Battery-powered and hydrogen cars are both types of electric vehicles. What differentiates them? Which one is more convenient, and which more sustainable?
How BEVs and FCEVs work
While a traditional ICE (Internal Combustion Engine) is powered by burning fuels through spark or compression, a BEV (Battery Electric Vehicle) uses electricity stored in a battery pack to power its electric motor and turn the wheels. Because there is no combustion involved in powering electric cars, they don’t emit any direct carbon emissions and help with the reduction of air pollution.
FCEV (Fuel Cell Electric Vehicles) are also electric vehicles. However, instead of being powered by a battery pack, these vehicles have a hydrogen fuel cell. To put it simply, the fuel cell uses stored hydrogen and mixes it with oxygen from the atmosphere to produce energy to run the vehicle on one hand and emitting water as byproduct on the other. Because the electrochemical reactions produce a lot of heat, discarded water becomes steam. Just like the BEVs, hydrogen cars do not produce any polluting tailpipe emissions.
Both battery-powered vehicles and hydrogen cars generally cost more than their equivalent petrol and diesel models.
The cost of BEVs range from around £21,000 (Skoda Citigo-e iV, range 160 miles) to over £100,000. For BEVs, the elevated price usually derives from the lithium battery they use. However, as the battery sizes decrease, the cost of electric cars is also decreasing. In 2015, the battery made up 57% of the cost of a midsize electric car in the US. This year it makes 33%, and by 2025 it is expected to make up just around 20% of the overall cost.
On the other hand, prices for hydrogen cars start from around £50,000. At this price point, carmakers are still believed to be losing money on every model sold. The reasons for the elevated cost of FCEVs are primarily the low number of models produced and the high cost of the platinum needed in the fuel cell.
Running costs & Infrastructure:
If you are able to charge your battery-powered electric vehicle from a domestic charger, the costs of running your vehicle will be very low. Depending on the average cost of electricity where you live and the capacity of your vehicle, cost per mile could sit around 4-6p. There are currently more than 25,000 electric vehicle chargepoints in the UK.On-street charging will be more expensive than charging at home, but it will still be less expensive than refueling a petrol or diesel engines.
Hydrogen cars are considerably more expensive to run. According to Rac, it will cost between £50 to £75 to refuel one of the three available models in the UK with a range of 300 miles. It is also worth mentioning that there currently are only 17 active hydrogen refuellers in the UK.
The range of a BEV depends on the size and capacity of its battery, which in turn significantly influences its price. Most of the recent models on the market have a range of over 100 miles. To add miles to a battery-powered electric vehicle, you need to add more battery cells, which increases the overall weight of the vehicle, which in turns affect its range.
But it is possible to purchase a BEV with an impressive range – if you have the savings for one. The Tesla Model S has a range of 335 miles. It is important to note that BEVs range is influenced by external temperatures, so colder weather might affect your BEV’s range.
On the other hand in FCEVs, hydrogen is stored in light-weight tanks and it accumulates energy much more efficiently than battery packs: 1kg of hydrogen can store over 200 times more energy than 1kg of lithium-ion batteries. For these reasons, most hydrogen cars easily cover 300 miles from a tank. This means that the average range of a FCEV equals to the range of one of the best BEVs on the market. The range of hydrogen cars is also independent from outside temperatures.
The charging times for BEVs range widely from several hours (around 8 for a Nissan LEAF to get fully charged on a slow domestic charger) to around 30 minutes (for a Tesla on a 120kW supercharger). This depends on the size and capacity of the car’s battery in relation with the type charging stations and charger connector.
Hydrogen cars are clearly the winners with regards to charging times. Whereas battery-powered electric vehicles are charged by running electricity into them, FCEVs are refueled by pumping pressurized hydrogen into the vehicle. And because of the superior capacity of hydrogen to store energy compared to lithium-ion batteries, a hydrogen vehicle can be fully charged and ready to go in less than 5 minutes.
The biggest drawback of hydrogen cars has to do with the harvesting process oh hydrogen. Although hydrogen is the most common element on our planet, it does not naturally exist in its pure form. Currently in the UK, as well as in the US, most hydrogen is produced through a process of natural gas reforming, generating carbon monoxide and dioxide as byproducts. In other words, the environmental benefits of driving hydrogen cars are nullified by the pollutants emitted when producing hydrogen to begin with.
Greener methods of hydrogen harvesting exist. One of them is electrolysis: the process of splitting the hydrogen from the oxygen in water. If the energy used for this process came from renewable, this could be a carbon neutral way to produce hydrogen. But the real issue with electrolysis is that it needs a massive amount of energy, even more than reforming natural gas. There is around 30% energy loss during electrolysis, which makes it highly inefficient.
FCEVs enthusiasts place their hopes in the development of a new production process, which has the potential to reach over 85% overall efficiency: proton-exchange membrane. During this process, water flows through this proton-exchange membrane, which acts as a filter, only allowing protons to move through it. Effectively, this is a much more efficient way of splitting water molecules than electrolysis. This process needs a lot of improvement and work, but it also has the potential of hydrogen being produced directly at refueling stations, with no need for transport or bulk storage.
The bottom line is, though, that in order to power up FCEVs, you need to produce energy twice: once to produce hydrogen, and once again to have hydrogen power the vehicle. This is why (together with the poor infrastracture), at least for now and for the foreseeable future, BEVs are the most efficient option.
To charge up battery-powered electric vehicles, in fact, the process is rather straight-forward: the energy runs directly from the grid to the vehicle and powers the motor.
Of course, the production of the electricity itself needs to be looked at: it needs to come from renewable energy. Choosing an EV charging network powered by clean energy makes BEVs pretty clean.Those who have the option of charging their vehicles at home could also consider installing solar panels and produce their own energy sustainably.
Overall, hydrogen fuel cell vehicles are extremely attractive due to their fast refueling time and their range. The production of hydrogen is currently the biggest issue for the roll out of FCEVs, together with its lack of infrastructure. This might change in the future, but the amount of research and technology advancement needed to make hydrogen vehicles suitable for the public’s everyday life will take time.
Battery-powered electric vehicles, on the other hand, are already an efficient and sustainable transport option and represent a wise investment for the future.