Electric boat

This article is about electrically powered boats in general. For the company called "Electric Boat", see General Dynamics Electric Boat.
In 2012, PlanetSolar became the first ever solar electric vehicle to circumnavigate the globe.
A passenger solar boat Solifleur by MW-Line, Switzerland, 1995.

While a significant majority of water vessels are powered by diesel engines, with sail power and gasoline engines also remaining popular, boats powered by electricity have been used for over 120 years. Electric boats were very popular from the 1880s[1] until the 1920s, when the internal combustion engine took dominance. Since the energy crises of the 1970s, interest in this quiet and potentially renewable marine energy source has been increasing steadily again, especially as solar cells became available, for the first time making possible motorboats with an infinite range like sailboats. The first practical solar boat was probably constructed in 1975 in England.[2]

History

Early

Moritz von Jacobi, inventor of an early electric boat.

An early electric boat was developed by the German inventor Moritz von Jacobi in 1839 in St Petersburg, Russia. It was a 24-foot (7.3 m) boat which carried 14 passengers at 3 mph. It was successfully demonstrated to Emperor Nicholas I of Russia on the Neva River.

Golden Age

It took more than 30 years of battery and motor development before the electric boat became a practical proposition. This method of propulsion enjoyed something of a golden age from about 1880 to 1920, when gasoline-powered outboard motors became the dominant method.

Gustave Trouvé, French electrical engineer, patented a small electric motor in 1880. He initially suggested that the motor could power a set of paddle wheels to propel boats on the water, and later argued for the use of a propeller, instead.

Electric motor designed by Immisch & Co., who established the first fleet of electric launches in London.

An Austrian emigre to Britain, Anthony Reckenzaun, was instrumental in the development of the first practical electric boats. While working as an engineer for the Electrical Power Storage Company, he undertook much original and pioneering work on various forms of electric traction. In 1882 he designed the first significant electric launch driven by storage batteries, and named the boat Electricity.[3] The boat had a steel hull and was over 7 metres long. The batteries and electric equipment were concealed from view underneath the seating area, increasing the passenger accommodation. The boats were used for leisure excursions up and down the River Thames and provided a very smooth, clean and quiet trip. The boat could run for six hours and operate at an average speed of 8 miles per hour.[4]

Moritz Immisch established his company in 1882 in partnership with William Keppel, 7th Earl of Albemarle, specializing in the application of electric motors to transportation. The company employed Magnus Volk as a manager in the development of their electric launch department. After 12 months of experimental work starting in 1888 with a randan skiff, the firm commissioned the construction of hulls which they equipped with electrical apparatus. The world's first fleet of electric launches for hire, with a chain of electrical charging stations, was established along the River Thames in the 1880s. An 1893 pleasure map of the Thames shows 8 "charging stations for electric launches" between Kew (Strand-on-the-Green) and Reading (Caversham).[1] The company built its headquarters on the island called Platt's Eyot.

From 1889 until just before the First World War the boating season and regattas saw the silent electric boats plying their way up and downstream.[5]

Early electric launch on the River Thames, built by William Sargeant.

The company's electric launches were widely used by the rich as a conveyance along the river. Grand ships were constructed of teak or mahogany and furnished luxuriously, with stained glass windows, silk curtains and velvet cushions. William Sargeant was commissioned by Immisch's company to build the Mary Gordon in 1898 for Leeds City Council for use on the Roundhay Park Lake - the boat still survives and is currently being restored.[6] This 70 foot long luxury pleasure craft could carry up to 75 passengers in comfort. Launches were exported elsewhere - they were used in the Lake District and all over the world.

In the 1893 Chicago World Fair 55 launches developed from Anthony Reckenzaun's work carried more than a million passengers.[7][8] Electric boats had an early period of popularity between around 1890 and 1920, before the emergence of the internal combustion engine drove them out of most applications.

Most of the electric boats of this era were small passenger boats on non-tidal waters at a time when the only power alternative was steam.

Decline

An electric passenger launch on Lake Königssee in Germany

With the advent of the gasoline-powered outboard motor, the use of electric power on boats declined from the 1920s. However, in a few situations, the use of electric boats has persisted from the early 20th century to the present day. One of these is on the Königssee lake, near Berchtesgaden in south-eastern Germany. Here the lake is considered so environmentally sensitive that steam and motor boats have been prohibited since 1909. Instead the Bayerische Seenschifffahrt company and its predecessors have operated a fleet of electric launches to provide a public passenger service on the lake.[9][10][11]

The first electrically powered submarines were built in the 1890s.[12] Since then, electric power has been used almost exclusively for the powering of submarines underwater, although diesel was used for powering them on the surface until the development of diesel-electric transmission by the US Navy in 1928.

