ZERO EMISSIONS? LET'S TALK ABOUT – Emblematic was the presentation by Professor Giovanni Lozza, which highlighted how many observers expect, by 2030, that the 30-40% of new cars will be electric. A figure that seems unjustifiable, because in the meantime there are significant technological challenges to be faced, and it is not certain that betting only on current cars is advantageous from an environmental point of view. First of all, specified Lozza, it is not right to always define them as "zero emissions": it is true that they do not have a drain pipe, but, unless they exclusively exploit renewable resources (solar, wind, hydroelectric), produce the current in a power plant involves the use of fuels, and therefore the emission of a certain amount of CO2 (the gas believed to be responsible for global warming) and, although to a lesser extent and far from population centers, pollutants (such as particulate matter, nitrogen oxides and so on). Account must also be taken of carbon dioxide emissions during the production of the car (the batteries are very impactful from this point of view, with an average of 120 kg of CO2 entering the atmosphere for every kWh of capacity).
COUNTRY YOU GO … – The advantage of using an electric car, therefore, depends on both battery capacity (the current trend of using maxi-accumulators to increase autonomy is therefore harmful to the environment) and how the current used to recharge it is produced. “Considering as a reference a distance of 150,000 km and the Hyundai Kona crossover (picture above), chosen because it is proposed with petrol, diesel, hybrid and electric – clarified Lozza – this latest version comes out clearly in a country like Norway, where practically all electricity is obtained with zero emissions: about 50 g / km emitted on average in the life cycle of the car are less than half of the 120 calculated, with a realistic use and always in the entire life cycle, for the hybrid model. However, the situation is different in Italy, where the contribution of renewable sources to produce electricity is decidedly lower and therefore leads to an average emission for the electric version of 125 g / km, a little worse than the hybrid one. In Germany, then, we are at 150, a value that coincides with that of the diesel version, and in China at 180, even worse than the petrol version, which stops at 165.
THERE IS A LOT TO DO – It is not even true that we can quickly move to a "clean" production of electricity: putting in place, and building, less impacting power plants requires many years. Here too, Lozza has shown data according to which in the world it is expected that in 2040 it will be required much more electricity of today. And if the "median" hypotheses (halfway between the most optimistic and the pessimistic ones) speak of 19,000 TWh obtained from renewable sources instead of the 8,000 today, it is also true that the contribution of gas-fired power plants will grow (from 6,200 TWh to 9,500 ) and coal (from 9.800 to 10.800). The spread of electric cars then involves the need to create adequate infrastructures. Which is not easy: taking into account the longer time needed for recharging than refueling, a motorway service station (which today has a dozen fuel pumps) should have over 60 columns for fast recharging. That is an installed power of 6 MW, the equivalent of the need of a 1,000-employee industry. In the same way, to install discreetly fast charging devices in the garages of apartment buildings, the power and size of the system should be tripled. In short, according to Lozza, the best solution (from an economic point of view, but also from an environmental point of view) requires a non-ideological approach, with a complementary use of the various technologies available, continuously evaluating the relationship between costs and benefits (if any) .
THE CHOICE IS NOT ONLY TECHNICAL – At the political level, the proportions of the problem must also be taken into account: as evidenced by Davide Bonalumi, also from the Energy department of the Polytechnic, cars circulating in Europe only contribute 0.8% to global CO2 emissions, yet they are subject to very stringent regulations: we recall that in 2021, for all manufacturers there is a limit of 95 g / km issued for exhaust as the average of new vehicles sold; those who fail will have to pay substantial "fines". This is one of the reasons why houses are focusing on the sale of plug-in electric or hybrid cars, which have declared emissions of carbon dioxide (at the exhaust, let's remember once again, and not for the entire life cycle) zero or very low, and therefore help to fall within the set limit. For Professor Angelo Onorati, we need a strategy that "does not ban the types of engines, but pushes for a reduction in actual emissions, which can be achieved in many ways". The current cars, diesel and petrol Euro 6d, with homologation tests carried out also on the road and not only in the laboratory (procedure entered into force after the dieselgate scandal) release very small quantities of pollutants. From this point of view, Onorati states, "we are moving towards zero-impact engines".
"BIO" FUELS TO REDUCE CARBON DIOXIDE – Again according to Professor Onorati, to reduce CO2 emissions (which, it should be remembered, is not harmful to human health but is a greenhouse gas), a solution can come from the use of synthetic and bio fuels, that is derived from plant sources. Almost identical words come from Mazda engineer Mitsuo Hitomi (in the picture above), a home that has just launched both some models with the innovative SkyActiv-X engine (petrol, but with a diesel-like operating cycle) and an electric crossover, the Mazda MX-30 (in the photo above). "According to our approach, faithful to the objective of proposing the right technical solution at the right time and in the right place, as long as the increasing amount of power from renewables it will not replace electricity produced from more harmful sources, electric propulsion cannot be considered satisfactory in drastically reducing greenhouse gas emissions. In fact, considering that currently in the world two thirds of electricity is produced using fossil fuels, the rules according to which the emissions of an electric vehicle are equal to zero are not relevant to reality. To correctly measure CO2, we do not consider the current tank-to-wheel estimates, from the tank to the wheel, which only consider emissions during use, but rather the well-to-wheel ones, which also include extraction, production and fuel transportation, and includes the battery life cycle, with the account of CO2 emissions from their production to disposal. ”According to the Mazda engineer, in addition to alternative fuels, such as compressed natural gas and hydrogen (for the latter, used in fuel cell vehicles , the speakers foresee a diffusion above all in the area of heavy vehicles, – the automotive industry is then carrying out feasibility research on liquid recyclable fuels such as biofuels obtained from the development of microalgae. In this sense, the development of the latter will be crucial in order to achieve the zeroing of the particulates on cars driven by the internal combustion engine. Finally, Hitomi concludes "the whole industry of electricity and battery production and the automotive industry should contribute to reducing CO2 emissions in every field". It is therefore to be hoped that the whole world will adopt an approach to global optimization of the resources and technologies available, with the only real objective of protecting the environment.