Electric boat

An electric boat is a motorboat that is electrically powered. This is usually done by electrical energy is charged from the power grid with a charger in an accumulator. Most of which can be supplied to an associated electric motor with a propeller during the ride. A solar boat is a particular type of electrical boots, in which the energy is mainly supplied by on-board solar cells.

• 2.1 Energy Source
• 2.2 Battery
• 2.3 Electric motor
• 2.4 generating propulsion

• 3.1 Motor Boats in classic style

History

The first viable electric boat

The first successful experiments with an electric boat drive were carried out on 13 September 1839 by Moritz Hermann von Jacobi with a converted rowing boat. It was thus the first viable electric boat in the world. Another test drive took Jacobi in the following years, with an optimized from him DC motor and improved galvanic cells by William Grove. Further technical improvements to the electric drive motor, conducted by Jacobi in the following years have made ​​it necessary in October 1841 more rides.

Further development

As part of the further history was conducted in 1886 with the Electra targeted testing trips on the Spree to solve the transport problem in Berlin, but this form could not prevail.

It was not until the energy crisis of the 1970s was renewed interest in this form of transportation on the water, because it was technologically possible to charge batteries using solar cells electrically. With these solar boats it was first possible to simultaneously achieve both theoretically unlimited range like sailboats, but also a maneuverability like motor boats. The first practically usable solar boat was probably constructed in 1975 in England.

Components

As all vehicles need electric boats for the required energy is a primary source, a storage capability, and a conversion into mechanical propulsion, generally electric motors and propellers or impellers.

Energy source

• For most electric boats, the batteries are charged by charger on shore-side electricity network. The environmental performance of such electric boats is in the low direct noise and pollutant emissions of the boat itself, but depends indirectly on purchased electricity mix. Efficiency and environmental performance of a thermal power plant are better than individual combustion engines in general. Electrical charging options are common in marinas. In some areas, they are found in harbors and landing places for tourists.

• Wind generators are common in sailing yachts. They are like the drag - generators in high winds on the way useful, but a lot more at idle periods in port or at anchor. With the usual sizes, however, it is at best auxiliary drives. There are some yachts with such large wind turbines that they represent the main drive. However, they work purely mechanical; there are no primary wind -powered electric boats known. Larger wind turbines set on a small boat a difficult to solve security problem,

• Solar cells can be installed on existing or specially constructed surfaces. Most solar boats have horizontal solar roofs, as these are relatively resistant even against strong winds. However, can deliver more power and adjustable surfaces are essential if solar boats in winter are to be operated in northern latitudes the sun inclined toward a surface. The size of the solar surface determines performance and range. Solar boats with relatively large solar usable land in good conditions reach their cruising speed without power from the battery to take, or it can carry and charge the battery. Such boats can make even on cloudy days ride without using the battery and have thus mostly an unlimited range.

• Towing generators are common in sailing yachts, travel the long distances. In strong winds will be sailed close to the hull speed. The additional resistance of the generator then is hardly noticeable. During calm periods the energy thus stored can be used in eingeholtem towing generator again. Some boats used instead of a towed generator normal propeller and the electric motor boat in this manner. However, in a conventional propeller wings for generator operation are the wrong way round.

• Heat engines can be used with generators, for generating electrical energy. Diesel-electric drives without electrical energy storage are used in large ships. However, they are not counted as electric vehicles, since no operation is possible without a combustion engine. With electrical energy storage of this mixing drive is called a hybrid drive. Well-known representatives are conventional military submarines. In shipping are basically two types used: In the series hybrid generator with a small internal combustion engine or Stirling engine charges the battery. The boat is driven solely by the electric motor.
• The parallel hybrid, both the engine and the electric motor acting on the drive shaft and can also be used independently. During operation of the internal combustion engine, the electric motor may act as a generator and charges the battery. The waste heat of the engine can be used by the heat exchanger for the heating or cooking of hot water.

• Fuel cells found in 2003 by German U- boats of the 212 A class for the dive trip application. A prototype for the combination of photovoltaic and reversible hydrogen -powered fuel cells, which " Solgenia ", is being developed as a research vessel at the University of Konstanz and used since the beginning of 2007 on Lake Constance in practical operation.

Battery

As with land vehicles, boats, the battery is also in the component that most limits the characteristics of the vehicle because the energy density in comparison to the chemical energy storage is smaller. At least for the slow displacement of the boot, however, is less than is given by the weight due to the cost, especially since all the electrochemical batteries have a very limited service life.

For small drives lead-acid or lead -gel batteries are still common, but very quickly arrive by the sluggish ion exchange on their performance limit and overload have short lifetimes.

The size of the battery determines more than any other component of the utility of the electric or solar boat. A large battery allows a decent range at low speeds; on a single charge than 200 km have already been achieved. Extreme solar boats have no or only a very small battery.

Pleasure boats are usually equipped with an accumulator that is sufficient for a day trip. On the other hand, for example in a Kajüt electric boat on the Chiemsee with 8 Lead - gel batteries Sehmataler of the German manufacturer cordless power ranges of up to about 200 km at 6 km / h (corresponding to a travel time of about 30 hours). The chemical durability of the manufacturer about 12 years or 700 charging cycles.

