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4.3.1 ›

RNTIAT Operation


The indicators set out in the Quality of Service Regulations (QSR) had the following annual values:


Average nº of interruptions per output point


Average time of interruptions per output point

0 minutes

Average duration of interruption

0 minutes


- Average No of interruptions per output point: ratio between the total number of interruptions at delivery points during a specific period, divided by the total number of delivery points at the end of the period under consideration. - Average duration of interruptions per delivery point: ratio between the sum of interruption durations at delivery points during a specific period, divided by the total number of delivery points at the end of the period under consideration.

- Average duration of interruption: ratio between the sum of interruption durations at delivery points, divided by the total number of interruptions at delivery points, in the period under consideration.

The remaining indicators for the of supply and characteristics of natural gas fell within the limits set by the QSR. 

The aggregate indicator for the frequency of incident occurrence per year per 1,000 kilometres of high-pressure transmission infrastructure for 2016 stood at 0.043, based on the total infrastructure exposure time. Considering only the last five years it is 0.147. The value of the same indicator published by the European Gas Pipeline Incident Data Group (EGIG) for all TSOs participating in the scheme is 0.177 for the last five years.


Compliance with commercial service (nominations)


Injection of natural gas into the network (injected/requested)


Facility availability


- Compliance with nominations for natural gas withdrawal: the ratio between the number of nominations complied with and the total number of nominations.
- Compliance with nominations for natural gas injection: the ratio between the number of nominations complied with and the total number of nominations.
- Compliance with energy storage: determined based on the mean square error between nominated and real energy values of both injection into and withdrawal of gas from underground storage.


With regard to REN Atlântico infrastructure unavailability, in 2016 a total of 8 hours and 1 minute was recorded, of which 5 hours were planned. These figures correspond to installation availability of 99.97%.

Internally, 56,774 hours of work were carried out and and no accidents were recorded. 

In terms of subcontracted workers, 27,376 hours of work were carried out, also without any accidents.


Compliance with commercial service (nominations)


Injection of natural gas into the network (injected/requested)


Facility availability



In 2016, the intake of natural gas into the infrastructure operated by the RNTGN concession holder was mostly through Campo Maior (63.9%), which connects with the Maghreb gas pipeline and supplies Portugal with gas mainly from Algeria. The intake from the regasification of liquefied natural gas at the Sines Terminal of REN Atlântico stood at 32.1%. Grid input points via underground storage and Valença do Minho were equivalent to 3.5% and 0.5%, respectively, of the total intake into the national system. The following graph shows the weighting of intakes into the system:


In 2016, the 56,595 GWh (around 4.76 bcm) transmitted through the RNTGN included high-pressure national consumption, with a total of 54,513 GWh (4.58 bcm), the injection of natural gas into underground storage of 1,834 GWh and withdrawal of 248 GWh (0.02 bcm) of natural gas for Spain through the Valença do Minho-Tuy interconnection.

With regard to the use of system capacities, in 2016 the maximum daily entry figure for the RNTGN through the Badajoz-Campo Maior interconnection was 138.5 GWh recorded on 25 August, and 185.7 GWh through Sines on 22 December. These peaks show that maximum input capacity was reached at Campo Maior and 96% use of LNG regasification capacity was seen at Sines.

With regard to the interface with underground storage, maximum daily withdrawal reached 70.0 GWh on 2 January while injection reached 27.1 GWh on 10 August. Maximum use of capacity was also seen at this interface.

With regard to system management of the infrastructures in the National Natural Gas System (SNGN), in 2016, different activities were carried out which required intervention in relation to the coordination of natural gas flows. This had significant impact on several entities in the SNGN, also involving the operator of the interconnected network.


Of special note:

(i) operations limited due to PIG inspection in the batch 6 gas pipeline (Cantanhede-Mangualde) and in the batch 7 gas pipeline (Sines-Setúbal);

(ii) operational support for the Spanish system in the supply of natural gas to Galicia in the months of November end December through the transfer of gas from Portugal to Spain at the Valença do Minho interconnection.

One of the key events of the year was the implementation on 1 October of Regulation (EU) No 312/2014 establishing a Network Code on Gas Balancing of Gas Transmission Networks, allowing full compliance with national obligations in this regard. During implementation, support was provided for stakeholders, as the new rules introduced numerous changes to the normal use of the infrastructures, particularly with regard to the national transmission system. This support was provided with the aim of ensuring rapid stabilization of all processes.


With the implementation of the network code for network balancing as of the last quarter, added responsibility was introduced for infrastructure users to balance their positions in the transmission system. As of the last quarter and in accordance with the new rules, market agents are now responsible for maintaining a constant balance in their entry and withdrawal flows in the transmission system. With this aim in mind, they are encouraged to purchase any gas required or sell surplus gas in this infrastructure by using the Mibgás gas transaction platform directly. Mibgás was appointed as the Portuguese operator of the organized market in Portugal and can start operation in 2017. This entity is now particularly important in this new situation with regard to network balancing.

In order to compensate for the absence of a market operator in Portugal, ERSE decided that gas purchase or sale requirements by the system manager for residual balancing of the transmission system would be satisfied through an auction mechanism. This rule would remain in effect over a transitional period, which started in the fourth quarter of 2016.

With regard to activity in the high-pressure infrastructure (SNGN), 2016 saw the start-up of five new market agents. New access contract processes were also started by other market agents wishing to sell gas. In total, REN has 19 active suppliers registered to use the high-pressure infrastructure.

