We wanted to quantify sustainability efforts through the use of e-vehicles in terms of CO2 Saving and so created a bona-fide algorithm: e-Mobility Emission Saving.
It’s simple: we convert the kWh used by e-vehicles into the equivalent quantity of CO2 emissions saved by considering the emissions that would have been released by combustion engines.
How do we do it?
Through our infrastructure, we have access to data regarding:
- the number of charging sessions taking place at any given moment
- total amount of charging energy supplied.
The scope of the e-Mobility Emission Saving tool is defined by the charging infrastructures (public and private) in Italy linked to the Elettro Mobility Management Platform (EMM) system. These structures are permanently “connected” which provides efficient and effective data gathering for the algorithm.
How many trees?
To increase the impact of our calculations, we went even further: from kWh supplied to CO2 Savings to the equivalent number of trees required to absorb that CO2.
The Elettro Mobility Management Platform (EMM) is a central management system that handles information about charging sessions at various public and private infrastructures.
The distance covered (km) is estimated using average e-vehicle consumption* based on models present in the market, calculated by the Polytechnic University of Milan.
Using data published annually by ISPRA, which provides the average emissions for the entire fleet of vehicles in circulation in Italy, it is possible to calculate the amount of CO2 that would have been emitted by internal combustion engines.
Once the CO2 emitted in producing the kWh used (which depends on the national energy mix) has been determined, it becomes possible to calculate the Net CO2 Saving.
Equivalence in trees
The amount of CO2 absorbed by one tree annually is used to calculate the number of trees required to effect the same CO2 Saving.
Enel X wants to demonstrate its deep commitment to sustainable mobility through the electrification of the vehicles in circulation in the country, the shift from fossil fuels to electricity, and the consequent saving in CO2 emissions, additionally measuring this in terms of equivalent number of trees per annum.
The data concerning kWh is supplied by the Elettro Mobility Management Platform (EMM) system that centralises information from the different charging infrastructures connected to it in Italy. The Fast and Quick (Pole Station and JuicePole) infrastructures for public and private use are supplied with an internal measurement calculator (MID certified), while others, e.g. Wallbox for private use, contain a measurement calculator, integrated and calibrated during the production process.
The CO2 calculation considers an estimated distance covered by e-vehicles that are either 100% electric (BEV) or hybrid Plug-ins (PHEV) used in all-electric mode.
The average consumption of the e-vehicle models available on the market was calculated by the Polytechnic University of Milan in the research document: “Apriamo la strada al trasporto elettrico nazionale” (Pave the way for national electric transport).
The distance covered was converted into CO2 by using the average emissions for the total vehicle fleet in circulation in Italy, as calculated by ISPRA and updated on an annual basis.
Enel X clients’ forest on four wheels
The net “CO2 Saving”, obtained with the use of electric rather than fossil fuel-powered vehicles, is calculated by detracting the quantity of CO2 emitted in producing the kWh used in e-mobility (source: ISPRA). Using the estimates for the quantity of CO2 absorbed annually by one tree (Source: 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories), it is also possible to calculate the saving in terms of the equivalent number of trees and thus quantify “the forest on 4 wheels created by Enel X clients through their environmentally responsible behaviour.”
One of the themes most often linked with electric mobility, aside from polluting emissions, is the silence associated with operating an electric vehicle. This theme was particularly evident during the initial Formula-e and Moto-e races, in which the vehicles taking part whizzed by at incredible speeds leaving the spectators only to hear the noise of displaced air, rather than the roar of their engines. Enel X 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, with respect to vehicles powered by internal combustion engines, both non-rechargeable hybrids and those that are entirely thermal. Studies carried out by CEDR (the Conference of European Directors of Roads) were used to conduct this analysis; these studies 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 (Battery Electric Vehicles) 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 in order to offer a rapid assessment of the “gain” obtained through the use of EVs, we can assess the overall noise reduction as being 3 dB(A) compared to internal combustion engines. The logarithmic nature of noise is also reflected in the relationship between noise and the volume of traffic*. Indeed, just a 3 dB reduction is equivalent to 50% less noise deriving from road traffic. Using an EV in all-electric mode – as opposed to an HEV/ICEV (Internal Combustion Engine Vehicle) – 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. It practically means that Enel X, as of March 2021 through its recharging services, has reduced the amount of noise emitted into the environment by the equivalent of almost 30,000 internal combustion engine vehicles driving around Italian cities.
*cit. EC Handbook of the external cost of transport, version 2019 1.1
Financially quantifying the Health and Environmental benefits of Enel X mobility
Enel X 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. 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.On the basis of e-MES 3.0, Enel X 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. Using the Motus-e projections, by the year 2030*, according to an Enel X estimate, the e-mobility emission saving tool will have enabled savings of over €400 million in terms of Health and Environmental benefits generated thanks to the public recharging services.
*Motus-e study "The Future of Electric Mobility: the Recharging Infrastructure in Italy @2030" ….-calculations based on 2020 data, applied to an estimate of 9.9 TWh of total demand in Italy and 28% propensity towards using public charging points. https://www.motus-e.org/wp-content/uploads/2020/10/Il-futuro-della-mobilit%C3%A0-elettrica-linfrastruttura-di-ricarica-in-Italia-2030-2.pdf
*Data regarding e-vehicle consumption (BEV or PHEV in all electric mode) are considered constant through time. Today’s e-vehicle is already an extremely efficient machine. The electric engine has a very high performance rate (over 90%), which makes it unlikely that there will be significant improvements in the near future. Consumption depends principally on a vehicle’s weight and aerodynamic coefficient:
1. Aerodynamic impact is first tackled in the design phase at high levels of efficiency (with CX=0.28 per segment C), giving great consideration to range and noise levels. E-vehicles have intrinsic advantages (e.g. the lack of a central exhaust system allows for a flat chassis).
2. Weight is kept to a minimum in the design phase for reasons of range and engines are already very light and powerful (there is no reason to increase the present power capacity - already 150CV for a station wagon). This means that the battery (which has a specific weight) is the only element that could be further optimised. However, the trend here is to increase its efficiency within the present dimensions.
The e-Mobility Emission Saving tool is the first algorithm validated by RINA for this specific purpose and scope.
The e-Mobility Emission Saving algorithm is the first algorithm to be validated by RINA (Registro Italiano Navale ed Aeronautico) for this specific purpose. Evaluation of the saving in greenhouse gas (CO2) emissions (calculated in accordance with the principles identified in ISO 14064-2:2019 "Greenhouse gases Part 2"), polluting gases PMx, 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.