FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
APPARATUS FOR WIND TURBINE BASED FOG HARVESTING;
SUZLON ENERGY LIMITED, A COMPANY INCORPORATED UNDER THE COMPANIES ACT, 1956, WHOSE ADDRESS IS ONE EARTH, OPPOSITE MAGARPATTA CITY, HADAPSAR, PUNE - 411 028, MAHARASHTRA, INDIA.
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE
PERFORMED.

Field of the invention; The present invention relates to harvesting water from fog or mist, and more particularly to apparatus for harvesting water from fog/mist in association with wind turbines.
Background of the invention:
In remote locations, the need of water is fulfilled by using alternate sources of water or by providing water through water tankers. Pipelines of water have proved very useful for supplying water to remote areas. Further, there are many locations where water reserves are very limited and because of the remoteness of such locations transporting water to such locations, by road, becomes very costly and time consuming. It is also not feasible to lay down pipelines due to various natural constraints.
Water table in the earth is decreasing. It has become extremely cost exhaustive to bore a hole in the earth in search of water. Further, due to decreasing water table reliability of finding water source under the ground is also very less. Alternate water sources are being explored for such remotely located areas. Atmospheric water can be seen as one of the alternatives of water sources.
The easiest way of having atmospheric water is by condensing the water using panels and collecting the water from the panels. Fog harvesting is one of the alternatives by which need of drinking water in remote areas can be fulfilled. Efforts have been made in the prior art to harvest water from atmospheric fog. Water harvesting system in the art generally employ pads or panels on which water is condensed that is further stored in a tank.
US 6828499 disclose an apparatus and method for harvesting atmospheric moisture that has a condensation panel to condense water when relative humidity is close to 100%. The

apparatus uses sunlight that is converted to electrical energy via photovoltaic system that is used to provide modest refrigeration on the face of panels. The apparatus doesn't use natural fog or mist to have water. There are chances of failure of the refrigeration system in the apparatus.
US 2002/0046569 to Faqih teaches an apparatus for the production of freshwater from extremely hot and humid air. The apparatus includes a modified commercial dehumidifier unit. Water vapour is condensed in the dehumidifier unit by conventional CFC refrigeration cycle. Ambient hot humid air in the surrounding is sucked and is forced out after removal of the humidity through the back duct. As the hot humid air enters the dehumidifier unit it passes by the cold surface of the coils of the refrigerant evaporator that cools the air as it condenses the water vapour in the form of droplets of fresh water that falls by gravity in container that collects condensate. The dry air flows over the balance of the refrigerant equipment to cool them before leaving refrigerant unit and exists as dry air at relatively high temperature.
US Pat No. 5846296 to Krumsvik discloses a method for recovering and/or purifying water which is absorbed from a humid atmosphere. The moisture from the air is adsorbed on a suitable medium such as a rack with trays in a defined space, whereupon by the application of heat the moisture is brought to a condenser where it passes into a liquid state and is collected in a suitable manner.
The aforementioned inventions do not relate to the present invention since they are generally based on the use of some refrigeration or cooling means.
There is a need of an apparatus that is mountable on a wind turbine nacelle that can generate water from the fog/mist in close proximity with the nacelle. An apparatus is further

needed that can deliver water from the wind turbine nacelle to a predefined location below the wind turbine.
Summary
An apparatus for wind turbine based fog harvesting includes a collector, a gutter assembly, a stand and a tank. The collector is supported by a pair of opposed poles that are coupled with the stand. The poles are approximately normal to the stand. The collector is preferably positioned behind a plane of the turbine rotors. The collector includes a mesh that receives a plurality of small water droplets because of pressure drop on the turbine blades. The collector is in close proximity with the turbine blades.
The gutter assembly includes a gutter having a plurality of vertical outlets, and a channel. One end of the channel is coupled with the outlets and other end is coupled with the storage tank. The gutter is positioned below and in close proximity with the collector. The gutter receives a plurality of big water droplets being formed from the small water droplets received on the collector. The stand is horizontally positioned on a nacelle of the wind turbine. The collector is movably positioned in close proximity with the nacelle with the pair of opposed poles.
In a preferred embodiment the collector is positioned above the nacelle. In another embodiment the collector is movably positioned below the nacelle. The apparatus of the present invention is useful for collection of water in remotely located areas in association with wind turbines.
Brief description of drawings

