Hydrogen used in fuel cells has the energy to weight ratio ten times greater than lithium-ion batteries. Consequently, it offers a much greater range while being lighter and occupying smaller volumes. It can also be recharged in a few minutes, similarly to gasoline vehicles.
How Does A Fuel Cell Work?
A fuel cell is a device that generates electricity through an electrochemical reaction, not combustion.
In a fuel cell, hydrogen and oxygen are combined to generate electricity, heat, and water. Fuel cells are used today in a range of applications, from providing power to homes and businesses, keeping critical facilities like hospitals, grocery stores, and data centers up and running, and moving a variety of vehicles including cars, buses, trucks, forklifts, trains, and very soon…. YACHTS & SHIPS.
Fuel cell systems are a clean, efficient, reliable, and quiet source of power. Fuel cells do not need to be periodically recharged like batteries, but instead, continue to produce electricity as long as a fuel source (Hydrogen) is provided. As there are no moving parts, fuel cells operate silently and with extremely high reliability.
Is Hydrogen Safe?
Safety regulators see hydrogen in concept to be similar to other chemical fuels when compared to batteries. In the hydrogen-based powertrain, you have fuel storage where fuel is always kept separate from the oxidizer – except for that small amount that flows into the fuel cell.
On the other hand… charged Li-ion batteries include fuel and oxidizer sealed internally in one package, impossible to separate if something goes wrong. External heating or internal short circuits can lead to thermal runaway effects in large-scale, high-energy-density batteries… these events are very hard to contain. Once a battery fire starts, for example, it’s very difficult to stop.
So, it’s quite different and, if anything, the safety authorities are unclear about how to deal with batteries as opposed to chemical-based fuels like hydrogen.
Then you look at things like ignition temperature of hydrogen – much higher than petrol or diesel fuel. It’s practically impossible to pool hydrogen in one place or maintain a concentration in the open air. It’s very lightweight, it escapes very quickly. Diesel and petrol have vapors that are heavy, and they concentrate around the leaked fuel. Those can ignite easily.
So, from a safety perspective, the fundamentals of hydrogen are better than incumbent marine fuels and batteries.
Once you do the math and begin to understand what technologies are available and practical, you’ll quickly focus on hydrogen-fuel-cell-based powertrains. There’s nothing else that really works as well.
Batteries are too heavy, biofuels cannot scale, hybrids with diesel or LNG engines don’t eliminate GHG… none really makes sense – you’re increasing the complexity of the powertrain for relatively limited gain in cruising range.
What remains are hydrogen-based propulsion methods. One is hydrogen-electric, and that’s what Zeroc is doing with fuel cells. Another is synthetic fuel, which uses the same internal combustion engines (ICE) as you have in ships today but produces fuel from hydrogen into synthetic liquid fuel. The latter is more expensive, requires more energy and still has all the disadvantages of liquid fuel burning, particulate emissions, nitrogen oxides, ICE maintenance, and so forth.
Zeroc Energy thinks that hydrogen-electric is going to be the dominant force overtime in clean sea navigation, and that’s why they’re doing it.Email This Post