**4. Massive rollout of smart gas meters in Europe**

In recent years, the European Union has played a leading role in promoting the reduction of greenhouse gas emissions in line with the ambitious new targets that fix the GHG reduction emissions levels below at least 55% by 2030. In accordance with this de-carbonization process, deep changes are required to meet these standards and a new settlement of the gas retail market needs to be held.

In order to enforce the transition to a more efficient organization for the gas system, the introduction of gas smart meters and smart metering network concepts have to be promoted as it has been already done in the electrical sector. To support these innovative changes, a new concept of consumer like a more aware and active participant in the marketplace needs to be promoted [10]. Similarly, the role of aggregators also needs to be empowered as an intermediary between small customers and network operators willing to use customers' services (DR resources) so as to manage their infrastructures more efficiently. With regard to the metering instruments and in prospective to the development of multiservice smart cities, the European Directive MID 2014/32/UE defines the functionality of measuring instruments for the promotion of efficient consumer behavior and for their active participation in the energy market. In spite of that, the Directives on the Internal Market for Electricity and Gas (Directives 2009/72/EC and 2009/73/EC) included in the Third Energy Package does not oblige European countries to participate in the rollout of the smart meter gas and does not state a deadline to complete it either. This lack of a mandatory regulation on this matter derives into different behaviors in each European country.

Similarly, to that previously done in the electrical sector, European countries have carried out a CBA for participation in the smart meter gas rollout [11].

As shown in **Figure 3**, the results were dissimilar and a slower approach to the smart meters gas introduction was registered:


In 2013, 19 European countries conducted a CBA with 12 countries showing negative CBA results (Germany, Spain, Portugal, Romania, Finland, Sweden, Poland, Czech Rep, Belgium, Greece, and Latvia). In 2018, eight Member States carried out a new CBA, obtaining coherent results with the previous one except for Austria and Ireland, where the first CBA was positive and this new one had a slightly negative result. Seven Member States did not conduct any CBA (Bulgaria, Croatia, Estonia, Greece, Hungary, Poland, and Portugal). Finally, states without natural gas networks have not been considered (Cyprus and Malta).

The latest conducted analysis among the State Members EU-28 has recognized different factors that push a country to install a gas smart meter. On one side, the two main driving factors are the digitalization of the distribution network and the optimization of the grid operation, together with the digitalization of the retail market that enables new services for private players [12]. Moreover, smart metering helps to reduce operating costs through savings in manual meter readings, theft protection, process improvement, better scheduling, and balancing processes, as well as consumer engagement opportunities. However, the participation in the massive rollout and the results of the CBA are also influenced by other factors, such as density of gas customers, gas customer expenditure, and competitiveness