FIG. 1 is an apparatus for wind turbine based fog harvesting that is positioned on a nacelle of a wind turbine;
FIG. 2 is a perspective view of the apparatus for wind turbine based fog harvesting of FIG. 1;
FIG. 3 is a perspective view of the nacelle showing various positions of a collector in accordance with the present invention; and
FIG. 4 is a side view of another embodiment of the apparatus for wind turbine based fog harvesting of FIG. 1 that has the collector positioned below the nacelle of the wind turbine, and a toroidal tank around the base of a tower.
Detailed description of drawings
Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention. Referring to FIG.l, an apparatus for wind turbine based fog harvesting 100 is shown that is preferably positioned at a predefined location on a wind turbine 102. The wind turbine 102 includes a hub 104, rotor blades 106, a nacelle 108, and a tower 110. The fog harvesting apparatus 100 is preferably positioned on the nacelle 108 of the wind turbine 102. The fog harvesting apparatus 100 of the present invention is preferably positioned on the nacelle 108 of the wind turbine 102 with a horizontal stand 112.The stand 112 is horizontally securely coupled with the nacelle 108.
The fog harvesting apparatus 100 is positioned preferably behind the rotor blades 106 of the wind turbine 102.The apparatus 100 is flexibly positioned with the stand 112 on the nacelle 108 such that a plane of the apparatus 100 is normal to a plane of the stand 112. The

apparatus 100 is flexiblly positionable at any point on the stand relative to the rotor blades 106. The plane of the stand is preferably parallel to a central plane of the nacelle 108.
Now referring to FIG. 2, the fog harvesting apparatus includes a collector 202, a gutter assembly 204, a tank 208, and a pair of opposed poles 210. The opposed poles 210 are normally positioned on the stand 112 (FIG. 1). The poles 210 are coupled with the stand 112 (FIG. 1) preferably with brackets, screws, clamps, or the like. The collector 202 is positioned on the stand 112 (FIG. 1) that is further positioned on the nacelle 108 (FIG. 1) with the opposed poles 210. Thus the collector is supported by the pair of opposed poles 210 and positioned above the nacelle!08 (FIG. 1). The collector 202 includes a mesh or net made of, for example, polypropylene or nylon material. In the preferred embodiment, the mesh is 1.0 mm wide and 0.1 mm thick defining triangular weaves. The mesh may have any other weave forms, such as, for example, square, rectangular, rhombus, circular or the like. In this one embodiment, the shape of the collector 202 is preferably rectangular. Also the collector 202 is a planar construction.
The gutter assembly 204 is preferably positioned below the collector 202 in close proximity with a bottom end portion of the collector 202. The gutter assembly 204 includes a gutter 205, a channel 206, and a plurality of vertical outlets 207. The channel 206 is a tubular body that has two ends. One end of the channel 206 is coupled with the tank and other end of channel is coupled to gutter 205 through plurality of vertical outlets 207 of the gutter assembly 204.
In this preferred embodiment, the gutter assembly 204 has a plurality of outlets 207, however, the number of outlets is decided on the basis of the length of the gutter 205. The outlets 207 are coupled with the channel 206. The fog harvesting apparatus 100 is preferably positioned behind a plane of the rotor 106 of the wind turbine 102. The collector 202 is

positionable at various positions on the stand 112. In the preferred embodiment, the collector 202 is positioned above the nacelle 108.
Referring to FIG. 3, various positions of the collector 202 on the nacelle in association with the stand are shown. The collector 202 is positoinable at various location indicated by arrow Al, A2 and A3 above the nacelle 108. The collector 202 is positionable below the nacelle 108 as indicated by arrows Bl and B2. When the collector is positioned below the nacelle, the gutter assembly 204 is positioned below the collector 202 to collect the water droplets. The collector 202 can also be located behind the nacelle 108, as stand 112 can extend beyond the nacelle 108. It is understood, however, that the collector 202, in all positions, is located behind the rotor blades 106 (FIG. 1), in accordance with the present invention.
Referring to FIGS. 4, another embodiment the fog harvesting apparatus 100 of the present invention are shown. In this embodiment, the collector 300 is positioned below a central plane-C of the nacelle 302 in close proximity with the nacelle. Accordingly the gutter 304 assembly is securely positioned below the collector 300. Water collected in the gutter assembly 304 is supplied to a tank 308 through a pipe/channel 310 of gutter assembly 304. The collector 300 is positionable at any point on the nacelle 302 relative to rotor blades 312. The tank 308 is positioned on the ground, and around a tower 314 of the wind turbine. If the nacelle rotates about a central axis of the tower then the collector 300, gutter assembly 304 and pipe/channel 310 also rotate about the central axis.
As shown in FIGS. 2 and 4, the tank 308 is preferably positioned on the ground such that the tank is positioned around a tower 314 of the wind turbine, on the ground or the bottom plane on which the tower is mounted. In the preferred embodiment, the tank 308 has toroid shape or doughnut shape. The tank 308 preferably opens from the top. The tank

