Transport service tariffs


2018 was the third year of the new regulatory period, the term of which has been increased from four to eight years (2016-2023) divided into two sub-periods: the first four with method continuity, the method for the others to be subsequently implemented.

“Integrated Text of dispositions of the Authority for supplying electricity transmission and distribution services (TIT)”, Annex A to resolution 654/2015/R/eel, the “Integrated Text of dispositions of the Authority for the supply of the electricity metering service (TIME)”; Annex B to resolution 654/2015/R/eel, and the “Integrated Text on dispositions of the Authority for the economic conditions for supplying connection services (TIC)”, Annex C to resolution 654/2015/R/eel, published on 23 December 2015.


For the distribution service, ARERA confirmed unbundling of the tariff applied to end customers (the so-called compulsory tariff) from the reference tariff for determination of the restriction on revenue permitted to each company (the reference tariff).

The regulations in force in 2016 include:

Regulatory lag and return on invested capital;

Extension of regulatory useful life;

Tariff adjustment criteria: cost coverage, measurement.

With regard to the first point, the ARERA has changed the manner for offsetting the regulatory lag, recognising new investments made both for Distribution and for measurement (no retroactivity).

The criterion based on the increase in the investment rate of return granted to new investments, equal to 1% (year t-2), has been replaced by recognition in the capital base (RAB) also of the investments made in year t-1, evaluated on the basis of pre-final data communicated to ARERA. These data will be used for the determination of the provisional tariffs of reference published by 31 March and then replaced by the final data for the determination of the definitive tariffs of reference published by February of the following year. On 15 March 2018, the ARERA published the definitive reference tariff for the electricity distribution service for the year 2017 with resolution 150/2018/R/eel. On 29 March 2018, the ARERA published the provisional reference tariff for the electricity distribution service for the year 2018 with resolution 175/2018/R/eel.

In the year t, the ARERA only recognises the remuneration of the invested capital concerning the assets which entered use in the year t-1, without recognising the relevant amortisation rates (which are still recognised in the year t-2).

With reference to depreciation recognised in the tariff, the new regulation increases the useful regulatory life of certain assets, such as HV electric lines (increased from 40 to 45 years), MV and LV lines and "end users' connection points” (from 30 to 35 years).

The rate of return on net invested capital (WACC), whose calculation parameters were published in Resolution 654/2015/R/eel, is 5.6% for the distribution service on the investments made until 31 December 2017.


In terms of operating costs, the new company-based tariff covers the specific costs by means of a national average cost adjustment coefficient, calculated by the ARERA on the basis of actual company costs and on the basis of scale variables.

These costs, when calculating the company-based tariff, according to the definitions of Resolution No. 654/2015, are supplemented by flat rate connection contributions acknowledged throughout Italy, and will be considered as other grants and no longer deducted from operating costs.

Furthermore, the flat rate connection contributions of each company are deducted directly from the invested capital considering them as equal to MV/LV assets.

Updating of the distribution reference tariff after the first year is individual and based on financial increases reported by the companies on the RAB databases. The updating criterion envisages that:

the portion of the tariff covering operating costs will be updated using the price cap mechanism (with a productivity recovery target of 1.9%);

the part intended to provide a return on invested capital will be updated on the basis of the gross fixed investment deflator, movements in the volume of services provided, gross investments started up and differentiated according to the voltage level and the rate of variation linked to increased returns designed to provide incentives for investments;

the part intended to cover depreciation has been updated, using the gross fixed investment deflator, movements in the volume of services provided and the rate of variation linked to the reduction in gross invested capital as a result of disposal, discontinuation and end of life, and the rate of variation associated with gross investments that have become operational.


The ARERA confirms for 2017 the mechanism, already introduced in the third regulatory period, for the higher remuneration of certain categories of investments made until 2015, not extending this mechanism also for the 2016-2023 cycle.

As regards marketing activities, the ARERA introduces a single reference tariff that reflects both the costs for managing the network service and marketing costs, with recognition of the specific capital costs also for investments in marketing activities.


With regard to the transmission tariff, the ARERA confirmed the introduction of a binomial tariff (capacity and consumption) for high voltage customers, and the cost tariff structure for the transmission service to Terna (CTR), also introducing a binomial price. Given the two tariffs, the equalization mechanism has been confirmed.


The general equalisation mechanisms for distribution costs and revenue for the regulatory cycle in force are:

equalisation of distribution service revenue;

equalisation of transmission costs;

equalisation of the difference between actual and standard losses.

Starting in 2017, the ARERA has introduced a tariff applied to home customers that is no longer divided between D2 and D3 but single (TD), as specified in resolution 799/2016/R/eel dated 28 December 2016, leading to the removal of the calculation mechanism for the equalisation of revenue from the supply of electricity to home customers, in force until 2016.


In the new Transport Integrated Text, the ARERA has confirmed the mechanism of advance recognition on a two-monthly basis, of equalisation balances for revenue from the distribution service and transmission costs.


The Measurement Integrated Text (TIME) governs tariffs for the metering service, divided into meter installation and maintenance, taking meter readings, confirming and recording readings. The structure of the fees has been changed compared to the previous regulatory period only with regard to the fees for collection and validation of meter readings, previously broken down and now unified into a single fee.

The ARERA has introduced a new method for recognising the cost of capital in relation to low voltage electronic meters, for companies that supply the service to more than 100,000 withdrawal points, based on the recognition of investments actually made by the individual firms confirming the criterion for determining the metering service tariff on the basis of the national cost for remote management systems and for electromechanical meters still in place (residual cost), maintaining the metering equalisation also for the fifth regulatory period to equalise the surplus deriving from the comparison of the obligatory tariffs billed to end users and the revenue valorised in the reference tariff. The equalisation mechanism is intended to equalise the revenue from the comparison of the obligatory tariffs billed to end users and the revenue valorised in the reference tariff.

On 29 March 2018, the ARERA published in resolution 174/2018/R/eel the definitive tariff for metering activities in 2017. On 29 March 2018, in resolution No. 176/2018/R/eel, the ARERA published the provisional reference tariff for the 2018 electricity metering service.

The tariffs covering the metering service are updated, as for the distribution service, by price cap mechanisms for the part covering operating costs (with a productivity recovery target of 1%) and by the deflator, change in invested capital and rate of change in volumes for the part covering invested capital and depreciation. The rate of remuneration of the measurement capital is the same as that for the distribution service.


In resolution 646/2016/R/eel dated 10 November 2016, the ARERA described the methods of defining and recognising costs concerning the second generation (2G) smart metering system for metering low voltage electricity. On 8 March 2017, it published a release in which it updated the evaluation of the plan for entry into service of the 2G smart metering system prepared by e-distribuzione S.p.A.

Starting in 2017, and only with regard to the investments that come into operation in 2017, the ARERA has established in the same resolution that for the annual updating of the return on invested capital and depreciations concerning metering points effectively in low voltage, for each distribution firm, the maximum gross investment value recognisable per meter installed in 105% of the corresponding gross investment value per meter for the investments that came into operation in 2015.


The “Integrated Text on dispositions of the Authority for the economic conditions for supplying connection services (TIC)”, Annex C to Resolution 654/2015/R/eel, governs the economic terms for the provision of connection services and specific services (transfers of network equipment requested by end users, contract transfers, disconnections, etc.) to paying end users, essentially in line with the previous regulatory period.