FR2484356A1 - Electrically propelled boat using solar panels and accumulators - has solar panels placed on upper surface of boat to recharge accumulators which drive propeller - Google Patents

Abstract

The boat is propelled by an electric motor, powered from accumulators which are charged by photovoltaic solar panels mounted on the boat superstructure. The boat hull (18) is designed for minimal drag within the speed range of 3 to 7 knots, with particular care taken in the shape and finishing of the surface to ensure laminar water flow around the hull. The solar panels (20,23) are mounted horizontally on the uppermost horizontal surfaces of the boat, partic. on the roof (21) covering the cockpit and on the fore-deck (19). Facilities to orient the solar panels towards the sun may be incorporated. The solar panels generate an electric potential which is used to charge accumulators which drive the electric motor coupled to the boats propeller (17).

Description

Technical area.

 The present invention relates to a propulsion boat powered by an electric motor powered by live photovoltaic cells, or by the addition of accumulator batteries, in buffer, recharged themselves by the photovoltaic cells.

Problem.

 It involves using solar energy by photovoltaic cells for the propulsion of boats, device, which, apart from the initial investment required, ensures free energy, non-polluting, quiet, reliable and clean.

 However, the energy collected is low and to use it well, it is necessary to collect as much as possible, and not to waste it by carefully studying the forms of hulls best adapted, as well as the necessary and important dimensions of the panels to ensure the propulsion of the ship in the best conditions.

State of the art and disadvantages.

In the current state of the art, solar cell panels provide good sunlight in the south of France, a power of 90 W m2G
It is therefore necessary to adapt this rather low power to the conditions of use for the propulsion of ships in two ways.

1) increase the energy received by multiplying the exposed surface.

2) adapting the shapes of the ship to maximum efficiency for a given speed and propulsive power.

 Indeed, such a low power can hardly be used for the propulsion of a normal and conventional boat, without providing special provisions to be able to have large areas of panels and also, to be able to accumulate energy in the moments of non-operation, and so be able to return when you need it.

 In pleasure boating, fishing boats or boardwalks have an engine that generally runs very little during the day since the boat is mostly used to get to a place not far from the harbor, to Anchor to spend the most enjoyable hours of the day and then return to the port, or to join another at short distance (small coastal cruise).

 The low power of current solar batteries would not allow continuous use (more than 5 to 7 hours in the best cases). That's why there are no such boats now.

 The present invention is intended to overcome these disadvantages to allow the practical use of solar energy for the propulsion of boats intended for the use which has just been mentioned.

EXPOSED OF THE INVENTION

 The boat is mainly characterized by the combination of a) a hull providing the minimum resistance to washing both in calm waters and in the chop, and that depending on the load, ie a hull having a maximum coefficient of fineness, a minimum drag, an important coefficient of penetration for speeds of 3 to 7 knots, and little rolling, thanks to a great stability of shape ensuring a laminar flow of water streams for the expected speed, (b) solar panels to transmit electricity to the largest possible area, distributed in the superstructure of the vessel away from water projections (as far as possible even though they are waterproof).

 The panels are arranged on the available surface of the boat, that is to say on the beach before and above the cockpit, the deckhouse or the awning. In order to increase the surface area, additional overlapping panels are provided at rest at the fixed panels on the front beach and on the roof or deckhouse and which can be deployed on the fly and at the moments when it is desired to capture the maximum of solar energy, that is to say when stopped, when you want to recharge the batteries.

 The folding of the additional panels can be done either on top of each other, in the manner of a screen, or by sliding one under the other using slides.

 An elegant solution consists in providing fixed panels at the level of the gangways and in having deployable movable panels articulated around vertical axes at the front of the boat, arranged in slots under the gangways and being able to offset laterally in the manner of the wings of the boat. aircraft with variable geometry.

Solution to the problemj benefits and industrial result
The various provisions allow to use large surraces of photovoltaic cell panels and to be able to capture the maximum energy. This energy is stored partially in accumulator batteries from which it can be drawn with sufficient intensity
to ensure propulsion.

