Marine propulsion chat with Udi Erell, founder and CEO of Phoenician Energy.
How did you arrive in your current job role and what are the best and worst aspects?
I went to naval college at the age of 14, so working in the marine industry was always a natural fit for me. I have since spent more than 50 years in touch with the sea. Speaking about my current job, the worst aspect – or should I say the most difficult – is getting investors interested in a new idea. This takes time and it’s what we [at Phoenician] are in the process of doing now for our aluminum-air battery solution. The best aspect is that I get to be involved with very interesting people on a daily basis.
What are the biggest challenges facing the marine industry today?
The biggest challenge is finding alternative fuels for ocean-going vessels. For short-sea journeys, [sailing on] inland waterways and along the coast, we are almost there. In terms of charging infrastructure, there are still problems with local grids [being able to handle this] because charging a vessel is essentially the same as charging 100 Tesla cars all at the same time. I personally don’t believe that lithium-ion is a solution as the energy density [of these batteries] is not enough even for coastal and inland waterways vessels, only for ferries doing relatively short back-and-forth runs.
There are two solutions on the horizon. One is hydrogen fuel cells and the other is what we are doing – the metal-air battery, which is a cross between a battery and a fuel cell.
How is a metal-air battery different to a conventional battery?
The cathode in a conventional battery takes up to 70% of the battery’s weight. The cathode is used as a container for the reactant [e.g. oxygen], usually up to 5% of its weight, that is required for releasing the energy in the metal anode. The result is that most of a conventional battery’s weight is poorly used. A metal-air battery, on the other hand, features an air-electrode that breathes oxygen from ambient air, instead of the conventional cathode. Metal-air batteries therefore have a huge potential for delivering high capacity with low weight.
Tell us about Phoenician’s aluminum-air batteries.
The anode in our case is aluminum. The Al-air technology enables an energy density that surpasses conventional battery technologies, at much lower prices. Furthermore, unlike rechargeable batteries the Al-air battery does not lose charge when not in use and does not degrade over time. It is also inherently safe, with no risk of thermal runaway.
Earlier versions of this technology were plagued by expensive materials for the air cathode and short life. Phoenician’s battery is based on a breakthrough in air membrane technology, which first began development nine years ago. The batteries were used two years ago in land applications, including in an electric Nissan Leaf, which was able to travel over 1,000km [620 miles] using the batteries.
How does the battery system work?
Electrolyte is pumped through the cell, reacting on the air membrane to extract oxygen from the air and attacking the aluminum plates, causing them to release electrons, thus creating electricity. During this process the aluminum is dissolved into the electrolyte, creating aluminum hydroxide. The battery control system regulates the flow to maintain stable power, or starting and stopping, and the whole process is automated.
For marine applications, the batteries are housed in a shipping container. A standard 20ft [6m] container will house around 200 50kWh batteries, giving 10MWh of energy. The electrolyte is in a second 20ft tank container. Together they provide 10 times more energy than an equivalent footprint of lithium-ion batteries. The Al-air battery operates as a generator and can be used to replace the conventional generator on an existing hybrid ship to drive the electric motor. This will greatly extend the vessel’s range, surpassing that of a vessel powered purely by lithium-ion batteries.
Our business model is electricity, so we will sell kilowatt-hours as a service. Consumed containers will be replaced by fresh ones, using common shipping container infrastructure. By the way, the aluminum hydroxide is recyclable.
How has Phoenician achieved this breakthrough and how does it plan to gain commercialization?
The main breakthrough was developing the basic stack of aluminum-air cells and the air-cathode technology. We are currently working on a pilot project for a commercial sea-river vessel, which will travel from the heart of Europe via inland waterways, and then across the North Sea to the UK, and back.
What about the competition?
I will be happy if a competitor devises something similar, as this would convince the market that it is a worthwhile method for providing clean electricity.
Is now the time to make the leap to electric or hybrid propulsion?
A ship is built to last at least 20 years and in the marine sector it is all about business – one has to consider how a vessel will operate within the legislation. Companies that do not care to reduce their carbon footprint will be shut out. Legislation is being gradually introduced all over Europe and the rest of the world, so any owner who is building a ship or intending to operate for the next decade should go electric, or at least hybrid diesel-electric, which will give them the option to eventually replace the diesel generators with innovative alternatives.