The use of combined fuel and electric propulsion has gradually been extended over the years to the extent that some modern liners such as the Queen Mary 2 use only electric motors, powered by diesel and gas turbine engines. The advantages include being able to run the fuel engines at an optimal speed at all times and being able to mount the electric motor in a pod which may be rotated by 360° for increased manoeuvrability.

The use of electricity alone to power boats stagnated apart from their outboard use as trolling motors until the Duffy Electric Boat Company of California started mass-producing small electric craft in 1968. Duffy Boats has produced over 10,000 electric powered boats to date and is producing well over 300 per year today. It wasn't until the 1980s that the Electric Boat Association was formed and solar powered boats started to emerge.

Components

The main components of the drive system of any electrically powered boat are similar in all cases, and similar to the options available for any electric vehicle.

Charger

Electric energy has to be obtained for the battery bank from some source.

Solar panels deployed on a small yacht at sea.

In all cases, a charge regulator is needed. This ensures that the batteries are charged at the maximum rate that they safely can stand when the power is available. It also ensures that they are not overcharged when nearing full charge and not overheated when a large charge current becomes available.

Battery bank

Example of a modern production electric boat.
SB Collinda, the first solar powered boat to cross the English Channel, seen here in Bristol Harbour.

There have been significant technical advances in battery technology in recent years, and more are to be expected in the future.

The size of the battery bank determines the range of the boat under electric power. The speed at which the boat is motored also affects range – a lower speed can make a big difference to the energy required to move a hull. Other factors that affect range include sea-state, windage and any charge that can be reclaimed while under way, for example by solar panels in full sun. A wind turbine in a good following wind will help, and motor-sailing in any wind could do so even more.

Speed controller

To make the boat usable and maneuverable, a simple-to-operate forward/stop/backwards speed controller is needed. This must be efficient—i.e. it must not get hot and waste energy at any speed—and it must be able to stand the full current that could conceivably flow under any full-load condition. One of the most common types of speed controllers uses pulse-width modulation (PWM). PWM controllers send high frequency pulses of power to the motor(s). As more power is needed the pulses become longer in duration.

Electric motor

A wide variety of electric motor technologies are in use. Traditional field-wound DC motors were and still are used. Today many boats use lightweight permanent magnet DC motors. The advantage of both types is that while the speed can be controlled electronically, this is not a requirement. Some boats use AC motors or permanent magnet brushless motors. The advantages of these are the lack of commutators which can wear out or fail and the often lower currents allowing thinner cables; the disadvantages are the total reliance on the required electronic controllers and the usually high voltages which require a high standard of insulation.

An example of an electric retrofit. Two 9kW LMC motors powered by 16, Interstate deep-cycle 6Volt batteries.

Drive train

Traditional boats use an inboard motor powering a propeller though a propeller shaft complete with bearings and seals. Often a gear reduction is incorporated in order to be able to use a larger more efficient propeller. This can be a traditional gear box, coaxial planetary gears or a transmission with belts or chains. Because of the inevitable loss associated with gearing, many drives eliminate it by using slow high-torque motors. The electric motor can be encapsulated into a pod with the propeller and fixed outside the hull (saildrive) or on an outboard fixture (outboard motor).

Types

There are as many types of electric boat as there are boats with any other method of propulsion, but some types are significant for various reasons.

RA66 Helio is a solar-powered 20m-catamaran cruising on the Untersee, a part of Lake Constance. It is based in Radolfzell, Germany.
An example of an old idea re-birthed. In 2014, the first electric retrofit of its kind was performed on a 1973 Tollycraft 30' Sedan Cruiser. The vessel was originally powered by two (2) Chrysler 318 V8's accompanied by two (2) 80 gallon fuel tanks. The conversion took place in Vancouver, Canada and the vessel (e-Tolly) is now powered by two 9kW LMC motors with energy supplied by 16, Interstate deep-cycle 6Volt batteries. Maximum Endurance 13hrs. Maximum Speed 10 knots.

Wired electric boats

The electric ferry Steffi on the Straussee, 30 km east of Berlin.

A special category of electric boats are the vessels receiving their electrical power by wire. One or two wires are fixed over the water and the boat can make contact with them to draw electric current. In case of a single wire the electrical circuit has to be closed by the water itself, giving rise to a larger resistance and corrosion of the electrodes. In case of two wires no electric current has to be sent through the water, but the twin wires, which cause a short-circuit whenever they come into contact with each other, complicate the construction.