 Deployment of additional panels is possible when space is available, which is not the case in ports. However, in these, the fixed panels are sufficient to recharge the battery since the boat spends most of her time docking at the dock.

 The device is applicable on fishing boats and board of various sizes. The hulls used are designed to have the least amount of resistance to advance and use only reduced powers compared to normal. An elegant solution is to use multihulls: catamarans or trimarans that have a great stability of shape and a minimum resistance to the progress.

 It is also possible to use boats with a classic hull but with a Norwegian-style bow and water stern (canoe, "pointed", "pinasse", and ...) to ensure a laminar flow of water along the water. the hull with a minimum of swirl and waves back.

 Thanks to the device of the invention, a motor boat is moved with a free and non-polluting energy, the operation being carried out silently reliably and with maximum cleanliness. This kind of boat can therefore be used not only at sea but in inland waters, on drinking water retention lakes, for example.

 The invention will be better understood using the attached description which gives some non-limiting examples of practical realization and which are illustrated by the drawings Joints.

Brief description of the figures.

In said drawings
Figure 1 is a schematic overview of the boat propulsion device of the invention.

 Figure 2 is a simplified elevational view of a monohull boat using photo voltaic cells according to the invention.

 Figure 3 is a plan view of the boat shown in Figure 2 showing how photovoltaic cell panels can expand to capture more energy.

 FIG. 4 is a side view of a catamaran boat according to the invention showing, on its left side, the development of photovoltaic cell panels by horizontal slides and, in its right part, the development of photovoltaic cells panels by opening of panels articulated around an axis, like a book.

 Figure 5 is a plan view of a third type of boat having additional panels hinged about vertical axes at the front and departing laterally from the wing material of variable geometry aircraft.

 Figure 6 is another variant of panels folded accordion or folding.

 Figure 7 is a view of the panels of Figure 6 deployed to capture solar energy.

Description of some embodiments0
The principle of the mode of propulsion of boats is shown in Figure 1 where the sun 1 insole by its spokes 2 and 3 photovoltaic cells panels 4 and 5. The panels 4 and 5 emit a direct current and their negative poles are connected to the conductor 6 while their positive poles are connected to the conductor 7. Separating diodes 8> 9 respectively between the panels 4 and 5 and the conductor 7, have a valve function for
let the current flow in one direction only. The conductors 6 and 7 are connected to the buffer battery 10 via a charge controller 11 whose technique is sufficiently known not to be described here.

The current emitted by the panels 4 and 5 and / or the buffer battery 10 is applied by the conductors 6 and 12 to the control cabinet 13 which modulates the direct current and may optionally reverse it in the conductors 14 and 15 which supply the power. 16 ~ motor actuating the propeller 17 at the speed and in the desired direction.

 The following is a method of approximating the power supplied.

 If the bridge plan fits into a rectangle whose area is Length x Width and the deck area is "Sp" (Bridge) while "Sr" (Rectangle) is the surface of the circumscribed rectangle - to have the maximum Sp exposed surface must tend towards Sr. It seems that the limit for monohulls is around 0.7 to 0.85 (hence the interest of catamaran or trimaran multihulls).

Sp = (0.7 to 0.85) of Sr.

- the average surface area available for the panels is in the ratio of
1/2 Surface of the rectangle (Length x width of the boat) @ 2
So L x 1: 2 = m2 of solar panels
Captured power (in peak) = m2 x 90 W = P. picked up.

Captured power x efficiency (0.50 to 0.60) = Power supplied to the propeller, or propulsive power.

Example: a boat 10 m long and 3.60 m wide can capture about 10 m x 3.60: 2 x 60 W = 1 kW, 620 (power crete) power quite low.

Hence the interest of the deployment of the exposed surface.

