GB1605037A

GB1605037A - Recovery of energy from wind

Info

Publication number: GB1605037A
Application number: GB33127/77A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1981-12-16

Description

(54) RECOVERY OF ENERGY FROM WIND (71) I IVOR GRAY NIXON, a British subject of ler Stock Ost "Matterhorngruss", Zermatt 3920, Valais, Switzerland, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to the recovery of energy from wind, in an economic manner, by providing means for the concentration and recovery of the relatively low levels of wind energy available at the Earth's surface, optionally together with solar energy from solar radiation.

In view of the limited amount of fuels available as energy sources, whether carbonaceous or fissionable fuel, and their increasing cost, improved methods of utilising wind and solar energy are needed. Present methods are relatively uneconomic except under favourable circumstances. For example, solar radiation has been utilised by means of solar plate collectors, which absorb heat to provide hot water for domestic and industrial use and for the heating of residences. The solar collectors used are, for example, flat plate collectors usually equipped with a flat glass cover plate parallel to it. The collector plate is preferably blackened and has fluid conduits bonded to it, the fluid being heated by the absorbed heat and removed for use.Alternatively, air is blown through the space between the cover and absorption plates, taking up heat from the absorption plate, and is then circulated through the residence. Attempts have also been made to convert solar radiation directly into electrical energy, by assembling a large number of solar cells or thermocouple junctions on the heat absorption plate which produce an electric current from part of the solar energy.

However, the results from these methods are inadequate to give an economic solution to the problem, except under favourable circumstances, because of the low energy level of the impinging solar radiation. The intensity of solar energy falling on the earth's surface is relatively low per unit or surface area, and due to the angle of impingement of the solar rays is appreciably less in temperate regions were domestic heating is most needed. Moreover, the intensity of this radiation is normally only adequate for heat recovery during full daylight hours, and in fine weather when the sun is shining, so that the derived heat supply is not continuously available as required. This problem has to be met by providing large and expensive heat storage capacity, as the major domestic heating load occurs during the colder night hours.Wind power is an alternative to solar energy, and windmills have long been used to recover energy from wind. However, they are relatively large machines for their power output, utilising rotary sails of large dimensions, which are costly and inefficient.

The present invention provides means for recovering energy from wind comprising a wind flume and dam (as herein defined) and a means for converting concentrated (higher velocity) wind into usable energy located approximately at the apex of the wind flume.

The wind flume is used to concentrate the wind energy and the wind dam is provided to contain and lead the concentrated wind energy through the means for converting wind into usable energy. The means for converting wind into usable energy generally converts the wind into mechanical or electrical power and is for example a wind turbine or fan. This may have the usual gearing to couple it to an electric generator for the conversion of the mechanical energy to electric power.

The side walls, floors and roofs of the wind flume and the wind dam may be formed at least partly by the walls of buildings which may be partly those of existing buildings which are incorported into the wind flume and wind dam. Alternatively walls, floors and roof of the wind flume and the wind dam may be formed at least partly by natural geographical features. For example, the floor of a converging valley can comprise the floor of a wind flume, and the converging walls of the valley its side walls, while if the floor of the valley rises as it approaches the apex then only a small dam will need to be built across the apex with a roof to contain the wind so that it passes through the wind turbine.

The invention also provides an integrated system for utilising solar energy and energy from wind comprising a combination of a means for recovering energy from wind as defined above with a means or apparatus for utilising solar energy derived from solar radiation.

Such a combination permits for example the recovery of sufficient solar energy to meet normal domestic requirements both for heating and electrical energy.

Preferably the means for utilising solar energy from solar radiation comprises a plurality of parallel strip lenses to concentrate solar radiation into a series of parallel bands and means for converting the radiation into usable form located approximately at the focal length of the strip lenses where the radiation is concentrated.

The means for converting the radiation into usable form may comprise one or more conduits through which a fluid is flowing, the solar energy radiation being absorbed by the fluid which is heated thereby. The heated fluid can be used for space heating or for the generation of electrical energy. The fluid may contain in solution a dye suitable for absorbing radiation, preferably a black dye or may contain a black powder such as graphite in suspension for the purpose of improving the absorption of the radiation. The fluid may be water, antifreeze solution or a heat transfer fluid. Alternatively the fluid may be a gas such as air.

