Barca elettrica

Sailing in silence with electricity

From the first submarine to modern ships: electricity moves boats, but there are pros and cons.

by Eni Staff
5 min read
by Eni Staff
5 min read

An idea born more than a century ago

E pensare che l’idea è vecchia tanto quanto la produzione industriale di elettricità, quando nel 12 gennaio 1882 veniva attivata a Londra, la “Holborn Viaduct”, la prima The idea is as old as the industrial production of electricity, when in London on January 12, 1882, the “Holborn Viaduct”, the first thermoelectric power plant in the world, was activated by the Edison Company. A year later (June 28th 1883), thanks to the initiative of professor Giuseppe Colombo and Giovanni Battista Pirelli, his pupil and young promise of industrial engineering, the event was replicated in Milan, a step away from the Duomo, in Via Santa Redegonda…

On September 4, 1882, Thomas Alva Edison inaugurated the second plant in New York, fixing on the entrance gate, a plate with the name of his company: Edison Electric Illuminating Company. His admiration for the great American entrepreneur, made Colombo picking up that surname to found his own company, a name that still persists today. Those first power plants however generated little electricity, just to light up London’s embankment with rudimentary lamps, the Broadway in New York and the arcades of Piazza Duomo in Milan. Or, just enough to recharge the lead batteries of the day, which were heavy and cumbersome but indispensable, especially in the army and navy. Less than five years after the plants opened, on 8 September 1888, the Spaniard Isaac Peral set the first ever proper submarine in the sea. Unfortunately the Spanish navy turned his project down, declaring it useless.

Submarines and electric ships

What, you might ask, have submarines got to do with electricity? Well, everything, because for over a century submarines have to all intents and purposes been fitted with electric motors. It doesn’t matter whether the energy needed is produced by a nuclear generator or a diesel motor and alternator. Wherever it comes from, the energy is used to propel electric motors, which are essential for moving under water, where you have to manage without an exhaust pipe. So, if they were using electricity to navigate in the days of Edison and Colombo, why is it still not widespread in practice? There are many reasons, and they are much the same reasons that electric cars have struggled to take off; after all, the first e-car, the American Baker,  went on the road all the way back in 1899! Let’s look first at the advantages of electric-powered submarines, though, which explain why electric boats are now becoming a reality. According to DNV GL’s records, there are almost 400 electric or hybrid plugin ships – the latter have twin engines, like some cars – in the world today. Ten years ago there were none at all, not counting military submarines, obviously. The most recent addition to the fleet is Ellen, a ferry that sails between the islands Ærø and Als, under the Danish flag. It’s powered by four motors, two with 750 kW and two with 250 kW, fed by a group of lithium batteries with a ca of 4,300 kWh. It has a range of around a hundred miles and can carry 30 cars and 200 passengers.

Pros and cons of electric navigation

Meanwhile, in Japan, they’re building a plethora of little ferries to connect the countless islands in their archipelago. These can carry a few dozen people and a few vehicles. So, the idea of transferring to electric navigation is gaining ground. And little wonder, because it has its advantages, including for the environment. You can install solar panels on an electric ship to charge its batteries, which can also be linked up at harbour to generation systems using a significant proportion of renewable sources, including in Italy. This greatly reduces polluting emissions, in particular of carbon dioxide, in keeping with the International Maritime Organization’s exacting target of halving climate-altering gases from ships around the world by 2050. There are other benefits: electric ships are easier to manoeuvre, because the propellers can change their direction of rotation instantly, and devices on board are simpler and easier to use and maintain. Engines can be optimised more easily based on navigation needs and the ship makes barely any noise, to the benefit of passengers and nature.

Now for the downsides. Foremost is the cost, which is far higher – up to 40% higher – than that of traditionally propelled craft. However, this problem could be significantly reduced as time goes on. The real obstacle is the heaviness and encumbrance of the batteries. It’s been calculated that a medium container ship would need batteries weighing the equivalent of a quarter of their entire carrying capacityTechnical research into making batteries lighter and smaller is still in its infancy overall but has advanced on some fronts. The bulk of innovation in batteries has happened with phones; just think how huge mobile phones were in the early nineties. A third disadvantage: lithium, cobalt, nickel and other essential elements in electric transport can only be found in certain countries and on the sea bed, and the cost of extraction is only going to rise, just like the environmental impact of using these mineral resources. It is difficult to draw conclusions, and at this point we can’t be sure whether the pros will overcome the cons.