The table below shows the applications of "solar powers" to different boat sizes

<tb> Length <SEP> to <SEP> Surface <SEP> of <SEP> Power <SEP> Speed <SEP> Displays
<tb> the <SEP> flot- <SEP> panels <SEP> (crete) <SEP> cement
<tb> solar <SEP> tillage
<tb><SEP> 6.10 <SEP> m <SEP> 7.50 <SEP> m2 <SEP> 675 <SEP> W <SEP> 4 <SEP> to <SEP> 5 <SEP> nodes <SEP> 700 <SEP> to <SEP> 1000 <SEP> kg
<tb> 7.65 <SEP> m <SEP> 12.75 <SEP> m2 <SEP> 1147 <SEP> W <SEP> to <SEP> d <SEP><SEP> 5 <SEP> nodes <SEP> 800 <SEP> to <SEP> 1100 <SEP> kg
<tb><SEP> 9.15 <SEP> m <SEP> 19 <SEP> m2 <SEP> 1710 <SEP> W <SEP> 5 <SEP> to <SEP> 5.5 <SEP> nodes <SEP> 1T500 <SEP> to <SEP> 2T
<tb> 12.20 <SEP> m <SEP> 30 <SEP> m2 <SEP> 2700 <SEP> W <SEP> 5.5 <SEP> nodes <SEP> 4T <SEP> to <SEP> 6T
<tb> 15.50 <SEP> m <SEP> 51 <SEP> m2 <SEP> 4567 <SEP> W <SEP> 5.6 <SEP> nodes <SEP> 8T <SEP> to <SEP> 12T
<Tb>
Hereinafter, elements relating to the hull are indicated.

 For a better hull we need 1) a prismatic coefficient adapted to the desired speed, 2) a maximum coefficient of fineness, 3) a minimum drag coefficient, 4) a shallow draft, 5) a wet surface the most reduced possible, 6) water lines stretched over a miplate-mirrored hull, 7) a maximum float length compatible with the desired total length, 8) a widest possible deck plan, 9) a wide enough master the well-marked Bouchain shoulders for maximum transverse stability, 10) the hull is designed and calculated for a given speed, less than the critical speed in displacement.

 The following three factors of resistance to progress are indicated below.

1) The speed coefficient "C" is the ratio of the speed
flotation on the square root of the length

<tb> C <SEP> ~ <SEP> V <SEP> nodes
<tb><SEP> v <SEP>, 26
<Tb>
C will vary from 1.3 for a small boat of 4 m to 0.8 for a 15 meter boat. The optimal values of C are in the table below.

2) The prismatic coefficient CP will determine the minimum resistance to progress. (Here we find the finesse / drag coefficients and the ratio of the draft and the wet surface). The optimum values as a function of the corresponding optimal desired speeds are summarized in the table below.

<tb><SEP> Coefficient of <SEP> Coefficient <SEP><SEP> Resistance by
<tb> speed <SEP> prismatic <SEP> waves <SEP> and <SEP> moved
<SEP> cement
<tb><SEP> C <SEP> CP <SEP> RW
<tb> (VL <SEP> x <SEP> 3.28 <SEP> x <SEP> C <SEP> = <SEP> Kg <SEP> (strength) <SEP> by <SEP> ton
<tb><SEP> speed)
<tb><SEP> 0.8 <SEP> 0.52 <SEP> 0 <SEP> kg <SEP> 680
<tb><SEP> 1 <SEP> 0.55 <SEP> 1 <SEP> kg <SEP> 360 <SEP> Strength <SEP> by
<tb><SEP> 1,1 <SEP> 0,57 <SEP> 2 <SEP> kg <SEP> 255 <SE>> ton <SEP> from
<tb><SEP> 1,2 <SEP> 0,585 <SEP> 5 <SEP> kg <SEP> 436 <SEP> displacement
<tb><SEP> 1.3 <SEP> 0.60 <SEP> 9 <SEP> kg
<Tb>

Multihulls: C> 1.3 to 1.6
0.50 <CP <0.65
R Very inferior to Table 3) The other important form of drag is R friction resistance.

Rf = wet surface x V1825
0.048
Wet area expressed in m2 = 1.45 x V displacement tonnes x length at the waterline x 3.28
The resistance to advancement is the sum of the resistances = waves and displacement + friction. The propulsive power is equal to the resistance to advancement x the speed.

 We are therefore able, now9, to calculate the power required to operate the boat according to the solar energy received.

Calculation example (1)
A catamaran 4.70 m overall, 4.20 m buoyancy, 75Q kg displacement, for a speed of 5 knots.

What propulsive and practical power does it require? (N overall yield 0.55). C = 1.3 which gives Rw = 9 kg per ton 1) Resistance Rw: 9 kg per ton - here 9 x 0.75 = 6.3 kg
: 6.3 x Speed 5 knots = 31.5 kg.

= 4,66 m2
Rf = = V1,825 x surface mouillée : 100
= 51,825 x 4,65 : 20,5 = 4,29 kg 3) Résistance totale = Rw + Rf = 34,05 + 4,29 = 38,34 kg 4) Equivalence en Watts :@38,34 x 4,98 = 191 W (puissance propulsive) .5) Puissance solaire requise = Puissance propulsive : p
(rendements) (ici 0,55)
= 191 w : 0,55 = 348 soit 350 W environ 6) Si 1m2 de panneaux fournit en crète 90 W, il faudra 350 W : 90 W = 3,86 m2 soit environ 4 m2 de panneaux solaires (soit par exemple 12 panneaux de 1,20 m x 0,30 m).2) Friction resistance Rf:
Wet surface in

= 4.66 m2
Rf = = V1,825 x wet surface: 100
= 51.825 x 4.65: 20.5 = 4.29 kg 3) Total resistance = Rw + Rf = 34.05 + 4.29 = 38.34 kg 4) Equivalence in Watts: @ 38.34 x 4.98 = 191 W (propulsive power) .5) Solar power required = Propulsive power: p
(yields) (here 0.55)
= 191 w: 0.55 = 348 or about 350 W 6) If 1m2 of panels provides 90 W crest, it will require 350 W: 90 W = 3.86 m2 or about 4 m2 of solar panels (ie for example 12 panels of 1.20 mx 0.30 m).

Calculation example (2)
This is a monohull 4.80 m overall, 4.20 m at the waterline, a displacement of 720 kg for a speed of 4, 5 knots.

C = 1.2 for 4 knots, 5 and R = 5.44 kg per ton 1) Rw = 5.44 kg per tonne so here 5.44: 0.720 = 3.92 kg
= 3.92 x 4.5 knots = 17.65 kg 2) Rf - Wet area = 1.45 x 0.72 x 4.2 x 3.28 = 4.58 m2
= 4.51.825 x 4.58: 20.5 = 3.47 kg 3) R. Total = 17.65 + 3.47 = 21.12 kg 4) Equivalence in watts: 21.12 x 4.98 t 105 , 18 W propulsive power or about 106 W 5) Solar power required (0.50 yields) 106 W 0.5 = 212 watts 6) Solar panel area 212 W: 90 = 2.35 a (ie, for example 8 panels of 1.20 mx 0.30) is 2.50 m2.

 We see here that to go from 4 knots 5 to 5 knots, we must go from 2.50 m2 to 4 m2 of solar panels and again with a catamaran. The solar battery surface must therefore be important.

 Referring to FIG. 2, it can be seen that the monohull boat 18 has its front deck 19 covered with solar battery panels 20, whereas the roof or deckhouse 21, at the rear of the windshield 22, is covered with other solar battery panels 23.

 In Figure 3, there is shown a series of solar battery panels 20 and 23 which are deployed around axes such as 24 to open in the manner of a book.

 In the right part of Figure 4, there is shown such panels 25, 26, 27, 28 which open pivoting about axes 29, 30 according to the arrows 31, 32.