The means for converting the radiation into usable form may also comprise one or more rows of solar cells for converting the radiation into electrical energy. The solar cells may be cooled to permit use of a higher concentration of energy without damage to the cells. For example the solar cells may be cooled by a stream of cooling air conducted over them through a conduit transparent to solar rays. The air heated thereby can then be utilised as a low level heat source for the space heating of buildings. Alternatively or additionally the solar cells may be cooled by a liquid refrigerant from a heat pump circuit as it evaporates before being compressed and recycled.

Two or more strip lenses may be inclined relative to one another at an angle such that the bands of concentrated solar radiation from these strip lenses are superimposed on one another and are focussed on the same means for converting the radiation into usable form.

In this manner a concentrated strip of solar radiation from a number of lenses is focussed onto one conduit or one row of solar cells so that the intensity of the solar energy is increased and the number of conduits or rows of solar cells required is reduced accordingly.

The means for converting the radiation into usable form may be provided with at least one heat or light sensing device and means may also be provided for moving either the means for converting the radiation into usable form or the strip lens assembly so that the bands of concentrated solar radiation remain in register with the means for converting the radiation into usable form despite the motion of the sun. The means for moving either the means for converting the radiation into usable form or the strip lens assembly may comprise a servo-motor and mechanical linkages or a mechanical device and linkages actuated by differential metal expansion on heating.

The present invention thus provides means for recovering energy from wind, optionally in combination with a means for concentrating solar energy directly from solar radiation, so as to recover more energy at a more continuous rate than is possible from either source alone.

According to the present invention, means are provided for concentrating the force of the wind and using it to drive a much smaller machine for harnessing wind power more cheaply than the windmills which are currently used. The said means for concentrating the wind power consist of a wind flume and dam. A wind flume can be defined as a structure having a decreasing area of cross section such that it tapers towards an apex, and is thus capable of concentrating, i.e. increasing the velocity of, wind. The wind flume is provided with a wind dam in the form of a roof.

The wind flume will usually allow the wind to escape into open air after it has passed the apex of the flume, however in some cases buildings or geographical features may provide a diverging structure following the apex of the wind flume. Such a diverging structure, if present, should not be roofed in any way, either with a wind dam or otherwise, so that the wind can escape upwardly without obstruction into the open air and the term "wind flume and dam" is to be construed accordingly.

The wind flume can be specially constructed for the purpose, but is preferably realised by adapting or utilising existing features. For example, the said wind flume can be achieved by adapting architectural or geographical features for the purpose. It is possible to provide the wind flume with means for rotating it to face the wind direction, but in general it is more economic to locate one or more of the said wind flumes facing the prevailing directions of the winds.

In the case of a single wind flume this will normally face the direction of the prevailing wind. In order to concentrate the wind at the apex, and ensure that the bulk is directed into the machine, the flume is provided with a wind dam comprising a preferably sloping roof which closes in completely the upper part of the wind flume as it approaches the apex, so as to dam up the wind and force it to pass through the said machine. The shape of the walls of the wind flume, and the roof acting as a dam, are preferably determined by wind tunnel tests for each type of installation. The said machine can be a wind turbine or windmill of any known type, and the wind outlet from it can be exhausted to the open air.The said wind flumes can be a domestic utility, such as a car port or sun-verandah, with the roof of it forming the wind dam, or a bar or similar utility accommodation adapted for the purpose.

The said machine can be used to generate mechanical power, but is more conveniently coupled directly to an electric dynamo to generate electricity for use or storage. The said electrical energy can then be converted to heat, as and when convenient, at a high heat level. For example, it can be used in the first place to meet the immediate electric power requirements of the dwelling, and any surplus stored in electric batteries for later use as current or alternatively fed to an immersion heater in the hot water storage tank in which heat recovered from a solar plate collector is topped up to a higher heat level. A further alternative for storing the surplus electric energy can comprise an electrically heated resistance coil or immersion heater located centrally in an heat storage reservoir, such as gravel or rock, in which it can be stored at a high temperature level.

