Electric vs hydrogen
Which systems wil lwin the race to replace petrol in the drive to build a sustainable future?
Which vehicles will win the race to replace petrol?
In the quest to protect and preserve our planet for generations to come, there is an increased urgency to design vehicles that will help to reduce air pollution and greenhouse gas emissions. We have more vehicles on our streets than ever before, and it is estimated that the gases from vehicles burning fossil fuels contribute approximately 13 per cent of the heat-trapping gases in our atmosphere.
Earth is already showing signs of climate change as temperatures have increased by 0.7 degrees Celsius over the last 140 years, causing Arctic ice to melt drastically, vast expanses of coral reef to suffer from mass die-offs and a significant rise in erratic weather. And it’s not just our planet that is affected by this — our lungs are suffering too. The International Energy Agency estimates that every year 6.5 million people die prematurely because of poor air quality, making this pollution the biggest environmental risk to public health.
The future will be pretty bleak if we don’t start changing the way we treat our planet, but there is hope. The last decade has seen a sharp rise in activism around the world to promote the importance of reducing fossil fuel emissions. We need to start powering our vehicles from sustainable sources, and many car manufacturers have jumped onboard to start doing this in conjunction with recent bans on fossil fuels being announced. Germany were the first to do this, pledging to completely ban combustion engine cars by 2030, and several other countries are following in their footsteps.
The sale of all new petrol and diesel cars will be banned in the UK by 2040, while Norway has pledged that by 2025 they will only be selling cars that are 100 per cent electric, with India set to do the same by 2030. Over half of India’s population (more than 660 million people) are living in areas where the air quality has been determined unsafe, and it is estimated people
“Germany were the first to pledge to completely ban combustion engine cars by 2030”
living there are having their lives shortened by up to three years. Piyush Goval, India’s minister of railways and coal has commented, “The idea is that by 2030 not a single petrol or diesel car should be sold in the country.”
Alternatives to fossil fuels
The journey to find a suitable fuel to sustain our future has carried researchers and developers from solar engineering and compressed gases all the way to fuels made from seaweed or alcohol. One of the alternatives that is currently being investigated is powering motors using liquid nitrogen (LN2). In this system, the specially designed engines heat the LN2 gas before extracting the heat from the air and using the resulting pressurised gas to power the motor.
The UK supermarket Sainsbury’s is trialling Ln2-fuelled Dearman engines in their lorries. They will replace the diesel engines used to power the refridgerators that keep food chilled when the vehicle’s main engine is switched off. Though relatively cheap and certainly a green fuel solution, it is far from energy efficient, so it’s unlikely that we could rely on this in the future.
Another attempt to find a green vehicle solution ditched the use of fuel altogether and built cars designed to be covered in solar panels to harness the power of our closest star. Though this sounds like a promising idea, and there are vehicles in use for solar car races, even the most efficient of this kind are limited by the amount of power they can collect because they are working with relatively little surface area.
So who are the lead runners in the race to find the power source of our future? Most experts agree that either hydrogen or electric cars will eventually prove to be the answer.
“Hydrogen and electric cars are only as green as their original electricity source”
Electric cars
Electric cars have been hailed as the future of motor travel, and they are becoming an increasingly common sight on our streets, almost silently navigating our roads. Pioneering automotive manufacturers like Tesla are leading the electric revolution, but many others have followed suit, and there are now a variety of electric cars available to the consumer.
They can be charged at home or at charging stations, are fantastically cheap to run, and they don’t emit any toxic gases. In some countries, such as the UK, the government are so keen to popularise electric vehicles that they will even contribute to the cost of your car.
Though their popularity has been hindered by their charging times, limited recharge points and short driving range, there are solutions being engineered to overcome these issues, including on-the-go wireless charging that would mean never having to plug in to charge the battery.
HYDROGEN CARS
Hydrogen cars involve a more sophisticated level of engineering, as the electricity to power their motors is generated by electrochemical reactions. They work by splitting molecules of hydrogen into protons and electrons, with the latter flowing through a circuit. In general, hydrogen vehicles have a better range than electric cars, and they are much faster to refuel, taking just a few minutes rather than the hours it takes to charge an electric car with the current technology available.
With hydrogen, fuel is pumped into the car the same way you would top up with petrol or diesel. The real drawback of hydrogen cars is the lack of infrastructure. Hydrogen is difficult to store, so you’re not able to drive freely and top up your tank anywhere. Though we are making strides in improving this, and there has been talk of having a system to produce hydrogen at home, for now this is a prohibitively expensive option. Additionally, there are concerns about the safety of hydrogen as it burns with an invisible flame, which could be dangerous if there was a leak.
POWERING THE FUTURE
At the moment electric cars seem to be winning the race. Currently, there are only three hydrogen cars available on the market — the Toyota Mirai, the Hyundai ix35 FCEV and the Honda Clarity — which are relatively expensive and currently lack the infrastructure to really boom in the zero-emission vehicle market. There are now more than 50 electric cars to choose from and the infrastructure is largely there — we just need to plug in!
It is inspiring to think that soon our roads will be dominated by cars that will no longer contribute to air pollution on the streets. However, it is important to remember that both hydrogen and electric cars are only as green as their original electricity source. Though the popularisation of zero-emission cars is a huge step in the right direction, and we’ll see a massive difference in air quality and greenhouse gas emissions as a result, the real revolution will be as we transform the national grid into a green power supply, running from solar, wind or water power rather than continuing to burn fossil fuels. The first challenges are to make zero-emission vehicles low cost and practical enough that they can become the norm, then build an eco-friendly infrastructure to support them.
“Hydrogen fuel is pumped into the car the same way you would top up with petrol or diesel”