east is sensitive to within-day flows. We have therefore looked at this region in more depth to better understand the challenge of accommodating within-day customer needs.


Key findings

Our physical network’s ability to transfer gas in and out of the south east plays a crucial role in enabling customers to bring gas on and off the network in a manner that suits their commercial and operational needs.

Managing imbalances in gas brought on and off in the south east: as forecasted by the Future Energy Scenarios, LNG and Interconnector flows are anticipated to increase. Therefore, gas entering the south east could grow. The importance in our capability to transfer gas out of the south east to manage linepack levels in the region may become increasingly important.

Managing within-day behaviour: a sudden change in the amount of gas brought on or off at a location can create significant operational challenges in meeting customer needs in the south east, especially if this occurs when national linepack levels are already declining or increasing.

Next steps: Through the RIIO2 Network Capability work stream, we plan to replicate this south east analysis across the whole network. If potential gaps in both our ability to accommodate future regional imbalances or within-day flows are identified, we will be considering the development of new commercial tools/market solutions as well as asset solutions.


Instalment 2: Forecasting future within-day behaviour


Using your insights, we have forecast how within-day supply and demand behaviour could evolve by 2025, and the resulting impact on levels of linepack swing managed.

Key drivers for increase in:

supply-driven linepack swing
  • Reductions in UK Continental Shelf (UKCS) supply is replaced by sources whose within-day delivery rates are typically less constant (interconnectors and LNG).

  • Further refinements in interconnector and storage compressor fuel usage and gas spot price spread optimisation could lead to more within-day volatility in delivery rates.

demand-driven linepack swing
  • Increased proliferation of renewables could lead to more frequent increases and decreases in gas-fired generation within-day demand. Ultimately, this would increase within-day linepack swings.
  • Increases in small-scale gas-fired power stations connected to Distribution Networks could lead to higher contributions to linepack swing.

Instalment 1: Understanding within-day behaviour

We have been engaging with stakeholders to better understand current and future within-day behaviour. Below is a summary of the insight we have gathered to date.

About this study

In our first GFOP publication, we showed that how gas is brought on and off the network can create operationally challenging conditions. From our analysis, the degree of challenge depended on the assumptions we made about future within-day behaviour.

Through this study, we want to:

  • better understand what influences how gas is brought on and off the network and how this could change in the future

  • test our physical network's capability to continue to meet future within-day needs

Timeline and outputs

This study will be released as four instalments, each building on the findings of the previous one. After each instalment, you can:

  • provide insights to enhance the next stage of our study
  • challenge our analysis so we can review, refine and republish
  • help shape the scope of future studies so that outputs are of most benefit for the market.

Your input will help to outline the future within-day needs of the network.

Instalment 1

Output:Summary of how within-day flows have changed, and factors influencing behaviour

Release date: 14th February 2019

Instalment 2

Output:Predict how within-day gas flows could change by 2025

Release date: 28th February 2019

Instalment 3

Output:Assessment of our physical network’s capability to continue to meet future within-day customer needs.

Release date: 28th March 2019

About the authors: Jon Dutton is a gas network strategy manager in Gas Operations, where Imran Abdulla is a senior analyst and Adeolu Adesanya is a lead economics analyst.