Electric motor

The electric motor is a component of each electric boat. In addition to the Inbordmotoren any design is available for small boats a wide range of outboards. In order to maneuver the boat is at least a forward and reverse switch necessary, best with a few steps. Today, electronic controllers are common to permit gradual adaptation to the lowest speed. Such boats are very easy to drive. Modern controllers allow a 4- quadrant operation, ie driving and braking are both forward and backward possible. Usually, however, held back by driving in reverse position. High-performance engines are usually inboard AC motors ( asynchronous or synchronous ) with dual-circuit water cooling. The motor controller converts the coming of lithium batteries and / or supercapacitors direct current into three-phase order according to the specification from the accelerator. So you can also use steering drives ( Z- drives), there are also high-speed engines to about 5000 1/min in the vibration class S1. With these drives, multi-engine luxury yachts can sail on waters where there is a ban on burning drives. This drive concept was elaborated by Boat Shop Rust in cooperation with Aquamot and are therefore also speeds of over 100 km / h is not more utopian. The advantage of this technology is the extremely high torque, there are acceleration values ​​obtained can not be reached by much more powerful internal combustion engines. The acceleration ramp must be programmed even flatter to the mechanics not to overload.

Generating propulsion

The propeller is the modern boot drive per se, although paddle wheels are possible which have their advantages during acceleration and braking. In order to obtain a satisfactory range, electric boats at a particularly high efficiency is required. Therefore, rather large, slowly rotating propellers are used, but a compromise with the performance characteristics must be found, especially with respect to depth and vulnerability on seagrass. The required low speeds can only be achieved with special motors, especially large motors or gearboxes.

The magneto hydrodynamic drive has been realized only as a prototype and research.

Types

• Historic Electric boats are popular especially in the United Kingdom ..

• Electric boats for inland waters: many canals, rivers and lakes are relatively small and sheltered and often have speed limits. On some waters are electric boats are the only approved motor boat types. Due to the low energy density of electric boats are not suitable for applications with durable high power requirement ( for example, continuous high speeds or long drives against current, wind and weather).

• Motor Boats in a classic style that reach surface speeds with lithium battery and powerful electric motors.

• Electric Outboard: The available mass-produced electric outboard motors for smaller boats have because of the small, rapidly rotating propeller rather poor efficiency, but are mature. Some outboards manufactured in small series or as prototypes have higher efficiencies and are suitable for pleasure boats. The life of some types is insufficient without intensive maintenance for professional use, such as ferries.

• Sailing yachts have now almost always an auxiliary motor. There are two main uses, such as a slowdown slide and on the other to maneuver in harbors or narrow driveways. For both purposes can provide good services, an electric drive, because when driving slowly during calm very little power is needed and it can be driven with a small battery for a long time. Harbor maneuvers, however, usually last a few minutes and even small electric motors can provide greater benefits during this time and are very finely adjustable.

• Using hybrid boats, as described above, usually a combustion engine and an electric motor. For small or particularly low-drag boats instead and muscle power drives have proved successful.

• Solar boats. Photovoltaics is also used in boats. Unlike solar electric boats boats use the direct solar radiation as an energy source. However, there is a continuous transition between pure electric boats and pure solar boats. There are extreme solar boats without a battery for record purposes, those with a very small battery for racing purposes, use solar boats for travel purposes and pleasure boats with little solar cells that can cover the consumption at the weekend about when they can charge the battery in the summer during the week. More details and references see solar vehicle.

• Catenary ferries draw their energy from an overhead line similar to O buses.

• Electrically operated chain ships to be used today in France for a long time poorly ventilated tunnel to deal with.

• Most submarines go in submerged electric, civilian submarines usually even purely electric.

Motor Boats in classic style

• This is known electric motor-driven, open, small motor boats with classic form of the hull as " electric runabout ". You can transport up to about eight people. The performances are already sufficient for the operation of other water sports. For example, the water-skiing in the wake of an electric runabouts possible.

• Design goals:

In contrast to previous electric boats, the design goal of an electric runabouts is to achieve the maximum degree of driving fun. Fun - maximization: The maximum driving fun than design goal is achieved through special focus on the portions of drive engineering, hydrodynamics and aerodynamics (? ). In particular, the drive technology currently offers great strides in electric motor concepts. Weight minimization: The total mass of an electric runabouts crucially depends on its energy needs. This requires a further design goal. The minimization of the total mass. To meet the driving pleasure, the overarching goal must be the ( above mentioned ) other areas ( hydrodynamics, aerodynamics) are optimized.

• Technical details: Drive technology: The design of the electric runabouts is a high performance of the accumulator - expected cells. Based on lithium technology cells provide the necessary performance.
• Energy Storage: Energy storage serve the electric runabout accumulators. They are placed in several units (so-called battery cells) at appropriate places on board the boats. Depending on the energy needs of the boat determines the size and number of battery cells.
• Propulsion: Propulsion come as both all common - as well as Unusual into consideration.
• Fluid Mechanics: An optimization of the flow conditions is done with the analysis of the existing flow along the boat.
• Hydrodynamics: Hydrodynamics is optimal when the resistance of the boat is minimized with respect to the water.
• Aerodynamics: The aerodynamics is optimal when the resistance of the boat with respect to the air is minimized.