Naturally the boat has to stay close to the wire and therefore it is limited in its maneuverability. For ferries and on narrow canals this is no problem. The Straussee Ferry in Strausberg, Germany is an example. It crosses a lake along a 370 m trajectory. It is powered by 170 V from a single overhead wire. In the Mauvages tunnel on the Marne-Rhine Canal a bipolar overhead line provides 600 V DC to an electrical tug, pulling itself and several ships through the 4877 m tunnel along a submerged chain. This prevents the buildup of diesel exhaust fumes in the tunnel. Another example was the experimental electrical tug Teltow on the Kleinmachnower See, 17 km south-west of Berlin. It was used from 1903 till 1910 and had current collection poles based on those used on trolley buses.

Pollution and embodied energy

Further information: Embodied energy

All the component parts of any boat have to be manufactured and will eventually have to be disposed of. Some pollution and use of other energy sources are inevitable during these stages of the boat's life and electric boats are no exception. The benefits to the global environment that are achieved by the use of electric propulsion are manifested during the working life of the boat, which can be many years. These benefits are also most directly felt in the sensitive and very beautiful environments in which such a boat is used.

The May 2010 edition of Classic Boat magazine carried a pro and con article entitled Electric debate.[24] Jamie Campbell argued against electric boating on four main counts, which were rebuffed by Kevin Desmond and Ian Rutter of the Electric Boat Association. Jamie Campbell asserted that electric propulsion can no more be justified afloat than a Seagull outboard motor, proposing wooden sailing boats and rowing dinghies as "by far the most environmentally sensitive and renewable options for recreational boating".

Electricity production
Campbell asserts that the lack of pollution from an electric boat "reeks of nimbyism" as "the discharge is all in someone else's back yard" and that the provision of re-charging points may involve digging up miles of habitat. Desmond responds that while there is no doubt that rechargeable batteries derive their energy from power stations (when not charged on board by solar and wind generation), noisier internal-combustion-engined boats obtain their fuel from even further away and that, once installed a power cable is less environmentally disruptive than a petrol station. Rutter notes that electric boats tend to recharge overnight, using 'base load'.
Efficiency
While there are losses in the charge/discharge cycle and in the conversion of electricity to motive power, Rutter points out that most electric boats need only about 1.5 kW or 2 hp to cruise at 5 mph, a common maximum river speed and that a 30 hp petrol or diesel engine producing only 2 hp is considerably more inefficient. While Campbell refers to heavy batteries requiring a "load-bearing hull" and "cranky, even unseaworthy vessels", Desmond points out that electric boaters tend to prefer efficient, low-wash hull forms that are more friendly to river banks.
Pollution
Campbell discusses the pollution that "traditional" batteries put into the water when a boat sinks, but Desmond says that electric boats are no more liable to sinking than other types and lists the leakage of fuel, engine oil and coolant additives as inevitable when an internal-combustion-engined boat sinks. Rutter points to the "very nasty cocktail of pollutants" that come out of a diesel wet exhaust in normal use.
Battery manufacture
Campbell mentions "all manner of noxious chemicals ... involved in battery manufacture", but Rutter describes them as being "lead and sulphuric acid with a few extra trace metals in a modest plastic box" with a potential lifetime of 10–12 years. Desmond says that the US has a 98% recycling rate for lead acid batteries and that the battery and lead-smelting industries observe some of the tightest pollution control standards in the world.

The article mentions 25% and 30% discounts being offered to electric boaters by the UK Environment Agency and the Broads Authority and that battery powered vehicles have 35 the carbon footprint of their petrol equivalents. It is claimed that a typical recharge after a day's cruising costs £1.50, without the use of solar or wind power.[24]

Solar ships

PlanetSolar, the world's largest solar-powered boat and the first ever solar electric vehicle to circumnavigate the globe (in 2012).

