Comparative study on the real sustainability of a petrol car versus an electric car

In the last decade, the automotive market has witnessed a shift towards electric vehicles (EVs) as a more eco-friendly alternative to traditional petrol cars. This transition has been supported by promises of reduced greenhouse gas (GHG) emissions, energy savings, and contributions to tackling climate change. However, the fundamental question remains:

Is an electric car truly more sustainable than a petrol car?

This study aims to assess the sustainability of both vehicle types, not only from the perspective of direct emissions but by considering their entire lifecycle, from resource extraction to final recycling. It is a critical exploration that reveals that, while electric cars show clear advantages in some areas, they also present significant environmental and social challenges that must be addressed.

1. Greenhouse gas (GHG) emissions

Petrol car

One of the primary arguments against petrol cars is the constant emission of GHGs during their operation. According to the US Department of Energy (DOE), an average petrol car emits between 120 and 180 grams of CO₂ per kilometre driven. These direct emissions are compounded by the impact of oil extraction, refining, and transportation, which, according to some studies, increase the carbon footprint of the vehicle by up to 30%. These impacts are particularly significant during the exploration and extraction stages, which involve risks to marine and terrestrial ecosystems and a considerable carbon footprint due to the global transport of fossil fuels.

Electric car

Electric vehicles, on the other hand, present a cleaner option during operation, as they do not emit harmful gases while in use. However, it is essential to consider the impact of battery production, which constitutes one of the main sources of emissions. According to a study by the European Environment Agency (EEA), producing a 60 kWh lithium-ion battery (typical of many EV models) can generate between 60 and 120 kg of CO₂ per kWh of battery capacity. This initial impact is significantly higher compared to petrol cars. However, if the electric car is driven for a long enough period (typically over 150,000 km) and is recharged using renewable energy sources, the electric car ultimately proves to be more eco-friendly than its petrol counterpart, despite its higher initial carbon footprint.

Comparative and partial conclusion

The main difference between the two vehicles lies in when emissions occur. While petrol cars emit GHGs throughout their lifespan, electric cars have a higher carbon footprint initially due to battery production, but over time, this is offset, especially if the EV is recharged using renewable electricity. Therefore, in terms of direct emissions and long-term energy efficiency, electric cars are more sustainable, but the energy source and the lifespan of the battery are determining factors.

2. Resource extraction and environmental impact

Petrol car

The primary natural resource used by petrol vehicles is oil, which involves several environmental impacts throughout its lifecycle. Oil extraction, whether offshore or through land-based methods, generates significant impacts on local biodiversity, affecting marine and terrestrial ecosystems, often resulting in devastating oil spills. Additionally, the global transportation of crude oil, usually via long-distance shipping, poses further environmental risks, including leaks and pollution from gas emissions.

Electric car

Electric vehicles rely heavily on rare metals such as lithium, cobalt, and nickel, materials whose extraction has considerable environmental impact. Lithium mining, for instance, in regions such as the Lithium Triangle (Argentina, Bolivia, and Chile) has raised concerns about its effects on local ecosystems, water scarcity, and the rights of indigenous communities. Cobalt, meanwhile, is mostly extracted from the Democratic Republic of Congo, where mining practices are problematic, including child labour and poor working conditions. Furthermore, the process of extracting and refining these metals is highly polluting.

Comparative and partial conclusion

While petrol cars rely on fossil fuels, which have ecological impacts, electric cars have a significantly higher environmental footprint during the resource extraction phase, particularly concerning the materials required for their batteries. The sustainability of electric vehicles largely depends on how resources are managed and the mining practices are improved, as well as advances in recycling technologies.

3. Energy use: life cycle assessment (LCA)

The Life Cycle Assessment (LCA) of both vehicle types reveals that energy use is one of the most relevant factors in the comparison. According to studies by the International Institute for Energy Research (IIER), a petrol car consumes approximately 40 to 50 MWh of energy over its entire lifecycle, from manufacturing to disposal. In contrast, an electric car consumes between 25 and 30 MWh of energy during its lifespan. This reflects the higher energy efficiency of electric cars, as, despite the energy needed to produce the batteries, the electric motor is far more efficient than an internal combustion engine.

Comparative and partial conclusion

Electric vehicles are significantly more energy-efficient. However, as mentioned, this efficiency depends on the electricity source used. If an electric car is primarily charged with energy derived from fossil fuels, the difference in energy efficiency diminishes. In contrast, if it is recharged with renewable energy (solar, wind, hydroelectric), the overall environmental impact is considerably reduced.

4. Lifespan and recyclability

Petrol car

The lifespan of a petrol car depends on several factors but typically exceeds 150,000 km without major engine issues. However, once the vehicle reaches the end of its useful life, its parts (engine, chassis, electrical components) can be recycled. While some materials can be reused, the recycling of petrol cars is not as efficient as that of other products.

Electric car

The lifespan of an electric vehicle primarily depends on the durability of the battery, which typically lasts between 8 and 12 years, or between 150,000 and 250,000 km. One of the main criticisms of electric cars is the difficulty in recycling the batteries. Although some batteries can be recycled, the infrastructure for this is still in its infancy, and the efficiency of the process is not high enough to significantly reduce the environmental impact of electric vehicles. Currently, only around 5% of lithium batteries are effectively recycled.

Comparative and partial conclusion

While electric vehicles require less maintenance than petrol cars and are more efficient during their useful life, battery recycling remains a significant challenge. In comparison, petrol cars, although requiring more maintenance, have a more developed recycling infrastructure.

5. Social and geopolitical impact

Petrol car

Oil extraction and dependence on fossil fuels create a complex geopolitical landscape, where oil-producing countries exert considerable influence over global markets. The tensions and conflicts arising from this dependence have been a constant feature of modern history.

Electric car

Although electric cars reduce reliance on fossil fuels, they create new dependencies on mineral resources, many of which are located in regions with complex social and political issues. This raises new ethical challenges related to responsible mining and respect for human rights in local communities.

Comparative and partial conclusion

Both types of vehicles contribute to geopolitical conflicts and inequalities, though in different contexts and with different implications. It is essential to address these issues globally to ensure a just energy transition.

General conclusion

The sustainability of electric vehicles versus petrol cars is complex and multifaceted. Electric cars generally offer significant advantages in terms of GHG emissions and long-term energy efficiency, provided they are recharged using renewable energy sources. However, they are not without their environmental and social impacts, particularly regarding resource extraction and battery recycling. Petrol cars continue to be responsible for high CO₂ emissions and ecological impacts resulting from oil extraction, although their lifecycle is less resource-intensive in terms of rare metal mining.

The true sustainability of electric vehicles will depend on advances in battery recycling, improvements in mining practices, and the use of clean energy for their recharging. As these challenges are addressed, electric vehicles are likely to become a more sustainable option than petrol cars, but only if global policies and technologies advance in a responsible and ethical manner.

This study reinforces the need for a holistic and critical approach to the transition to sustainable mobility, where long-term benefits are achieved through balancing environmental, economic, and social factors. It is closely connected to several UN Sustainable Development Goals (SDGs), particularly SDG 7: Affordable and clean energy, SDG 9: Industry, innovation, and infrastructure, and SDG 13: Climate action. By considering these goals, stakeholders can better ensure that the shift towards electric vehicles contributes to global efforts in mitigating climate change, reducing inequality, and promoting sustainable industries.