Project Update
Stockholm: pressure management for leakage reduction
Background
Gasnatet Stockholm is highly committed to reducing leakage and the company’s environmental impact, and so decided to work with Utonomy on a ‘Proof of Concept’ (PoC) project for the UtonomyOne solution, in order to confirm that it could be applied to Stockholm’s city gas network, with the aim of ultimately enabling them to automatically reduce and monitor their network pressures overnight.
Gasnatet Stockholm has a good record in reducing methane emissions caused by gas leakage from the distribution network. Having already achieved the Global Warming Potential 2025 goal ahead of time in 2014, they went on to decrease the leakage of gas and fogger oil from the city gas network by more than 22,720 tonnes of CO2eq/yr in the twenty years leading up to 2022.
Stockholm’s city gas network is made up of about 30 twin-stream pressure reduction stations, operating at a fixed outlet pressure of 15mbar. Manual pressure reductions overnight had already effected a saving in lost gas of up to 25%.
Participants
Gasnatet Stockholm AB manages the city’s gas distribution infrastructure. It is a subsidiary of Vartan Gas AB, which is owned by British investment company, iCON Infrastructure. iCON also owns Stockholm Gas AB which supplies the gas to the consumers.
The Swedish Gas Authority oversees regulations and safety standards for gas distribution across Sweden. They were involved in assessing the UtonomyOne solution for this project.
The UtonomyOne solution
UtonomyOne is an intelligent pressure management solution, designed to reduce gas leakage in distribution networks by automatically adjusting and optimising pressure levels. The system has been successfully implemented on various networks in the UK and across Europe, where it has significantly reduced leakage and emissions. The solution’s core functionality revolves around its ability to dynamically control network pressures based on near-real time data, which minimises stress on the network and reduces the likelihood of leaks.
Deployment in Stockholm
In Stockholm, the UtonomyOne PoC project consisted of two phases:
- Lab testing: performed to ensure the system could operate effectively at pressures of 10-15mbar, as required by the Stockholm gas network.
- Field trials: to demonstrate the solution’s effectiveness in a real-world setting
Ucontrol, the retrofittable actuator part of UtonomyOne’s system architecture, was tested during this project. It was installed at the pressure reduction station, providing autonomous set-point scheduling to control the outlet pressure of the station, reducing pressure during off-peak times and thereby minimising leakage.
While Ucontrol alone was tested during this PoC, the next project stage features all components of the UtonomyOne solution: Uconnect, Ucloud and Uscope, which together provide remote visibility and monitoring of the pressure reduction stations. This enables operators to see the operating pressures of the network, remotely change and update the set-point schedules, and receive any alarms and alerts in near-real time.
Benefits
On the trial network, Gasnatet Stockholm has successfully reduced the overnight average system pressures from 15mbar to 12mbar using Ucontrol. This equates to a 20% reduction in overall methane leakage.
Johan Skansing, Head of Gas Distribution at Gasnatet Stockholm, commented:
‘We are delighted to have such great results, and looking forward to working with Utonomy again to connect up Ucloud and Uscope in the next phase of the project covering further strategic sites on our network.’