Existing geographical features can also be utilised or adapted to harness the wind's energy, by providing existing wind flumes with a wind dam and a wind turbine or windmill located at its apex. Such means for concentrating the wind's energy and converting it into power, either mechanical or electric, and preferably located in areas where high velocity winds are common and blow generally in the direction of the said wind flume for a substantial period of time. For example, a valley or tapering ravine trending upwards, located in a hill or mounting range or a seaside cliff, can be provided with a wind dam at its upper end to trap the wind blowing up the wind flume.The said wind dams can be constructed from relatively light weight material, such as reinforced or prestressed concrete, adequate to resist the highest wind velocity which would be encountered, and landscaped to fit into the surroundings. An added advantage of the said wind dams would be that the expansion of the concentrated wind, through the said machine converting it into useful energy, causes a drop in its temperature as the wind expands freely into the open atmosphere, preferably at the head of the said valley or ravine. Such expansion of the air exhaust from the wind machine will result in the condensation of moisture from the air, providing nuclei for the formation of rain or snow when the humidity of the wind is sufficiently high.By installing said wind dams and wind machine installations in suitable locations moist air will thus provide rain or snow on the downwind side of a mountain range, under favourable conditions, where the water catchment area is not otherwise adequately provided with water.

It is advantageous to install a wind energy concentration and recovery system together with means for utilising solar energy from solar radiation, as they are complementary particularly in the case of domestic installations. The solar energy is available at higher levels during full daylight hours in fine weather, while the potential of wind energy tends to be greatest during stormy weather when the sky is overcast and solar radiant energy is at a low level. Moreover, wind energy is also available at night-time. Thus, the simultaneous recovery of both forms of energy gives a greater and more uniform supply of utilisable energy. Moreover, wind energy can be directly utilised for the generation of electrical power by coupling the wind turbine, fan or windmill to an electric motor.This is of great advantage, for example, for supplying all requirements for domestic purposes, electrical as well as heat, particularly in remote and isolated places. By providing adequate energy storage capacity the complete energy requirements for domestic purposes can normally be met for the full twenty-four hours of the day, but a standby energy machine powered by, say, diesel oil or mains electricity can also be provided to meet requirements under abnormal conditions. Normally, the electricity needed for electric lighting and for driving appliances is provided by windpower, and from storage batteries; while surplus to requirements at any time is stored in electric storage batteries in the first place, and then any remaining surplus converted into heat, for example by an immersion heater, and stored in the heat storage bank.The domestic heat needs are normally met from the heat recovered from solar radiation by the solar heat collector assembly, supplemented by heat derived from the heat storage facilities or banks. The said heat banks can comprise hot water storage tanks, beds of gravel or rocks suitably insulated, or vessels containing low melting point hydrates of salts in which the heat is stored in the form of latent heat of fusion. All these forms of heat storage banks are well known and need no further description.

When electrical or mechanical energy, either derived from wind power, or from a standby machine, say, a diesel engine or motor powered from the electric mains supply, is being used to meet heat requirements the use of an heat um is advantageous. In the said heat pump a suitable refrigerant, such as Freon, is circulated in a closed circuit through a heat pump compressor and the compressed and heated gas is cooled in a heat exchanger counter-current to water as the cooling fluid which is thereby heated for domestic purposes (Freon is a Trade Mark). The cooled gas is then heated and evaporation completed by means of solar energy and recirculated to the said heat pump, the cycle being continued indefinitely. The said heat pump cycle is well known and requires no further description.In said cycle it is also preferable to include domestic refrigeration in it, the refrigerator, deep freezer or cold room involved being inserted in the refrigerant cycle after the compressed refrigerant has been cooled in the said heat exchanger. The capital cost saving for the domestic refrigeration equipment can be credited against the cost of the solar recovery complex.