In 2010, the Tûranor PlanetSolar, a 35 metre long, 26 metre wide catamaran yacht powered by 537 square metres of solar panels, was unveiled. On 4 May 2012 it completed a 60,023 kilometres (37,297 mi) circumnavigation of the Earth in Monaco after 585 days and visiting 28 different countries, without using any fossil fuel. It is so far the largest solar-powered boat ever built.[25]

India's first solar ferry, a 75 passenger boat fully powered by sun, is under construction. It is expected to completed by the middle of 2016.[26]

Japan's biggest shipping line Nippon Yusen and Nippon Oil Corporation said solar panels capable of generating 40 kilowatts of electricity would be placed on top of a 60,000 tonne car carrier ship to be used by Toyota Motor Corporation.[27][28][29]

The Monaco yacht company Wally has announced a "gigayacht" designed for billionaires torn between buying a mansion and a superyacht.[30] The Why 58 x 38 is designed to have an autonomous cruising range of 12,000 miles at 12 knots by means of 900m2 of solar panels which generate 150 kW to assist the diesel-electric motors and optional Skysails.[31]

See also

References

  1. 1 2 The Oarsman's and Angler's Map of the River Thames from its source to London Bridge (1991. Old House Books, Devon ed.). James Reynolds & Son, London. 1893.
  2. Electrical Review Vol 201 No 7 12 August 1977
  3. Illustrated with wood engravings in the Electrical Review, Vol.XI, No.255, 14 October 1882, pp.296 and 297
  4. "Batteries". Mary Gordon Trust.
  5. 'Electric Boats on the Thames 1889-1914' by Edward Hawthorne, 1995 Alan Sutton Publishing Ltd; ISBN 0-7509-1015-1 : many references to Moritz Immisch's pioneering work with electric boats on pages 14-29; pages 30-40; pages 149-150, 166-169, and certain other pages
  6. "Mary Gordon Electric River Boat". Retrieved 31 May 2010.
  7. "The story of solar powered boats". Retrieved 31 May 2010.
  8. "History of our Classic Motor Yachts". Elco. Retrieved 21 February 2011.
  9. "Bayerische Seenschifffahrt GmbH" [Bavarian Lakes Maritime Ltd.] (in German). Bavarian State Ministry of the Interior. Retrieved 11 July 2011.
  10. "Geschichtliche Hintergründe" [Historical Background] (in German). Bayerische Seenschifffahrt. Retrieved 11 July 2011.
  11. Quiet Cruising on Königssee Archive
  12. "General Dynamics Corporation", Encyclopædia Britannica (15th ed.), 1993
  13. Stensvold, Tore. "Denne fergen er revolusjonerende. Men passasjerene merker det knapt" Teknisk Ukeblad, 20 March 2015.
  14. Stensvold, Tore. "Nå lader batterifergen mer enn hun trenger" Teknisk Ukeblad, 13 May 2015.
  15. Setting a Course for Carbon-Free Shipping 2014 archive. Video on YouTube
  16. Stensvold, Tore. "Lønnsomt å bytte ut 70 prosent av fergene med batteri- eller hybridferger" Teknisk Ukeblad, 14. august 2015. In English
  17. Electric ferry jolts discussion over powering ships in B.C. Vancouver Sun
  18. Sweden launches world's first quick-charging electric passenger ferry GizMag
  19. Electric drive train by Visedo to equip world’s largest electric ferry
  20. Valle, Marius. "Dette er Norges første fiskebåt med elmotor" Teknisk Ukeblad, 31 July 2015.
  21. "Solarschiffe für die Expo?". Umwelteinsatz.ch. Retrieved 20 June 2009.
  22. "The world's first crossing of the Atlantic on a solar boat". transatlantic21. Retrieved 20 June 2009.
  23. "EERE News: EERE Network News - 06 December 2006". Apps1.eere.energy.gov. 6 December 2006. Retrieved 20 June 2009.
  24. 1 2 Campbell, Jamie; Kevin Desmond; Ian Rutter (May 2010). "Electric debate". Classic Boat (Croydon, England: IPC Media) (263): 48–49. ISSN 0950-3315. Retrieved 13 April 2010.
  25. Raphael Domjan the swiss ecoexplorer was the founder and the expedition leader of the project PlanetSolar. "MS Tûranor PlanetSolar yacht completes her first tour around the world with a success". Charterworld.com. 4 May 2012. Retrieved 9 May 2012.
  26. "India’s First 75-Seater Solar Ferry Readies To Test The Waters". OfficeChai. Retrieved 2016-02-04.
  27. "Alternative Energy and Fuel News: ENN - Know Your Environment". ENN. 26 August 2008. Retrieved 20 June 2009.
  28. "Japan launches first solar cargo ship". Solardaily.com. Retrieved 20 June 2009.
  29. "Solar ship sails the ocean green - National". www.smh.com.au. 15 March 2005. Retrieved 20 June 2009.
  30. "The world's first gigayacht". Motor Boat Monthly. 11 June 2010.
  31. "Why". Wally Yachts. Retrieved 11 June 2010.

External links

This article is issued from Wikipedia - version of the Saturday, March 05, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.