Is this prototype the next step toward realistic green planing power?
With an ever-sharpening focus on climate warming, questions are being raised about the concept of fossil fuel boating. At this moment in time, zero-carbon or low-carbon boating lags behind the automotive industry, and for good reason. Planing powerboats have big power needs, so only craft like the hydrofoiling Navier N30, featured in this issue, have any chance of providing the pleasure boater with a degree of realistic use on the water. However, Torqeedo, one of the first pioneers of electric propulsion, have teamed up with H2 Marine Solutions in Holland to produce an interesting hybrid RIB: the 6m H2C. I use the term ‘hybrid’ loosely as there is no fossil fuel involved, but rather a combination of a hydrogen fuel cell and a lithium-ion battery, both supplying a Torqeedo Deep Blue 50R 60kW electric outboard.
The 60kWh Deep Blue is the equivalent of an 80hp petrol outboard
Bavaria-based Torqeedo released their first 60kW outboard back in 2012. This has now been developed into the current 60kW Deep Blue 50R, providing the equivalent power of an 80hp petrol engine. The H2C, whose electrical energy is provided by a 284kg 40kWh lithium battery, will have range limitations with just this energy supply alone. Back in 2012, I tested the first-generation 60kW Torqeedo, which was then supplied by a 28kWh battery and ran near the red after 30 minutes of spirited use. Though energy density in lithium-ion batteries has improved over the last decade by around 30%, H2 Marine have not opted to plumb in the bigger 80kWh 562kg battery that Torqeedo now offer. They have reduced displacement as much as possible with the 40kWh battery and put the power emphasis on the 51kWh hydrogen fuel cell, which can also supply the 360 volts that the Deep Blue needs. This fuel cell will be fed by a 120L fuel tank, pressurised to 700 bar, which when full at this pressure relates to just 4kg of fuel. Hydrogen (H2) is the lightest element on the planet, so 120 litres of it carries a fraction of the weight of fossil fuel. The fuel cell itself is made by UK company Intelligent Energy.
The 40kWh battery is slim enough to fit under the deck amidships.
The two power sources will be interfaced and controlled with a power management system developed by Torqeedo, enabling the fuel cell to be a substantial range extender. The RIB, we are told, will have a run time of five hours, presumably at a cruising speed of around 20 knots, and it has a claimed top speed of about 24 knots. Performance is modest for a 6m RIB, but this is the price paid for the extra weight of its dual energy system, notably a 284kg battery.
The fuel cell within the H2C.
Considering the present viability of supplying the electric cars on the UK’s roads, and the few dockside charging stations that exist along its coast, how realistic is it to supply a hydrogen boat? Well, at the moment not very, but there are some roadside hydrogen refuelling stations in the UK, which a Google search will reveal. Shell are the biggest players in this field, and though predominantly serving larger commercial vehicles, there is no reason why hydrogen cars and thus hydrogen boats should not be making use of this fuel source. The Zephyros project in Holland is currently constructing a hydrogen refuelling dock in the port of Den Helder, just south of the Frisian Islands. In the meantime, H2 Marine Solutions trailer the H2C to a Shell station to fill up with H2.
At the moment Shell is the answer to hydrogen refuelling.
The big question is: where does this hydrogen supply come from? The main source at the moment is what is termed ‘blue hydrogen’. Blue hydrogen is the product of ‘steam reforming’ where hydrogen is produced from natural gas (mainly methane) being heated to around 1000°C in the presence of steam and a nickel catalyst. The end result is carbon monoxide and hydrogen, with the carbon monoxide undergoing further treatment and subsequently producing more hydrogen. The downside is that the end result is the release of various greenhouse gases, which can only be negated by carbon capture. Other forms of fossil fuel can also produce blue hydrogen, but all blue hydrogen processes have some degree of carbon footprint. If the greenhouse gases are not neutralised by carbon capture, the end product is referred to as ‘grey hydrogen’.
The fuel cell produced by UK company Intelligent Energy.
Green hydrogen is a different case altogether. It is produced by electrolysis, otherwise known as ‘water splitting’. Though slightly less efficient than producing blue hydrogen, this system is fast becoming more effective. In simple terms, electricity is used to split water into its component parts of hydrogen and oxygen, and the process does not need to operate above 80°C. Importantly, its primary energy source can be totally renewable, like solar or wind power. At the moment this green fuel source represents a small slice of the hydrogen cake, but it is growing fast.
Various companies, namely De Stille Boot, Intelligent Energy, Hyfly, Koedood Marine Group and Habbeké Shipyard, have all had an input into the H2C project. The Netherlands has had a strong interest in renewables for some time, illustrated by the development of the Zephyr project, which aims to demonstrate the technical viability of a green hydrogen chain in the maritime sector. This project encompasses the entire process from the generation of green power to its application in vessels, with the ultimate goal of net-zero boating.
How does a hydrogen fuel cell work?
A fuel cell is an electrochemical device that combines hydrogen with oxygen to produce electricity, heat and water. The fuel cell is similar to a battery in that an electrochemical reaction occurs as long as fuel is available. Hydrogen is stored in a pressurised container and oxygen is taken from the air. Because of the absence of combustion, there are no harmful emissions, and the only by-product is pure water. So pure is the water emitted from the exhaust you can drink it. Put simply, a fuel cell is electrolysis in reverse, using two electrodes separated by an electrolyte. The anode (negative electrode) receives hydrogen and the cathode (positive electrode) collects oxygen. A catalyst at the anode separates hydrogen into positively charged hydrogen ions and electrons. The oxygen is ionised and migrates across the electrolyte to the anodic compartment, where it combines with hydrogen. A single fuel cell produces less than 1 volt under load, so to obtain higher voltages, many cells need to be connected in series.
Related Posts