The novel principles incorporated in this invention increase the amount of energy which can be recovered. Thus the concentration of solar radiant energy and wind energy make it viable to recover said energy sources at levels which would otherwise not be utilisable. For example, windmills are not currently viable for wind velocities below about 10 kilometres per hour, so that the recoverable wind power is reduced accordingly. However, in the said wind flume and dam, with decreasing cross section, it is possible to increase the wind velocity at the apex in the said flume to, say five times the initial velocity.As the wind power generated by, for example, a windmill Is theoretically proportional to the cube of the wind velocity the use of the said wind flume and wind dam results in a considerable increase in the period during which it is viable to recover wind power, and in the amount which can be recovered because the area over which the kinetic energy of the wind is harnessed is considerably increased. Similarly, the radiant energy from the sun reaching an heat collector plate assembly during early morning, late afternoon or in cloudy weather, particularly in the temperate zones is inadequate for viable heat recovery because the energy level is too low. Concentration of radiant energy on the heat collector conduits raises the energy level sufficiently to warrant recovery.Provision for the recovery of the heat at two different energy levels, in line with domestic requirements, is a further advantage as it is pointless to mstal expensive equipment to recover the radiant energy at an higher heat level than is necessary. The simultaneous recovery of energy from radiant solar energy and from wind power increases the amount of recoverable energy to a point that all normal domestic requirements can be met under favourable conditions, and is particularly valuable for remote and isolated locations. The high costs of linking up the residence to mains supply of electricity, and of bringing energy in the form of fuel, is saved and can be credited towards the cost of the solar energy recovery.

The means for concentrating energy from solar radiation preferably comprises the use of multi-strip lenses in parallel as the cover plate for the heat collector plate, replacing the flat plate conventionally used. In this manner the solar radiation is concentrated to give a series of narrow bands, parallel to one another, of concentrated radiation at a higher heat level, at the focal length of the strip lenses. The said bands impinge on the metal pipes or conduits incorporated in the collector plate, heating a fluid flowing through them, the heated fluid then providing heat for domestic and other uses. A normal lens concentrates rays falling on it at its focal point, but in contrast a strip lens focuses the radiation into a narrow band instead of to a point.A strip lens can be defined as a lens with the normal axial section of a conventional lens at right angles to its long axis, and with a rectangular section in any plane parallel to its ong axis, as shown in Figure 1. When solar radiation falls on the said strip lends, with the long axis of the lens located for example at right angles to the direction of the impinging rays, the said rays are focused by the strip lens into a narrow band at the distance of the focal length of the lens from it, the said band being parallel to the long axis of the lens. The said focal length is defined by the customary lens formula: Equation 1: I/f = (n-1) (lIr1 - 'Jr2), where, n is the refractive index of the material of the lens, f is the focal length, and rl and r2 are the radii of curvature of the two surfaces of the lens for a section at right angles to the long axis of the strip lens. Any suitable known type of configuration for the said surfaces can be used, for instance a plano- concave or double concave lens section, the type, properties and curvature of the lens surfaces being chosen to give the optimum focal length for the selected distance between the multi-strip lens cover plate and the heat collector plate.The said strip lens cover plate can be easily and cheaply moulded from glass or transparent plastic, and can be composed of one or more materials, having different refractive indices, which can be liquid or solid. For example the said moulded cover plate can comprise two solid envelopes sealing in a liquid of suitable refractive index, the said envelopes being moulded to give the desired strip lens configuration. The said cover plate does not need to be moulded with a high degree of optical accuracy, as some degree of scatter can be accepted for the narrow band of concentrated energy for each strip lens incorporated into the cover plate. The said heat collector plate is furnished with conduits for the heating of the fluid flowing through them.The said conduits can comprise, for example, metal pipes bonded to the heat collector base plate, both pipes and collector plate being blackened to assist radiation absorption. The said conduits are located parallel to one another and equidistant, in a similar manner to the strip lens located in the cover plate.

Normally the highest efficiency and best overall heat recovery over the year is achieved by tilting the cover plate assembly at an angle towards the Equator. For example, in the Northern hemisphere the angle can be equal to the latitude or slightly greater, say 15 degrees more. Said angle could thus be between 40-55" for a location at 400 North latitude.

The problem of concentrating the solar radiation by parallel multi-strip lenses is complicated by the motion of the sun through the sky. As the sun rises the strip images at the focal point of the lenses can for example be displaced downwards, and this movement can be compensated for by providing means for moving the collector plate assembly in a direction parallel to the cover plate by an amount equal to said displacement. The said means may comprise a heat or light sensor device, located on the collector plate, which actuates a servo-motor and mechanical linkages to give the desired movement. Alternatively, a purely mechanical device can replace the servo-motor using the principle of of differential metallic expansion, when heated by the solar radiation, to provide both the sensor and mechanical leverage needed to move the said collector plate.These sensor devices move the collector plate the necessary amount, and in the necessary direction, so that the images of the parallel strips of concentrated energy impinge upon the conduits at all times in accordance with well known and estabLished principles for such sensor controls.