includes a passage inside for easy access to the tower and therefore to the wind turbine. In another embodiment, the tank 308 resides inside the nacelle 302 where water is used for cooling turbine components. Further, the water for drinking purpose flows through the inside of the tower from the tank 308 to a desired location. It is, however, understood that the tank 308 is not limited to the toroid shape, and that the tank 308 may have shapes like cylindrical, rectangular etc.
In operation, referring to FIGS. 1-3, the wind turbine rotates, and there is an air pressure drop across the blades width generally in a range of 5 to 10 KPa. A low pressure zone is formed in close proximity with the blade. The low pressure zone persists preferably in a range of 2-5 meters behind a plane of the blades. The pressure drop depends upon the height of the wind turbine. Greater the height, larger the low pressure zone. The pressure drop causes the wind to expand and that results into condensation. The fog is condensed on the collector where the water is initially accumulated over the net of the collector in the form of small vapour-water droplets. Hence the mesh receives a plurality of water droplets.
The small droplets of water unite to form big droplets of water that are further collected in the trough below the collector. The water accumulated in the trough follows the channel due to gravity. The water generated from the mesh passes through the gutter to the channel by gravity that is further collected in the central tank for further distribution. The wind turbines are mostly located in arid coastal areas and remote mountainous regions. Therefore, they are ideally situated to provide water at these remote locations. The efficiency of the collector depends upon the pressure drop that happens across a wind turbine that further depends upon the height of the wind turbine tower.
The present invention provides an alternative solution for having sustainable water for drinking purpose. It is to be noted that there is no release of gases such as CO2 during the

process of water generation in accordance with the present invention. The water table is not affected by the present invention. The invention doesn't employ any active components, such as an electric motor in the operation of the apparatus 100 of the present invention. The water generation at higher heights leads to development of high head of water that is delivered in the tank 208. The present invention advantageously provides a cheap and low maintenance apparatus 100 for drinking water harvesting in accordance with the present invention. The present invention advantageously provides alternate water source where no other conventional water supply is available.
The embodiments of the invention shown and discussed herein are merely illustrative of modes of application of the present invention. Reference to details in this discussion is not intended to limit the scope of the claims to these details, or to the figures used to illustrate the invention.

We Claim:
1. An apparatus for wind turbine based fog harvesting comprising:
a collector supported by a pair of opposed poles, the collector positioning behind a rotor, the collector including a mesh, the mesh receiving a plurality of small water droplets;
a gutter assembly having a gutter positioning below and in close proximity with the collector, the gutter receiving a plurality of big water droplets being formed from the small water droplets received on the collector,
a stand, the stand being horizontally positioned on a nacelle, the collector is movably positioned in close proximity with the nacelle with the pair of opposed poles; and
a tank, the tank positioning around a tower of the wind turbine on a bottom plane of the tower.
2. An apparatus for wind turbine based fog harvesting as claimed in claim 1, wherein the collector is movably positioned above the nacelle.
3. An apparatus for wind turbine based fog harvesting as claimed in claim 1, wherein the collector is movably positioned below the nacelle.
4. An apparatus for wind turbine based fog harvesting as claimed in claim 1, wherein a central plane of the nacelle is parallel to the plane of the stand.
5. An apparatus for wind turbine based fog harvesting as claimed in claim 1, wherein the gutter assembly includes at least one vertical outlet and at least one channel.
6. An apparatus for wind turbine based fog harvesting as claimed in claim 5, wherein the channel connects to the vertical outlet to receive water from the gutter.

7. An apparatus for wind turbine based fog harvesting as claimed in claim 1, wherein the channel connects to the tank to store received water therein.