Ultimately, it’s about building a sustainable future on this beautiful planet we call home…
Well, we’ve explored electric cars, and solar cars (which are a form of electric cars), and this week we wrap with a couple of final alternatives, before moving onto travel stories gathered on our recent Mpumalanga Trip…
As discussed in the previous newsletters, the ecological reality is not necessarily only the emissions from the vehicles, but the manufacturing process and the source of their power and whether or not they are clean, green, feasible and ecologically friendly.
Let’s examine Hydrogen powered vehicles – which are, essentially, also electrical vehicles (EVs). In 1807, Francois Isaac de Rivaz (a Paris-born Swiss inventor) designed the first hydrogen-fuelled internal combustion engine. Dr. Roger Billings ignited the hydrogen energy movement once again when, in 1966 as a high school senior, he made the first hydrogen-fuelled car. These days hydrogen is even being used to send NASA rockets into space. This year there are many vehicles running on hydrogen, from London buses and forklift trucks, to the Toyota Mirai, the Hyundai Nexo, and the Honda Clarity. Whilst hydrogen cars haven’t exactly taken the world by storm, they do offer a greener option to petrol and arguably a viable alternative to battery-powered EVs.
A Toyota hydrogen fuel cell concept vehicle.
In a nutshell, fuel cells mix stored hydrogen gas with oxygen – and this electrochemical reaction produces electricity. This is then used to power an electric motor, without any toxic emissions. The only by-products of the whole process are water and heat, as a result of the connection of hydrogen and oxygen atoms that form H20 molecules. These hydrogen cars represent a unique segment of the market, and they’re also called FCVs (Fuel Cell Vehicles) or FCEVs (Fuel Cell Electric Vehicles).
Beyond driving without any polluting emissions, they are quickly refuelled in 5-10 min (compared to the best-case scenario of 40 minutes of charging, or the more common scenario of 3-6 hours of charging, in electric cars). They’re also usually able to achieve longer distances than electric cars (due to the fact that 1kg of hydrogen apparently stores 236 times more energy than 1 kilogram of lithium-ion batteries). Hydrogen fuel cells do not produce noise pollution and the problem of the end of the lithium batteries (used in EVs) life cycle disposal is mitigated.
What we do today affects their future…
One limitation on hydrogen cars is the fact that there are so few hydrogen refuelling stations at the moment. In January 2021, there were 45 publicly accessible hydrogen refuelling stations in the US, 43 of which were located in California. By comparison, there were a total of 96,536 public electricity charging ports.
Although hydrogen is the most common element in the universe, it doesn’t exist in its pure form on earth. So, to use as a fuel, it needs to be produced out of other compounds. To do this, energy is required, and environmental and economic costs enter the equation.
There are basically two methods used to “create” hydrogen. We can obtain hydrogen by reversing the electrolysis process of water (considered a ‘clean’ process – but very expensive, as it uses high amounts of energy). If the energy required for this process is obtained from renewable sources (sun, wind etc), the overall energy cycle is very carbon low and the process becomes more environmentally-friendly. A downside of this method is that this process is only 75% efficient (thus losing 25% of the electricity).
Most hydrogen fuel is obtained using the second method – the process of natural gas reforming, which is much less expensive than electrolysis. This unfortunately produces harmful by-products (e.g. carbon dioxide and carbon monoxide) which contribute to global warming. Methane (at least 25 times worse than CO2 for the environment) leaks while extracting natural gas are common and the process of extraction (known as “fracking”) has huge ecological impacts.
There is also an energy loss conundrum which exists.
With a battery electric vehicle, once the electricity is generated, about 5% is lost during the process of supplying this to the vehicle charging location. Another 10% is lost during the process of charging and discharging the battery. The motor then loses another 5% when the car is being driven. So, you have a total loss of around 20%.
On the other hand, with a hydrogen fuel cell, you first convert the electricity to hydrogen via electrolysis, which is only 75% efficient. Another 10% is lost when the gas is compressed, chilled and transported. The fuel cell process of changing the hydrogen back to electricity is only 60% efficient, after which you have the same 5% loss from driving the car. The total loss is more than three times as much.
And so, once again, there is no simple answer…
Before we leave this subject, let’s once again plant the seed of Nuclear Fusion Power – or “Fusion Energy”. Unlimited, clean and ultimately cheap. We dealt with this in a previous newsletter, but it bears mentioning again as it could, just possibly, solve all our energy issues – forever! We’re just not quite there – yet…
Jacqui Ikin & The Cross Country Team
A fascinating history of nuclear-powered cars: