System and method for harnessing wind energy

Abstract

The invention utilizes a ski lift for wind power generation outside of the ski season. The carriers on the ski lift are replaced by wind catching structures that pull the haul rope either uphill or downhill, depending on the prevailing wind. The haul rope rotates the electrical drive motor of the ski lift, causing it to generate electrical energy.

Claims

1. A system for harnessing wind power comprising, a ski lift having a haul rope and carriers, wherein the ski lift is arranged to be modified by replacing the carriers at least partly by wind-catching structures that are arranged to move the haul rope when wind affects at least some of the wind catching structures, wherein the haul rope is connected to a generator such that moving the haul rope is arranged to transfer mechanical energy to the generator which is arranged to produce electrical energy, and wherein the generator is an electric motor of the ski lift.

2. (canceled)

3. The system according to claim 1, wherein the wind-catching structures are arranged to be foldable or otherwise modifiable when the haul rope brings the wind-catching structures to a position where they are at least partly against the wind.

4. The system according to claim 3, wherein at both ends of the ski lift there is a bull wheel type structure and near the bull wheel type structures there are arrangements for closing the wind-catching structures before the haul rope brings the wind-catching structures around their turning points.

5. The system according to claim 1, wherein the haul rope is arranged to move in one direction regardless of the wind direction and wherein the wind-catching structures are arranged to catch wind in a part of the haul rope that moves the haul rope in said direction.

6. The system according to claim 1, wherein the haul rope is arranged to move in both directions and the direction of the haul rope is the direction where the wind catching structures are arranged to catch wind power.

7. The system according to claim 1, wherein the wind catching structures are parachutes, sails, rigid wing sail constructions or combinations thereof.

8. The system according to claim 7, wherein the wind catching structures are parachutes and are arranged to be open when in a tailwind and to be closed when facing a headwind.

9. The system according to claim 1, wherein the wind-catching structures are arranged to go up in a first position, to go down in a second position or vice versa and the selection of the position depends on the direction of the wind.

10. A method for harnessing wind power comprising: modifying a ski lift having a haul rope and carriers by replacing at least some of said carriers with wind-catching structures, allowing at least some of the wind-catching structures to be moved by wind and to in turn move the haul rope, and producing electricity through rotation of a generator by moving haul rope.

11. A system for harnessing wind power comprising, a ski lift having a haul rope and a plurality of wind-catching structures attached thereto, a bull wheel type structure at a top of the ski lift and another bull wheel type structure at the bottom of the ski lift, wherein the haul rope is configured to pass around both bull wheel type structures, and wherein movement of the haul rope is capable of turning both of the bull wheel type structures, a generator, which includes an electric motor component of the ski lift, connected to one of the bull wheel type structure, wherein the wind-catching structures are capable of moving the bull wheel type structures by moving the haul rope in response to a wind force, and wherein the generator is capable of producing electric power based on the movement of the bull wheel type structures moved by the haul rope in response to the wind force.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0020] In the following, the invention is described in detail. The description refers to the accompanying drawings, in which

[0021] FIG. 1 depicts a conventional ski lift, more specifically a surface lift of the platter type,

[0022] FIG. 2A shows a side view of the ski lift from FIG. 1, reconfigured for capturing wind energy,

[0023] FIG. 2B shows a top view of the ski lift from FIG. 1, reconfigured for capturing wind energy,

[0024] FIG. 3A illustrates the ski lift from FIG. 2B in its entirety, while capturing wind energy when the wind is blowing uphill, and

[0025] FIG. 3B illustrates the ski lift from FIG. 2B in its entirety, while capturing wind energy when the wind is blowing downhill,

DETAILED DESCRIPTIONS

[0026] The embodiments in the following description are given as examples only and someone skilled in the art can carry out the basic idea of the invention also in some other way than what is described in the description. Though the description may refer to a certain embodiment or embodiments in several places, this does not mean that the reference would be directed towards only one described embodiment or that the described characteristic would be usable only in one described embodiment. The individual characteristics of two or more embodiments may be combined and new embodiments of the invention may thus be provided.

[0027] The purpose of a conventional surface ski lift, as shown in FIG. 1, is to tow skiers up a slope (1). To this end, carriers (2)in this picture, by way of an example, of the platter typeare clamped to a haul rope (3) and move uphill on one side of the ski lift and return down on the other side. The haul rope loops around two bullwheels (4), one at the top and the other at the bottom. An electrical motor (5) drives the top bullwheel, providing motion for the haul rope. In-line towers (6) support and hold down the haul rope.