In the left part of the same figure, the panels 33, 34 can retract under the panels 35, 36 or slide outwards, in the direction of the arrows 37, 38e This same figure 4 represents a catamaran-type boat of which we recognize the two hulls 39, 40.

 In Figure 5, there is shown a boat in plan with a deckhouse 41 behind the windshield 42 and which is lined with photovoltaic cells on the gangways 43, 44. Additional panels retractable 45, 46, which can slip under the Passways 43, 44 are hinged at the front at 47, 48 and can take the positions which have been shown in solid lines at 46 or dashed lines at 45.

 The articulation system of the photovoltaic panels can vary without departing from the scope of the invention.

 In Figure 4, there is shown a deployment system in the right part and sliding in the left part. In Figure 5 there is shown a hinge retraction system. In Figure 6 there is shown a series of panels 49 to 53 which are connected by lockable hinges such as 54 to 57 so that, deployed, they take the position shown in Figure 7.

 We have seen that a panel of photovoltaic cells of 1 m2 could, in a favorable sunlight, like that which exists in the south of France, produce a power of 90 W. In reality, with the storage efficiencies of the energy in the battery 13, the efficiency of the engine, and other mechanical efficiencies, a panel of one m2 allows to have 65 W and an energy of about 450 W / h per Day. This corresponds to a use of 450 W for one hour or 45 W for ten hours per m2 of photovoltaic cell panels and with a battery 13 of appropriate capacity.

 Floating devices that consume much less energy, such as windsurfing boats but without a sail, can also be used. In this case, for a speed of 4 to 6 knots, the power required is only 95 W and> then, it will not be necessary to provide a buffer battery since panels with an area of 2 to 3 m2 will be sufficient.

 Naturally, the hydrodynamic studies of the boats will have to be pushed to reduce as much as possible the resistance to the advancement. In the case of a monohull, the hull must have round shapes to ensure a better passage in the water with a coefficient of drag lower than a hull with chines. A relatively broad hull is selected from the marten bau and well-arched bouchain shoulders that provide great transverse stability. The water inlet lines at the front are as thin as possible to crack the chop without kicking the waves. A generous freeboard at the front and a fine bow are expected to prevent shocks in the water. The stern has a Norwegian shape to ensure better flow of the water net with minimal drag.

 It goes without saying that the surface of the photovoltaic cell modules depends on the use to be made of the boat, the battery capacities to be charged and the power that one wants to obtain, taking into account the size of the battery. boat.

 Performance will likely be improved in parallel with improving the efficiency of photovoltaic cells.

Claims (6)

 1. Electric motor powered boat powered by accumulator batteries characterized by the combination of: a) a hull 18 providing the minimum resistance to travel both in calm waters and in choppy water, and that depending on the load, that is to say a hull with a maximum coefficient of finesse, a minimum drag, a significant penetration coefficient for speeds of -3 to 7 knots, and rolling little, thanks to a high stability of form providing a laminar flow of water streams for the expected speed, b) panels 4, 5, 20, 23 capturing solar energy to transform it into electricity, with the largest possible surface, distributed in the superstructures of the boat sheltered from calf protests.  2. Boat, as defined in claim 1, wherein the panels 20, 23 are distributed over the beach before and above the cockpit or deckhouse 21 or the awning.  3. Boat, as defined in either of claims 1 or 2, characterized in that additional panels 26, 28, 33, 34, are stackable at rest, at the fixed panels 20, 23, 25, 27, 35, 36, and can be deployed, in operation, or at least in the moments when one wants to capture the maximum of solar energy.  4. A boat as defined in either one of claims 1 or 2, wherein the additional panels 49 to 53 fold over each other in the manner of a screen.  5. Boat, as defined in either of claims 1 or 2, characterized in that the additional panels 33, 34 slide one under the other by means of slides 0  6. Boat, as defined in either of Claims 1 or 2, characterized by the fact that the additional panels 45, 46 are articulated about vertical axes 47, 48 and can deviate laterally in the manner of aircraft wings with variable geometry.