Aerial view of a road running through farmed fields

The E-mobility Emission Saving Tool

The innovative algorithm that can calculate the real health and environmental benefits of electric mobility.

The Benefits

An innovative tool that’s capable of providing accurate information by tapping into the Enel X Way ecosystem.

What is the e-Mobility Emission Saving Tool?

With all the effort we’re making in terms of sustainability, we decided to quantify it by calculating the amount of CO2 saved through the use of electric vehicles. And that is why we developed the e-Mobility Emission Saving (e-MES) tool, an algorithm which does just that. The steps are simple: we convert the kWh provided to power electric cars into an amount of CO2 that’s been saved from entering the environment, by calculating the equivalent emissions that would have resulted from using internal combustion engine vehicles (ICEVs).

How do we calculate it?

Through our infrastructure, the following information is available to us:

  • the number of recharging events in progress at any one time;
  • the total amount of energy delivered.


The data used to calculate the emissions saved is sourced from the recharging infrastructure - for both public and private use - in Italy that's connected to the Enel X Way Integrated Platform. The fact that this infrastructure is “always connected” enables better and easier collection of the data required for the algorithm.

How many equivalent trees?

In order to make our calculation easier to relate to, we decided to take it a step further: taking the CO2 saved from supplying a certain amount of kWh and converting it into an equivalent number of trees. Enel X Way is keen to shine a light on the incredible effort being made to improve the sustainability of mobility through the electrification of road vehicles, with the transition from thermal to electric powered, and to measure the resulting saving in CO2 emissions, also in terms of the trees/year equivalent.


Data regarding the quantity of kWh supplied comes from the Enel X Way Integrated Platform, which centrally manages all the information relating to the charging services. This data comes from the different recharging facilities connected to the system across Italy. The Fast and Quick public and private access facilities (both PoleStation and JuicePole) are equipped with MID-certified internal meters.

The connected wallbox-type facilities for private use are equipped with an integrated meter that’s calibrated during production.


The CO2 calculation commences with an estimate of the distance travelled by electric vehicles, more precisely 100% electric Battery Electric Vehicles (BEVs) or Plug-in Hybrid Electric Vehicles (PHEVs) in electric-only mode. The factor used is the average consumption of electric vehicles currently on the market, calculated by the Politecnico di Milano in the paper: “Apriamo la strada al trasporto elettrico nazionale” (“Paving the way for national electric transport”)*.


In order to convert this distance travelled into CO2, calculations are based on the average emissions produced by the vehicles currently on the road in Italy, using data published by the ISPRA Institute. The figure is updated annually.

kWh supplied

Enel X Way's integrated platform manages the data coming from the public and private access points connected to the charging infrastructure.

Distance travelled

The number of kilometers travelled is estimated based on the average consumption* of electric vehicles currently on the market, as calculated by the Politecnico di Milano.

ICEV emissions

The CO2 that would have been emitted by conventionally powered vehicles, taken from ISPRA data on average annual vehicle emissions across Italy.

CO2 saved

The net CO2 savings can be calculated, once the CO2 that is emitted to produce the kWh used has been determined, based on the current national energy mix.

Equivalent trees

Using the amount of CO2 absorbed by a tree in one year, it’s possible to calculate the equivalent number of trees for that amount of CO2 saved.


* The electric vehicle consumption figure is expected to remain constant over time, and refers to the consumption of BEVs or PHEVs in the electric-only mode. Currently, electric vehicles are already extremely efficient vehicles. In fact, the electric engine is already highly efficient (over 90%), so it is unlikely to improve significantly over time. The consumption largely depends on the vehicle’s weight and aerodynamic coefficient: 

1. The aerodynamic drag is already contained via very high levels of efficiency, with Cx = 0.28 for C-segment cars, largely thanks to design considerations aimed at increasing the range and quietness of the vehicles, as well as a number of inherent advantages (e.g., a flat underside due to there being no central exhaust system).

2. The weight is already low, thanks to design considerations aimed at increasing the vehicle’s range. The engines are already very light and powerful (there’s no reason to increase the power further, 150 hp for a hatchback has already been achieved), so the only element that could be optimized is the battery (its specific weight). The trend is to increase capacity while keeping the size the same. 

The Enel X Way customer's forest on 4 wheels

By deducting the amount of CO2 emitted to produce the kWh used for electric mobility (source: ISPRA report), we arrive at the “net” CO2 saved through using electric vehicles rather than combustion engine vehicles. By then applying a ratio for the amount of CO2 absorbed by a tree in one year (2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories), the equivalent number of trees can also be obtained to quantify “the forest on 4 wheels that each Enel X Way customer has created through their responsible behavior with respect to the environment around them.”