Alternatively, the width of the heat collecting conduits, for example a flattened metallic tube, can be increased so that the strip image of concentrated solar energy can remain impinging on the conduit during the peak period of the day so that sufficient heat can be collected by said conduit to meet the higher level domestic heat requirements. The lateral movement of the sun across the sky is a further complication. If, as a consequence, the solar rays fall on the strip lenses at an oblique angle to a plane at right angles to their long axes, some diffusion of the strip image will result, for instance, in the early and late daylight hours. This diffusion can be partly compensated for by increasing the width of the heat collecting conduits, and/or by providing means for the recovery of the said diffused solar energy as a lower level heat supply.

For domestic purposes the heat requirements can be divided into two categories: low grade heat at, say, 40"C for the heating of living space normally up to about 20-25"C, and higher level heat for hot water up to about 60or. These requirements can be met in an economic way by providing the heat collector plate with means for recovering the solar energy at two different heat levels to meet these requirements. For example, the strip lens cover plate can concentrate said energy on the conduits on the heat collector plate during the most favourable period of daylight hours, and the diffused energy, particularly that arising from the effect of the sun's motion through the sky, can be also harnessed by providing additional means for recovering this energy at a lower heat level.The said additional means can comprise the circulation of a small amount of air over the collector plate and means for delivering it, warmed to, say, 15-25"C to the main living space of the dwelling to provide base warming for it. To obtain improved heat absorption the heat collector plate is preferably blackened, and the base of the said plate is insulated to prevent loss of heat. In this manner domestic heat requirements can be met economically at both the desired levels of, say, 20"C in the living space and 60"C for hot water. In order to reduce the investment cost for solar heat collector assemblies, it is desirable to design them to meet a dual role.Thus the said assemblies can be made weather proof so that they act as a roof, while the insulation on the base of the collector plate acts as roof insulation which is now normally installed in well constructed buildings.

Solar cells, such as the silicon cell, can be substituted for the heat collecting conduits in the solar collector assembly, so that the concentrated energy obtained by using the multi-strip lens cover plate falls on a row of said solar cells. Unfortunately the high cost of present solar cells makes them relatively uneconomic, except under special circumstances, and the amount of said solar energy concentration they can at present handle is limited as they cannot stand the higher temperatures simultaneously involved. By using the method of collecting the solar energy at two different heat levels described above, the use of improved solar cells being developed should become possible.By passing the small stream of air, used to provide warmed air at the said lower heat level, as a cooling stream directed on the row of solar cells, it becomes possible to increase the amount of solar energy concentration which can be tolerated by the solar cells. Alternatively or additionally the solar cells can be cooled by means of the liquid refrigerant used in a heat pump circuit (before it is heated) when evaporated as described below. The solar cells convert the solar energy which impinges on them partly into electric current which can be utilised as such. It is also possible to substitute rows of multiple thermocouple junctions for the silicon solar cells, but the efficiency is low.

It will be appreciated that the present invention, utilising a wind flume and dam for recovering wind energy, optionally in combination with means for utilising solar energy from solar radiation, can be applied in many different variations and combinations, to meet the exigencies of the location and its requirements.Some examples are described below with reference to Figures 1 to 5 of the accompanying drawings, which are schematic sections or flow diagrams, and are not drawn to scale, and in which: Figure I shows an assembly for the recovery of solar radiant energy for use in an integrated system with wind flumes; Figures 2 and 3 show simplified schematic flow diagrams and layouts for integrated systems; Figure 4 shows a modification of an assembly for the recovery of solar radiant energy for use in an integrated system with a wind flume; and Figure 5 shows a system for the use of existing geographical features for the generation of wind power.

