Future of Transportation: Electric or Fuel Cell powertrains?

Hydrogen fuel internal combustion engine is an old technology, successful experiments were conducted in 1807 by Francois Isaac de Rivaz. Electric vehicle is an old technology too, successful experiments conducted in 1827 by Ányos István Jedlik. These technologies did not become commercially successful due to limitations of storage batteries (electric vehicles) and abundance of crude oil (hydrogen fuel) [1][2].

Following the 1970s oil crisis, developed countries pushed the automobile industry to develop fuel efficient & electric powertrains [3]. Awareness by citizens about global warming & carbon footprints led to the birth of hybrids—Toyota Prius in 1997. Later, Tesla—a Silicon Valley start-up launched a luxury electric sports car with 200+ miles range in 2006[4]. In 2008, Honda launched FCX Clarity, world’s first hydrogen fuel cell car. This was followed by Hyundai’s ix35 Fuel Cell in 2013, and Toyota’s Mirai in 2015[5][6][7].

Which technology is better—electric vehicles (EV) or hydrogen fuel cell electric vehicles (FCEV)?

Firstly, we should understand the target use of vehicles. EVs are best suited for intra-city travel, which involves a huge variation in the vehicular speeds, due to different traffic patterns. EVs can efficiently deliver power as needed, and less energy is wasted in such a variable speed transit process. FCEVs are best suited for inter-city travel, which generally involves a constant speed on expressways. FCEVs are also very energy efficient; a kilogram of hydrogen contains the same amount of energy as in one US gallon (3.79 ltr, 2.83 kg) of petrol/gasoline [8][9][10].

Secondly, we should delve into the issues that make these technologies a viable alternative to consumers. Both these technologies are environment friendly, EVs have no by-products, while FCEVs release water vapour as a by-product of combustion. EV charging stations can be setup easily, which convert any AC source to DC voltage to charge batteries. The main drawback being the charging time—one hour (fast charge) to 8+ hours (full/slow charge). This long charge time creates a secondary issue—pile up of vehicles at charging stations. The charge in Lithium-ion batteries (Li-ion) diminishes slowly, if the vehicle is unused over a period of time, just as in most electronic gadgets. Tesla has invested a lot in charging stations across the US. Similar efforts are being done by others in Nordic and western European countries. Still, the long charging time for EVs is a pain point that cannot be avoided.

In case of FCEVs, hydrogen must be created by electrolysis (PEM electrolyser, environment friendly) [11]. Under present conditions—being new in the market—high cost of FCEVs and hydrogen fuel. As this technology gets widely accepted, these costs would come down drastically. The R&D investments from automobile & petroleum industry would result in ‘economies of scale’ in their production processes. The time to refuel an FCEV is typically under 5 minutes, like a regular petrol/gasoline vehicle. This makes it an attractive value proposition to consumers to adapt this technology. To increase the range of an FCEV, only a larger fuel tank is required. Whereas, an EV would require heavy and expensive Li-ion batteries, which leads to ‘diminishing returns’ after a range of 400 to 500 miles (644—805 km). Hydrogen is obtained from water, which is an unlimited resource, while Lithium—a rare earth metal with limited reserves—a complicated extraction process [12]. Today’s FCEVs have very safe hydrogen tanks, with carbon fibre jackets and safety valves, that enhance passengers’ safety in an emergency situation [13].

To conclude, going forward over the next few decades (2020-2050), the use of petroleum based internal combustion engines would be phased out or drastically reduced, while EVs and FCEVs would pick up pace in most markets. EVs would be one of the best choices for intra-city commute, while FCEVs would similarly be a good option for inter-city travel. The adoption of these new technologies would depend on the policies and environmental commitments by the citizens & governments of various countries. So, as responsible global citizens, we should push our governments to adapt to these newer and better automobile technologies.

© Sudhanshu Vuppuluri, 16-01-2020

References:

  1. https://en.wikipedia.org/wiki/Hydrogen_vehicle
  2. https://en.wikipedia.org/wiki/Electric_vehicle
  3. https://en.wikipedia.org/wiki/1973_oil_crisis
  4. https://www.energy.gov/timeline/timeline-history-electric-car
  5. http://www.fuelcelltoday.com/history
  6. https://en.wikipedia.org/wiki/Hyundai_ix35_FCEV
  7. https://en.wikipedia.org/wiki/Toyota_Mirai
  8. https://www.nytimes.com/2013/11/24/automobiles/fuel-cells-at-center-stage.html?pagewanted=1&_r=1&adxnnlx=1385313339-SWDXRwwueS6Exot9wFmA%20Q
  9. http://www.fuelcelltoday.com/technologies/pemfc
  10. https://www.aqua-calc.com/calculate/volume-to-weight
  11. https://www.energy.gov/eere/fuelcells/hydrogen-production-electrolysis
  12. https://en.wikipedia.org/wiki/Lithium
  13. https://ssl.toyota.com/mirai/assets/modules/carpagehowitworks/Docs/MY18_Mirai_eBrochure_FuelCellTech.pdf
  14. Images: unsplash.com  (Photo by John Cameron on Unsplash), commons.wikimedia.org/wiki/File:Nissan_Leaf_012.JPG, publicdomainfiles.com/show_file.php?id=14024560215339commons.wikimedia.org/wiki/File:Toyota_Mirai_fuel_cell_stack_and_hydrogen_tank_SAO_2016_9028.jpg