During 2016, the e_Switch platform was also updated. This platform manages the Supplier Changing Process (GPMC) and the update was to bring it in line with current regulations. 


A summary of GPMC activity is given below:

    • The total number of clients registered at the end of 2016 stood at 1,427 million with more that 76% of the national total in the free market regime. This is an increase from the 71% of 2015 of 89,805 clients; 
    • In relation to consumption, it must be mentioned that, in December, the corresponding free market value stood at 96% of all demand in Portugal;.
    • In 2016, taking into account the main flows in the switching process, 278,513 requests were successfully concluded. Average weighted conclusion time was eight days, lower than the reference target (15 days). 

Further to the approval of Law No 7 - A/2016 and the respective implementation through Ministerial Implementing Order No 178 - C/2016, with the materialization of the automatic award of the social tariff where GPMC operates as the hub between ORPE and DGEG, 36,000 end users were awarded the said social tariff. This corresponds to approximately 2.6% of total delivery points in mainland Portugal, and an increase of around 39% when compared to the previous award mechanism.


With respect to supply security and RNTIAT planning, draft reports were drawn up on the assessment of risks affecting natural gas supply security in Portugal, on the preventive action plan and on the emergency plan. This ensured compliance with the provisions of Regulation No 994/2010 and Decree-Law No 231/2012. These documents will be discussed with the competent authority, the DGEG, in the first quarter of 2017. It is expected that that they will be completed and sent to the European Commission during the first semester of 2017. On a European level, REN took part in the process to review Regulation No 994/2010, both through representation on ENTSOG as well as by collaborating with the DGEG in the Gas Coordination Group (GCG).



Also with respect to RNTGN infrastructure operation, in 2016 work was continued on programmes to update technology in management systems and applications, more specifically:

    • Metering systems, with the installation of ultrasound counting systems and replacement of flow computers;
    • Development of Remote Data Transmission Units (RTUs) to allow the future integration of IP technology and provide remote access to these terminals;
    • Installation of of new gas quality chromatograms to allow improved determination of NG characteristics as provided by the RNTGN.
    • Implementation of a new control concept for the odorization system so as to make use of the pre-odorized NG received by Campo Maior;
    • Integration of the linear and mobility module into the Maximo maintenance tool to provide greater efficiency in infrastructure maintenance and operation processes, also allowing future integration with PIMS - Pipeline Integrity Management System;
    • In 2016, REN-Gasodutos concluded the implementation of an Integrity management system for its pipelines (PIMS - Pipeline Integrity Management System). As a vital part of the asset management system methodology, the inventorying and digital recording was carried out for all existing data on gas pipelines in the RNTGN. The PIMSlider programme was also introduced to provide decision support, allowing the optimized and efficient management of infrastructure security in compliance with the National Natural Gas Transmission Network Regulation No 142/2011, and in line with best European practices in the sector.


With regard to operations, the LNG Terminal received a total of 26 ships in 2016 (22 unloading and three loading operations and one cooling operation), corresponding to total unloaded energy of 21.9 TWh and issue of 18.3 TWh to the network. In the same period, 4,629 tankers were loaded, of which 1,196 were for the island of Madeira, corresponding to total energy of 1.33 TWh.

The maximum daily issue from the terminal into the network was recorded on 22 December, with a total of 187.3 GWh.


Ten audits were carried out along with two inspections and all had positive results. With regard to audits: three were conducted under the SEVESO directive (two internal audits and one external audit for certification monitoring) in connection with the verification of the integrated quality, environment, occupational health and safety management system; two audits (internal and external) relating to the ISPS Code; one requested by the insurance company and one within the scope of the APS concession contract. Inspection work was conducted by the Directorate General of Geology and Energy (DGEG) and by the Directorate General of the Agriculture, Sea, Environment and Spatial Planning (IGAMAOT).

One safety drill was conducted with the participation of external entities, which tested the response capacity of REN Atlântico and other bodies involved in safety (PEI-SEVESO).


In 2016, the following aspects were of note in underground storage:

    • Commissioning of the first stage of the compression system upgrade;
    • Maintenance of the compressors and motors in the compression unit;
    • Inspection of the cavities RENC-1, RENC-4 and RENC-5;
    • Inspection of production tubing in cavities RENC-1, RENC-3, RENC-4 and RENC-5;
    • Cleaning of tri-ethylene glycol from the auxiliary circuits in the gas dehydration unit.

With regard to the use of underground storage, total natural gas movement was 3,828 GWh, broken down into 1,994 GWh of withdrawals and 1,834 of injection. Overall self consumption by the gas station in 2016 corresponded to 10 GWh.


At the end of the year, compared with 2015, the following balance of stocks was seen:

(GWh) (1)
1.402 1.570 -11%
(GWh) (2)
'16 '15 VARIATION '16/'15 (ENERGY)
1.358 1.648 -18%


At 31 December 2016, the nominal capacity figures for REN Armazenagem’s six caverns in operation were as follows:

  '16 '15

Maximum capacity



Effective maximum capacity after technical restrictions



Commercially available capacity



Cushion gas



- Cushion gas: permanent volume of gas maintained in cavities in order to ensure
the minimum pressure required to safeguard their structural stability.
- Maximum capacity: total capacity minus the cushion gas volume.
- Maximum e ective capacity after technical restrictions: maximum capacity minus
the volume restrictions for using the caverns due to technical constraints.
- Commercially available capacity: maximum e effective capacity after technical restrictions
minus the capacity allocated to the SNGN technical system manager for operational reserves.