Did you know that air pollution is responsible for 4.2 million deaths per year? According to research done by the World Health Organization, 9 out of 10 people breathe air that exceeds the limits of pollutants recommended by WHO. While air pollution originates from a variety of sources, emissions from cars, trucks and buses are among the largest contributors with over 29% of all greenhouse gas emissions coming from the transport sector. In a society where motor vehicles are the preferred means of transport for most people and the energy used to power them usually comes from fossil fuels, we are prioritizing comfort over life expectancy.
These statistics, along with the global programs which promote and stimulate sustainability, are causing a revolution in the transport industry. One of the most important areas is the shift in fuels that are being used which is mainly the cause of the massive climate change we're experiencing. Global warming is a direct consequence of burning fossil fuels like gasoline and diesel which releases carbon dioxide, a greenhouse gas, into the atmosphere. The increase of the levels of carbon dioxide (CO2) and other greenhouse gases such as nitrogen gas, is causing the Earth’s atmosphere to warm, resulting in changes to the climate. Since carbon dioxide is in fact not the most harmful pollutant but it’s the one we generate the most and therefore the one that has the highest impact, a great deal of effort is done to lower the carbon emissions, so several alternatives have been developed that generate either less emissions or no emissions at all.
What are the most popular alternative fuels today?
Natural gas is among the most common known but many people don’t know that it is in fact a greenhouse gas that emits a lower volume of carbon dioxide. The way it works is that when natural gas is burned, CO2 is generated but the levels of carbon dioxide are a lot lower than in the case of other fuels. In order to reduce their carbon footprint, many car manufacturers are already substituting diesel and gasoline with natural gas, which although a fossil fuel in itself, generates less emissions.
Biofuels is another popular alternative fuel and it originates from plants that consumed CO2 throughout their lives. In order for it to be renewable, the level of emissions that are released when consuming the fuel need to balance out the emissions consumed by the plants during their lifetime. Although not as popular as cars that function on natural gas, more and more car producers have begun creating cars that work with biofuels.
Another popular alternative to fossil fuels in transportation is electricity, which is the most common alternative fuel used for cars. Electric vehicles reduce transportation carbon footprint by using batteries instead of gasoline, to power their engines. What makes an electric car sustainable or not is the origin of the electricity. If the electricity doesn't come from a renewable source, it’s not considered to be sustainable. For example, if fossil fuels are used to create electricity, then that electricity doesn’t qualify as being renewable. Electric vehicles are the most popular alternative means of transport but although they are efficient and environmentally friendly, they also have a few disadvantages such as limited autonomy and long recharging times.
An alternative to electric cars are hybrid-electric vehicles (HEVs) that combine the advantages of both the internal combustion engine, or gasoline engines, and the electric motors that use energy stored in batteries. Aside from being environmentally friendly, hybrid-electric vehicles have several other advantages such as dual power, which means the power is optimized so it can come from either the engine, motor or both depending on the situation, they can start or stop automatically, and they are also affordable.
Which are the alternative fuels of the future?
Hydrogen is popular because whether it’s used in a fuel cell or burned to create heat, its only emission is clean water. Although it is the best alternative to fossil fuel, it also comes with a few challenges which are mainly related to the cost of producing it and transporting it safely. To begin with, despite being one of the most abundant elements on Earth, hydrogen is not easy to obtain, since it’s not found in nature, but is generated from other substances that contain it such as water, coal or natural gas. The ideal way to produce it would be using water, a substance present in 70% of the planet. However, obtaining it from water would require to carry out a process called electrolysis, which consists of the decomposition of water molecules (H2O), into oxygen (O2) and hydrogen (H2). This is generally an expensive process that requires a lot of electrical energy.
Given that it is a gas, whenever it is transported or stored, it needs to be condensed almost into a liquid which presents high risks of leaking or even more dangerous, explosions due to the high pressures. Similar to biofuel and electricity, hydrogen also qualifies as renewable only if it’s produced with renewable resources which in this case is electricity. If the electricity used in generating hydrogen is renewable, then that hydrogen becomes green hydrogen.
The advances made in the field of hydrogen as an alternative field have already made possible the first cars that run on hydrogen. The gas is used to generate the electricity that drives the vehicle, by combining hydrogen with the oxygen in the air. It is therefore an electric vehicle, but with the difference that its energy is generated directly in the car. This in turn is what makes the hydrogen car such a valuable alternative. By generating electricity from a gas, the autonomy of this type of vehicle is greater because it is not powered by a battery which needs recharging. In fact, one of the latest Hyundai models that was released, the Nexo, can travel up to 666 km, it only needs six to eight minutes to recharge and it has 0 emissions.
Although hydrogen fueled cars have the best qualities of both combustion as well as electric vehicles, they’re nowhere near as popular because of several reasons such as the difficulty in producing hydrogen or the lack of hydrogen refueling stations. In order to produce hydrogen, large amounts of electricity are needed and once it’s produced, the transportation process itself is challenging because the gas needs to be condensed at high pressures, which increases the risk of an explosion.
The scarcity of hydrogen recharging stations is another important challenge. In Spain, there are only six stations and they’re not completely open to the public as they’re still in a testing phase. Without developing the proper infrastructure that has a vast network of hydrogen charging points and without finding a safe solution to easily condense and transport the hydrogen to the charging stations, the commercialisation of hydrogen vehicles might still be a topic of the future.
However, several countries have begun adopting hydrogen cars. In 2019 Japan had only 3,600 hydrogen cars on the road, but the goal is to increase that number to more than 811,000 by 2030. Second up are the Netherlands, who plan on having 300,000 fuel cell cars operating also by 2030.
Governments and corporations alike are fighting to control climate change and minimize its effects. International programs such as the Paris Agreement and the EU Green Deal are regulating emissions and imposing limits in several industries with a high carbon footprint, one of which being the transport sector.
Although alternative fuels such as natural gas, biofuels, electricity or hydrogen are viable solutions for replacing fossil fuels without compromising our lifestyles, the shift to these sources of energy depends on overcoming many limitations. First of all, governments need to build an infrastructure of charging stations for hydrogen and electricity. Service stations need to go through a digital transformation which would allow them to commercialize other types of fuels. There are also logistical challenges such as the need to minimize the high risks of producing or transporting some of these fuels such as hydrogen. There are a number of limitations on the technological side, although many advancements have been made with mobile apps, for example, facilitating payments. Although these constraints might seem insurmountable, these limitations need to be addressed. The shift to alternative fuels is necessary in order to lower the level of emissions and ultimately, control climate change.