Figure 1 shows a heat collector plate assembly 1 for the recovery of solar radiant energy, using parallel multi-strip lenses 2 moulded into a glass cover plate 3 of the said collector plate assembly. These lenses concentrate the solar energy into parallel narrow bands of energy, the rays being focussed at the focal length 4 of the lenses so that they impinge on blackened metal tubes 5 through which circulates a fluid, say, water to be heated by the absorbed radiant energy. The said fluid is circulated through a hot water tank by piping 6, and the hot water utilised for domestic purposes in the customary manner. The said metal tubes are parallel to one another at a distance apart commensurate with that of the multi-strip lenses, and are bonded to a blackened base plate 7 which is provided with an heat insulating layer 8 on its back.One or more of an adjacent group of parallel strip lenses can be tilted at an angle so that a plane at right angles to the curved section of the lens is tilted relatively to the adjoining strip lens or lenses, the said angle being such that the concentrated band of energy from each strip lens in the said group is focussed on one heat collecting tube 5. For example, groups of three adjoining strip lenses can be moulded into the cover plate 3, with each outer member of the said group being tilted at that angle, determined by the focal length of the lenses, which will focus the bands of concentrated energy on a single heat collecting tube 5, or conduit. In this manner the number of said tubes required is reduced to one third.The strip lenses and parallel tubes 5 can be installed either horizontally or vertically, and the heat collector plate assembly 1 preferably is located facing the midday sun and at an angle determined by the latitude of the location of the installation. Two heat sensors, for example in an installation in which the parallel strip lenses and the said tubes 5 are horizontal, are mounted (respectively 9 and 10) on the lower and upper sides of one of the said tubes 5 and actuate means for moving the whole base plate 7 respectively downwards and upwards when the said band impinges on the said sensors. The said means comprises a servo-motor and mechanical linkage for moving the late 7 in the customary manner (not shown in the Figure 1).In this manner all the parallel bands of solar energy focussed on the tubes 5, which are also parallel, are kept in register with them as the sun rises and declines in the sky. One alternative is to replace the blackened metal tubes 5 by plastics tubes transparent to the rays falling on them, and bonded to the base plate 7. Preferably the said plastics tubes can be blackened on their lower hemispherical surface internally and have an oval cross section so that if the fluid being heated should freeze the tube will not be ruptured by the resulting expansion. To improve heat absorption by the fluid it can incorporate a black powder such as graphite, which is finely divided and held in suspension by an emulsifier. Alternatively, the fluid can contain a dye, for example a black dye, which will increase heat absorption by the fluid. A further alternative is to furnish the base plate 7 with a plastics cover plate, transparent to the solar radiation, with the cover late, and/or the base plate being moulded so that conduits for the flow of the said fluid are formed between the two halves of the sandwich which are sealed together forming a base plate with integral conduits within it.

The invention is further illustrated with reference to the following Examples and Figures 2 to 5 of the accompanying drawings.

Example 1 This Example describes one possible combination in the form of a joint installation, for the recovery of solar radiant energy together with wind energy, suitable for utilisation in a remote area, for example a remote farm complex. The installation would provide a full range of facilities to meet requirements: residential space heating, hot water, electric power for lighting and domestic appliances, and refrigerated storage for part of the farm produce.

A simplified schematic flow diagram and layout is shown in Figure 2 for the installation comprising solar energy collection plates 1 (for example, as shown in Figure 1) used as roofs for the farmhouse building and auxiliary buildings, a wind flume 4 formed by utilising the walls 5 of suitably located buildings to enclose spaces for utility usage such as a storage place 3 which is covered by a roof acting as a wind dam 6. The said wind flume and dam is oriented in the direction of the prevailing winds, and is furnished with a wind machine, for example a windmill or wind turbine, at the apex of the converging wind flume to convert the energy of the entrapped wind into mechanical energy, the said machine 7 being used to drive an electrical generator 11 which furnishes electric current to meet requirements.Any surplus to the said requirements is used to charge electric storage batteries 12 and to convert the remaining surplus into heat by feeding it to an immersion heater 21 located in the hot water storage tank 13 or other heat storage bank. A 'heat pump', comprising a compressor 8 driven by an electric motor 25, circulates a refrigerant (for example, Freon) through a refrigeration cycle comprising condenser 19, piping 27 domestic appliances 9 (for example refrigerators including deep-freeze facilities and equipment for air conditioning and solar evaporation plates (on a roof with a southern aspect) 22. A standby machine can be provided to furnish energy when electric power is not available from wind power or the storage batteries 12, for example a diesel engine 10 or alternatively an electric cable 26 can link the electrical circuit 24 to a mains supply from outside.The water circulating system comprises piping 17 circulating cool water from the bottom of water storage tank 13 through successively heat pump condenser 19 and solar heating conduits 16 back to the top of the hot water storage tank 13 by means of circulating pump 15. Hot domestic water is drawn from an upper level of said tank through line 18, and also circulated by thermosyphon through hot water radiators 27 back to the bottom of tank 13. Cold make up mains water is fed by line 20 through condenser 19, which has parallel cooling water flow comprising this cold water stream in parallel with the water drawn from the bottom of tank 13.Electric cable circuitry 24 links the electric power generated by dynamo 11, which is driven by wind machine 7 or diesel engine 10, to the electric motors 23 and 25, immersion heater 21 and storage batteries 12, as well as the wiring system for the domestic lighting and electrical appliances 28.

