Charging an electric vehicle in the Canary Islands entails greater CO2 emissions than those generated by a traditional combustion vehicle, because the isolated electrical system of the archipelago and its energy mix uses even more polluting fuels.
This is one of the main conclusions that emerge from the study carried out by three researchers from the Department of Electronics, Engineering and Automation of the University of Las Palmas de Gran Canaria and published in the journal "Journal of Cleaner Production", under the title "A comparative evaluation of CO2 emissions between internal combustion and electric vehicles in small isolated power electrical systems - Canary Islands case study".
The research observes differences between CO2 emissions related to electric and combustion vehicles in island electrical energy systems with higher energy consumption, and only observes a small decrease in CO2 emissions in islands with better or more abundant energy storage systems and high levels of renewable penetration.
After calculating the emissions per kilometer traveled by passenger cars, it was observed that the emissions from electric cars vary between islands and even double the emissions that this type of vehicle makes on the peninsula.
Batteries are charged with electricity from fossil fuels
"The process of charging the batteries of electric cars on the islands is carried out through a mix of electricity generation with a significant contribution of fossil fuels and impactful emissions," explain Nuez, Ruiz-García and Osorio, conductors of the study.
On the island with the most penetration of renewables and energy storage systems, El Hierro, they conclude that less CO2 is emitted with electric cars than with combustion cars, so the life cycles of energy storage "play an important role and condition any future reduction in emissions".
Specifically, in El Hierro, where renewables account for 51.6% of the mix, CO2 emissions caused by electric vehicles are 12.6% lower than those generated by traditional vehicles.
Thus, the three researchers recommend that, in order to achieve the objective of electric cars contributing to reducing carbon emissions, it is necessary to increase "significantly" the penetration of renewables in the energy mix.
They also propose that the needs to have electrical energy storage options should be adequately dimensioned to obtain a true decrease in CO2 emissions during the generation of electrical energy in island systems.
The study also calls for replacing conventional generators with newer, more efficient and less polluting ones and replacing fuel oil and diesel fuel during the generation of electrical energy with other less polluting fuels such as natural gas.
The incorporation of electric vehicles as active elements to achieve this, the researchers conclude, can also be accentuated if the appropriate charging hours are selected.