International trade heavily depends on gigantic cargo ships to transport goods across oceans, and a majority of these maritime vessels consume an enormous volume of heavy fuel oil (HFO), an inexpensive but heavily polluting fossil fuel, every year.
The shipping industry has been under pressure for a drastic change to reduce its carbon footprint. Experts have set their eyes on the hydrogen-based fuel cell as a sustainable alternative. A fuel cell converts the chemical energy of hydrogen and an oxidizing agent (say oxygen from the air) into electricity via electrochemical reactions, producing water vapor as the only byproduct.
Although the technology has been around for decades, it has not been seen as a viable method for powering ships due to the lack of analyses. In 2017, things were finally moving towards the right direction as a study report released by the Sandia National Laboratories.
Commissioned by the U.S. Department of Energy (DOE), the Sandia researchers found that it's feasible to retrofit most existing vessels with hydrogen fuel cells, a cheaper and easier option as compared to constructing brand new ships from the ground up.
For the same amount of energy, liquid hydrogen is four times bigger than conventional maritime fuel in volume. But since the efficiency of a fuel cell doubles that of a diesel engine, a ship would only need twice as much capacity to produce the same energy output. By removing its existing internal combustion engine, an engineering team can easily find extra space for hydrogen storage.
The timing of this report coincides with the current trend of the "green" hydrogen production. The energy industry is slowly walking away from the traditional fossil fuel-based production method, while adopting new, carbon-neutral energy sources (e.g. wind, nuclear, and solar power) to produce hydrogen.
It's hopeful that we would one day see more and more retrofitted vessels powered by hydrogen fuel cells sail in oceans, transporting goods and "cleaning" up the century-old shipping industry at the same time.
Source: SciShow via Youtube