The usual bypass facilities for fluid flow, control means and instruments, for example those needed to swivel the wind machine to best meet the wind direction and to control its maximum speed, and to switch any electric surplus generated successively to the storage batteries 12 and immersion heater 21, are provided but are well known and are not shown in the condensed flow scheme in Figure 2.

Example 2 This Example describes one possible combination designed to meet the requirements of a domestic residence utilising a joint installation for the recovery of solar radiant energy and wind power. The flow diagram is similar to that given for Example 1 in Figure 2, but the layout plan is modified to meet domestic requirements, as shown in the ground plan given in Figure 3 in simplified form. The said layout plan is for a residence facing south in the northern hemisphere, in a location where the prevailing winds are from the southwest. The heat collector plates are placed on the southern slope of the roof, and/or the south wall of the house, and a wind flume 4 is provided by building a wall 29 at right angles, or approximately so, to the north wall of the house 34, so that the said flume faces approximately into the directions of the prevailing wind.The wind flume is roofed to form a wind dam 6, and a wind machine 7 is placed at the apex of the wind flume 4 and connected to drive an electric dyamo 11 to generate electricity which is delivered to the electric cable circuitry 24 for distribution to domestic consumption and storage of any surplus. The roofed wind flume 4 can be utilised as a sun porch 2. The upper surface of the wind dams 6 can be used as a verandah, or as an alternative the wall 29 can be extended upwards, and a further wind dam built to roof the enclosed space, forming a further wind flume, while if desired the ground floor space 2 can be enclosed and used as rooms, as wind recovery is more efficient above ground level.It can also be advantageous tb extend the roof to form projecting eaves above the southern wall 32, and add small wing walls 31 to make the space 30 bounded by them and the said eaves under a further wind flume and dam, in this case acting as a feeder flume to the main wind flume or flumes 4.

For installations described in both this example and in Example 1 it is, of course, possible to leave out one or more of the features described, as dictated by the requirements and investment capital available. For example, the heat pump assembly, and the refrigeration facilities could be omitted.

Example 3 This Example describes one possible modification of the heat collector plate assembly 1, described and shown in Figure 1, and utilised for instance in Examples 1 and 2, which permits the use of the solar radiant energy for the production of electric energy as well as the production of hot water at a higher temperature. This modification is illustrated in Figure 4. Groups of three parallel strip lenses are moulded into the plastics cover plate, with each outer lens in the group being set at such an angle to the central lens that the concentrated bands of solar radiant energy from each group are concentrated on a single conduit 5. The said angle is determined by the focal length of the lenses. The pattern of said groups of three lenses so inclined to one another is repeated across the whole cover plate.