One of the issues most often linked with electric mobility, aside from polluting emissions, is the silence associated with operating an electric vehicle. This issue was particularly evident during the initial Formula E and MotoE races, in which the vehicles taking part whizzed by at incredible speeds, so that spectators could only hear the noise of displaced air, rather than the roar of their engines.


Enel X Way wanted to accurately and definitively calculate the reduction in the level of ambient noise offered by the adoption of electric vehicles or plug-ins used in the all-electric mode. This was with respect to vehicles powered by internal combustion engines, both non-rechargeable hybrids and those that are entirely thermal. Studies carried out by CEDR were used to conduct this analysis: they highlighted a significant reduction in noise emissions between 20 km/h and 50 km/h. 

Indeed, above 50 km/h, the noise emanating from

the wheels on the road and the aerodynamic penetration render the noise emissions of vehicles largely equivalent, no matter how they're powered. Under 20 km/h, BEVs are equipped with acoustic devices to make it easier for pedestrians to hear them. Considering this speed range, the difference in the overall noise generated by BEVs and HEVs (Hybrid Electric Vehicles) is 4-5 dB(A) at 20 km/h and 2 dB(A) at 50 km/h. The difference in overall noise between BEVs and manual diesel-powered ICEVs is as high as 14 dB(A) at 20 km/h and 6 dB(A) at 50 km/h.


Taking a conservative approach, and to offer a rapid assessment of the “gain” obtained through the use of electric vehicles, we can assess the overall noise reduction as being 3 dB(A) compared to internal combustion engines. Indeed, just a 3 dB(A) reduction is equivalent to 50% less noise deriving from road traffic. Using an EV in all-electric mode, as opposed to an HEV/ICEV is equivalent, in noise pollution terms, to a halving of road traffic volume. In other words, every km covered by a vehicle in all-electric mode reduces the amount of noise emitted into the urban environment (at speeds of between 20 and 50 km/h) by the equivalent of that emitted by two HEV/ICEVs covering the same distance.


This practically means that Enel X Way, as of March 2021 through its recharging services, reduced the amount of noise emitted into the environment by the equivalent of almost 30,000 internal combustion engine vehicles driving around Italian cities.

Not just CO2, also particulates and nitrogen oxides

Enel X Way, through the e-MES tool, is also looking to underline the incredible effort being made in terms of the reduction in other pollutants, which can have a major impact on public health, entering the environment. Indeed, road transport leads to the emission of small pollutant particles of varying size (hence PM 2.5 - PM 10, generically PMx, i.e., particulate matter), which generally come from two sources:

  • the application of brakes and tires rolling on the road;
  • emissions from internal combustion engines.

While the former is significantly reduced with electric vehicles, thanks to regenerative braking

that uses the electric engine as a kinetic energy converter, the latter is completely avoided. Regarding the exhaust gases produced by thermal powered vehicles, in addition to CO2, they also include nitrogen oxides (NOx) which, like PMx, are highly toxic to living organisms, if emitted into the environment.

As in the case for CO2, by taking into account the emissions generated by Italy’s electricity production system, Enel X Way has created an algorithm that converts the kWh supplied through the charging infrastructure into a quantity of polluting substances that would otherwise have been emitted into the environment: the e-MES tool.

Financially quantifying the health and environmental benefits of Enel X Way e-mobility

Enel X Way decided to financially quantify the impact of reduced atmospheric and noise emissions linked to the recharging services it provides, including in terms of the health and environmental benefits generated. In order to do so, it used the “EC Handbook of the External Cost of Transport” version 2019 1.1, a document written by the European Commission with the objective of making it possible to calculate the negative externalities generated by transport in terms of greenhouse gas emissions (typically CO2), pollutants (NOx and PMx) and noise pollution.

Using e-MES 3.0, Enel X Way is able to calculate, as of March 2021, a total financial saving, thanks to e-mobility, of more than € 3.7 million for the community since it commenced its activities. Based on Motus-e*** projections, according to an Enel X Way estimate calculated using the e-Mobility Emission Saving tool, by 2030 a total of over €400 million will have been saved in terms of health and environmental benefits generated, thanks to the public recharging services.


*** “The future of electric mobility: the recharging infrastructure in Italy @2030”

The e-Mobility Emission Saving tool validated by RINA

The e-Mobility Emission Saving algorithm is the first algorithm to be validated by RINA (an official Italian certification organization) for this specific purpose.


Evaluation of the saving in CO2 greenhouse gas emissions (calculated in accordance with the principles identified in “ISO 14064-2:2019 Greenhouse gases” Part 2), polluting gases such as PMx and NOx, and noise pollution, and the financial quantification of the negative externalities on health and the environment, in accordance with methods and emission factors indicated in the principal reference sources.