Quality of gas distribution
The distribution service consists of the withdrawal of natural gas from Snam Rete Gas pipelines, by means of first-stage withdrawal points, and its transportation through local gas pipeline networks for delivery to end users. A gas distribution system is typically composed of:
- main supply natural gas distribution networks (pressure greater than 5 bar), medium pressure networks (greater than 0.04 bar up to 5 bar) and low pressure networks (up to 0.04 bar);
- RE.MI. substations (acronym for Regulation and Measurement) or first-stage substations, where a first reduction in the pressure of the gas taken from the Snam Rete Gas high pressure pipelines is made. The RE.MI. plant consists of the complex of equipment where the gas undergoes filtration, pre-heating, pressure reduction, measurement and odorization;
- user-derived systems, the complex of pipes and accessory devices that constitute the installations necessary to supply the gas to the end customer. The user-derived system starts from the gripper (the part of the system used to withdraw the gas from the main pipe by conveying it, through a pipe with a smaller diameter, towards the meter) and extends to the measurement group (meter).
Gas distribution is carried out by the Group in compliance with the rules of functional separation for companies vertically integrated into the sector, in compliance with the principles of cost-effectiveness, profitability and confidentiality of company data with the aim of promoting competition, efficiency and adequate service levels.
The use of innovative technologies for laying and maintaining the networks means that necessary activities can be performed while reducing time frames and costs and keeping disruption to residents to a minimum. Security is guaranteed via remote control systems, a 24-hour emergency service, the cathodic protection of the steel networks, the use of odorised gas and regular and scheduled inspection of the network.
The Group also manages the distribution of LPG, in particular in the province of Reggio Emilia (21 storage tanks) and in the province of Genoa (7 storage tanks), located in places not yet reached by the natural gas network. Suppliers deliver the pre-odorised LPG in tanks, the Group distributes it to customers at a pressure of 30 mbar and ensures safety through remote control of the plants. The LPG distribution activity is closely connected to the gradual “methanisation” of the area.
The Group is continuing with the progressive installation of electronic meters which, as well as providing real- time data for billing the relative amounts due and speeding up certain activities (activation or deactivation of a supply, consent, etc.), help to raise residents’ awareness about their energy usage, promoting behaviour aimed at reducing and improving gas consumption with subsequent benefits for the environment.
|Installed gas meters (no.)||2021||2020||2019|
|Total gas meters||812,940||811,606||809,899|
|of which electronic||712,096||675,041||613,303|
|% electronic meters||87.6%||83.1%||75.7%|
In relation to the commercial quality parameters for gas distribution, ARERA has defined standards which provide for the automatic compensation to customers in the case of non-compliance.
|Commercial quality levels (business days)||2021||2020||ARERA max time|
|Cost estimate for simple jobs||9.9||7||15|
|Cost estimate for complex jobs||13.1||12.5||30|
|Execution of simple jobs||6.4||7.1||10|
|Reactivation following deactivation due to non-payment||1.2||1.3||2 working days|
Leaks in the gas network and interruption of service
Gas interruptions occur mainly during network renovation works when the user connections are switched from old to new pipelines. The interruptions are divided into scheduled outages, if the works are planned and it is possible to promptly communicate the interruption to the citizen, and unscheduled outages, that is, those for which it is not possible to notify all the customers involved, since they are generally caused by a local failure in a part of the network or damage caused by a third party.
In the case of scheduled outages, in order to limit the inconvenience to the end customer, the work is carried out with the help of plugging with by-pass systems that allow the work to be carried out without suspending the flow of gas..
In 2021, the easing of restrictions due to the Covid-19 emergency led to an increase, compared to 2020, in excavations by third-party contractors – the main cause of gas pipeline damage – and this resulted in a slight increase in unscheduled outages as a consequence, although maintaining the trend of strong improvement over 2019.
|Gas distribution interruptions (no.)||2021||2020||2019|
The main initiatives to reduce leaks in the gas network, in accordance with the provisions of ARERA, envisage the gradual cathodic protection of the unprotected steel network and the replacement of grey cast iron pipelines with hemp and lead joints. In 2021, in addition to the search for leaks on the underground network established by ARERA, the systematic search for leaks also continued at the measurement groups.
Network leaks are up compared to 2020, a year that recorded an exceptional reduction mainly due to lower customer/ citizen reports during the pandemic period; considering a longer time horizon, the trend is significantly positive (-24% compared to 2019). The most numerically significant leaks come from overhead utility derivation plants.
The project to replace the gas network with new steel and polyethylene pipes also continued in 2021.
|Gas network replaced (km)||2021||2020||2019|
|Cast iron pipes||5||3||4|
Safety of the gas network
People’s safety is dominant in gas distribution service. The use of competent and adequately trained resources, together with a continuous monitoring of the network, are factors that contribute decisively to the prevention of accidents and are subject to continuous analysis and improvement, in order to increase their effectiveness with respect to efficiency.
Network inspection, an effective emergency service and an adequate odorant concentration are fundamentally important for a proper management of a distribution system, together with a continuous modernisation of the networks.
ARERA establishes the safety service obligations, including network inspections. In 2021, Iren Group inspected 8,029 of the 8,158 km of the gas network managed. Scheduled inspection has also led to a greater control of leaks.
|Gas network inspected||2021||2020||2019||ARERA requirement|
|Low pressure network||97.3%||15||84.0%||≥ 25%|
|Medium and high pressure network||99.2%||100.0%||95.0%||≥ 33%|
|Total network inspected||98.4%||98.8%||88.0%|
In 2021, over 98% of gas networks were inspected: more than three times the number of inspections required by ARERA
ARERA also sets minimum levels of odorants for service safety and the protection of people and things. In 2021, Iren Group injected over 45 mg of odorants (tetrahydrothiophene) into the network for every cubic metre of gas distributed, a higher amount than that established by ARERA (32 mg/m³), which means that its presence in the air can be noticed easier and any gas leaks identified quickly.
The Emergency Service is also essential to ensuring the safety of residents and sites. The Group’s performance in this context is significantly above the parameters established by ARERA. In 2021, the gas Emergency Service handled 7,505 calls, with an average arrival time at the call site that varies in the range shown in the table below, depending on the regions served.
|Emergency service||2021||2020||ARERA requirement|
|Average arrival time at the call site (min.)||30.4-37.9||30.6-36.5||60|
|Compliance with average arrival time at the call site (%)||97.7%||98.7%||90.0%|
In 2021, campaigns to measure the effects of noise produced on the surrounding environment did not reveal any critical issues in gas distribution plants.