[0028] The embodiment, depicted in FIG. 2A, from the side and in FIG. 2B from the top, is based on the conventional ski lift pictured in FIG. 1. A drogue parachute (10) is connected at its apex with a spring coil (11) to a vertical bar (12) that swivels from a fixed grip (13). The grip is clamped to the haul rope (3). A weight (14) located at the bottom of the bar keeps the bar upright at all times. The shroud lines (15) of the parachute are connected to a recoiling rope mechanism (16) that winds and unwinds a rope (17) under spring action, similar to when the said mechanism is connected to a carrier in normal ski lift operation. The recoiling rope mechanism is fixed to the haul rope with a fixed grip (18).

[0029] When the wind blows uphill (19), the left drogue parachute (10) deploys under the influence of the wind, pulling out the rope (17) from inside the recoiling rope mechanism (16). The force exerted by the parachute is transferred through the haul rope (3) to the electric generator (20), causing it to rotate and produce electrical energy.

[0030] The right parachute (10), which travels against the wind and downward is held in a collapsed, low-drag state by its spring-loaded recoiling rope mechanism (16).

[0031] At both ends of the lift, curved blade assemblies (21) collapse the open parachutes before they round their turning points. The bullwheels (4) are fitted with rotating guide rods (22), which ensure that the collapsed parachutes won't get entangled. The distance between the ski slope (1) and the haul rope (3) determines the maximum diameter of the parachute (10). The vertical bars (12) and the recoiling rope mechanisms (16 and 16) with their respective grips (13 and 18) can traverse the shears (23) on the in-line towers (6) in a similar fashion to the carrier assemblies on a normally-configured ski lift.

[0032] To reduce cost, it is advisable to reuse the structures and the electric motor that drives the ski lift in normal operation for power generation, with the electric motor functioning as an electrical generator when the ski lift is configured for wind energy production. For example, the spring-loaded recoiling rope mechanism as found on surface lifts, can be utilized in opening and closing the parachutes.

[0033] When the carriersthe tow bars (T, J and platter type), chairs or gondolasare replaced by the parachute assemblies on a one-to-one basis, in dimensioning the latter, the energy consumption of a single carrier can serve as a yardstick for the amount of energy a single parachute should produce. In the following calculation, it is assumed that the number of drogue parachutes equals the number of carriers that they replace. If the motor of the ski lift draws 27 kW moving 18 carriers, the energy consumption of a single carrier is 27 kW divided by 18, equals 1.5 kW. When the ski lift is reconfigured to produce the same amount of energy from the wind, the same number of parachutes, 18, is used. Since the power generated by a parachute can be calculated from the accepted rule of thumb 3.1 m.sup.2/kW at a wind speed of 8 m/s [1], the surface area of a parachute needs to be 4.7 m.sup.2. It follows that its diameter is 3 m.

[0034] Since the parachute assemblies move up and down the ski slope, fixed to the haul rope on opposite sides of the ski lift, their added weight poses no problems. The extra weight is eliminated with the same counterweight principle as employed in a traditional elevator, leading only to friction losses. Since the parachute assemblies weigh as much going upward as downward, better balancing is achieved than when the ski lift operates in its traditional role, in which the bars, chairs or gondolas always descend empty, without skiers.

[0035] On a ski slope the wind is blowing from the foot upwards for most of the time, but under certain climatic conditions or at certain times during the day the wind will blow down the slope instead. The invention autonomously adapts to either condition, as shown in FIG. 3A and FIG. 3B. In both figures, reference numbers 30 mark deploying parachutes. Similarly, numbers 31 point to fully deployed parachutes. Collapsing parachutes are marked with numbers 32. Fully collapsed parachutes are referenced by number 33. Arrow 34 indicates an uphill wind, while arrow 35 represents a downhill wind. It should be noted that the haul rope always turns in the same direction clockwise in FIG. 3A and FIG. 3Bregardless of the prevailing wind.

[0036] As many drogue parachutes can be anchored to the haul rope of a ski lift as space and strength of the construction permit. Their number can be equal or higher than that of carriers on a conventional ski lift.

[0037] In another embodiment of the invention, wind energy is harnessed using a sail structure similar to that on a sailboat. Also, rigid wingsail constructions that swivel or change shape can be used instead of a more conventional sail. A sail or wingsail has the advantage of better versatility in a wider variety of wind conditions. However, a drogue parachute solution appears to be the most economical and least complicated in use.

[0038] Some advantageous embodiments of the method and device according to the invention have been described above. The invention is however not limited to the embodiments described above, but the inventive idea can be applied in numerous ways within the scope of the claims.

REFERENCES

[0039] [1] The Nature of Boats: Insights and Esoterica for the Nautically Obsessed, Dave Gerr, McGraw Hill Professional, 1995, ISBN 007024233X, 9780070242333