We all know that fossil fuels won’t last forever, to say nothing of their carbon footprint. We need to clean up our act when it comes to transportation and think about how we can get from A to B more sustainably.
We could use active modes of transport (walking, biking, etc.) or public transport (bus, train, etc.). Still, there’s no getting around the fact that if you’ve got a lot of stuff to carry – taking furniture or a bunch of plants for the garden home from the shop, for example – these options aren’t a goer. I’ll talk about those active modes more in another post, but I know, and you know, there are times when a car is the most realistic option. We cannot return to using ox carts or horse-drawn wagons when we need to take loads and a large family.
Given that cars are a necessity for many people (but not everybody), it’s important to think about how we can be more sustainable in our transportation options – what’s known as green motoring. For many people, the simplest option is to switch from a car with a large engine to something smaller. Although that’s a good start and does help cut down the carbon footprint, these small-engined vehicles still rely on fossil fuels. Much more can be done to clean up our act and drive sustainably.
There are three pathways to sustainable or green motoring: electric vehicles or EVs, hydrogen power and biofuels. Here, I will give you the basics on all of them so you can work out which one is best for you.
Electric Vehicles
Electric vehicles (EVs) are getting much attention from governments and car manufacturers. These are the sexy side of sustainable motoring – and we get a reminder from Tesla’s different models (S, X, 3 (which looks like a backward E) and Y). Almost every motoring manufacturer has read the signs of the times, and they’re all making EVs.
EVs come in two main types: hybrid and full battery (BEVs). Hybrids use a regular internal combustion engine and an electrical motor; BEVs use just the electrical motor.
How Does It Work?
A fully electric vehicle or BEV uses electricity to power the wheels – it’s as simple as that. The principle of the motor is the same as any electrical motor, like the sort you find inside a blender. The electrical motor inside a BEV or EV is more potent than kitchen appliances, but the basic working principles are the same.
Unlike the toys we got as presents as children, batteries are included in an EV, and they’re rechargeable. Like all batteries, the electrical potential energy is used up when you ask them to do things, and the batteries run flat. This means that the batteries have to be recharged. This can be done at home with an in-home charging point or at one of the many public charging stations nationwide.
Advantages
EVs are quiet and don’t emit any pollution from the motor when it’s in use. They also don’t stall (one of the big problems with learning to drive something with an internal combustion engine) and don’t have a complicated gearing system. There aren’t any complicated power and torque curves because full power and torque are always available.
Disadvantages
The two main disadvantages of EVs are charging issues and range. Charging is a simple process, but it’s a lengthy one. This can be a problem when demand is high, as happened in London just before Christmas 2022. However, as more and more charging points become available, high-speed charging points, this problem is likely to clear up. The range is something that the manufacturers are working on. Even so, it’s important to remember that the range you’ll see advertised with a new model of EV is what they get under test conditions. You will likely get different results depending on the weather conditions, what you’re carrying, how you drive and what else you ask the car to do (lights, heating, charging your phone, etc.).
One other issue is the problem with sourcing lithium, as many (but not all) sources of the lithium needed for the rechargeable batteries are from developing countries, and the process of mining them can be a bit dodgy in some situations in terms of how sustainably it’s done and how they treat the workers.
The other issue is the problem of generating electricity. All the power used to charge an EV must come from somewhere. Some ways of generating electricity are more sustainable than others, and this is something that we need to think about.
Hydrogen Power
A hydrogen-powered vehicle uses hydrogen as a fuel – not for burning but for generating electricity for powering an electric motor. A vehicle that uses hydrogen is sometimes called a hydrogen fuel cell.
How Does It Work?
Hydrogen gas goes into a fuel cell (you can think of this as a battery), and the gas molecules are split into an electron, which makes electricity, and a proton. This chemical reaction produces two things: electricity and water. The electricity runs the motor and everything else in the car. The water goes out the back in the form of exhaust. Fresh hydrogen gas is pumped into the car’s fuel tank when it runs low, like petrol or diesel.
This is still comparatively new technology, and only a few hydrogen fuel cell cars are on the market. However, the manufacturers and other developers are working on this and the best way to safely manufacture, store and transport the hydrogen gas.
Advantages
A hydrogen vehicle has all the advantages of a battery EV when it comes to emissions, carbon footprints, and noise. However, they are quicker to refuel, as the hydrogen fuel for the fuel cell is pumped in. The range in a hydrogen vehicle is about what you’d get from a car with an internal combustion engine.
Hydrogen is a super-abundant resource, and the gas can be obtained from water (even dirty water – it doesn’t need clean water) with some electricity. The process means that electricity and water produce hydrogen, which is then turned back into electricity and water. And on it goes.
Disadvantages
Hydrogen fuel cells are expensive because the catalysts that split the hydrogen atoms into protons and electrons are rare metals such as platinum. This means that the cars are costly. The problem is that hydrogen is a volatile gas, so transporting and storing it can be tricky (although they’re working on this). Because it’s such a new technology, there aren’t many places where you can refuel hydrogen vehicles… at least not yet.
Biofuels
Biofuels are like fossil fuels (and can be chemically identical), but they don’t come from fuel reserves. Instead, they are produced in a short time and are made from (mostly) plants. There are two types of biofuel used for motoring: bioethanol and biodiesel.
Some biofuels are made from vegetable waste products, such as leftovers from the sugarcane industry or the wood industry. Others come from oil-bearing plants such as maise and jatropha. Others come from algae. There are a lot of sources, so I’ll have to talk more about these in another post.
How Does It Work?
Biofuels work just like your regular combustion engine – they can be pumped into a standard car. Often, biofuels are mixed with fossil fuels to help the engine run better.
You may ask how biofuels are sustainable. The answer is that they cut down on carbon emissions because they come from plants. The carbon that comes out of the back of a vehicle running on biodiesel was part of a plant last year and was in the atmosphere the year before, so they’re not adding any new carbon to the atmosphere. They also burn cleaner than conventional engines, creating less pollution.
Advantages
Biofuels can run in your current vehicle, so you don’t need to buy a new one. Biofuels are already used widely around the world, often as mixtures. The infrastructure is already in place for fuelling stations.
Disadvantages
Biofuels still pump out pollutants from the exhausts. Because they need to be mixed with fossil fuels, they still contribute to carbon emissions.
There’s also the issue of all the inputs (water, pesticides, fertiliser) needed to grow the crops used for biofuels and the problem of fuel crops competing for space with food crops. However, marginal land, waste products (such as the stems of maise) and plants that grow with minimal inputs are often used. The algae used for biodiesel are grown on sewage and wastewater, so that doesn’t compete with other crops or people for clean water.