The said conduits are manifolded together by piping system 12, the inlet being fed by pump 8 with a suitable low boiling point fluid, which is vapourized in said heated conduits 5, the vapours from the outlet manifold driving a turbine 29 which is coupled to an electric generator 11. The exhaust of said vapours from the turbine 29 are condensed in heat exchanger 19, cooled by water fed in parallel with cold make-up water fed through line 20 and cool water from the bottom of hot water tank 13, the warm exit water being circulated by lines 17 back to the said water tank (Figure 4A). The conduits 5 can be substituted by rows of photovoltaic cells 35, for example silicon solar cells.As the solar energy concentrated by the triple combination of the strip lenses 2 can overheat and damage the said cells they are covered over by an hemispherical plastic dome, and cooled by blowing air through it by means of a blower and air piping (not shown). The heated air leaving the said domes 39, which are bonded to the collector plate base 7, is then used as a source of domestic heat. The heat collector assembly 1 (Figure 4) shows a module, forming part of the whole assembly, comprising only two conduits 5 and two rows of solar cells 35, but the whole assembly can contain as many of each as desired or alternatively comprise only conduits 5 or silicon cells 35 as desired.

Example 4 This Examples describes one possible form for the utilisation of existing geographical features for the generation of wind power. The valley walls 4 and the rising floor of the valley 6, leading up to the pass 5, form a wind flume 1 which traps the wind force by means of a wind dam 2 built as a roof over the upper end of the valley. Windmills or wind turbines are installed at the apex of the valley 5, and utilise the wind force trapped to drive electric generators (not shown). The said windmills or turbines 3 exhaust the wind driving them into the open air 7 on the other side of the pass 5. The layout is shown, in simple schematic form, as a projection in Figure 5, with vertical sections shown in Figure SA at the entrance of the valley, and as Figure SB at the pass.Details will depend on the actual geographical features available, but the aim is that the area of cross section of the valley at the edge of the wind dam 2 should be as great as possible compared with that at the machines 3 at the apex.

WHAT I CLAIM IS: 1. Means for recovering energy from wind comprising a wind flume and dam (as herein defined), and a means for converting concentrated (high velocity) wind into usable energy located approximately at the apex of the wind flume.

2. Means as claimed in Claim 1, wherein the means for converting wind into usable energy converts the wind into mechanical or electrical power.

3. Means as claimed in Claim 2, wherein the means for converting wind into usable energy is a wind turbine or fan.

4. Means as claimed in Claim 3, wherein the wind turbine or fan is coupled to an electric generator.

5. Means as claimed in any of Claims 1 to 4, wherein the wind flume and the wind dam are formed at least partly by the walls of buildings.

6. Means as claimed in any of Claims 1 to 5, wherein the wind flume and the wind dam are formed partly by natural geographical features.

7. An integrated system for utilising solar energy and energy from wind comprising a combination of a means as claimed in any of Claims 1 to 6 with a means or apparatus for utilising solar energy derived from solar radiation.

8. A system as claimed in Claim 7, wherein the means for utilising solar energy from solar radiation comprises a plurality of parallel strip lenses to concentrate solar radiation into a series of parallel bands and means for converting the radiation into usable form located approximately at the focal length of the strip lenses where the radiation is concentrated.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. to leave out one or more of the features described, as dictated by the requirements and investment capital available. For example, the heat pump assembly, and the refrigeration facilities could be omitted. Example 3 This Example describes one possible modification of the heat collector plate assembly 1, described and shown in Figure 1, and utilised for instance in Examples 1 and 2, which permits the use of the solar radiant energy for the production of electric energy as well as the production of hot water at a higher temperature. This modification is illustrated in Figure 4. Groups of three parallel strip lenses are moulded into the plastics cover plate, with each outer lens in the group being set at such an angle to the central lens that the concentrated bands of solar radiant energy from each group are concentrated on a single conduit 5. The said angle is determined by the focal length of the lenses. The pattern of said groups of three lenses so inclined to one another is repeated across the whole cover plate. The said conduits are manifolded together by piping system 12, the inlet being fed by pump 8 with a suitable low boiling point fluid, which is vapourized in said heated conduits 5, the vapours from the outlet manifold driving a turbine 29 which is coupled to an electric generator 11. The exhaust of said vapours from the turbine 29 are condensed in heat exchanger 19, cooled by water fed in parallel with cold make-up water fed through line 20 and cool water from the bottom of hot water tank 13, the warm exit water being circulated by lines 17 back to the said water tank (Figure 4A). The conduits 5 can be substituted by rows of photovoltaic cells 35, for example silicon solar cells.As the solar energy concentrated by the triple combination of the strip lenses 2 can overheat and damage the said cells they are covered over by an hemispherical plastic dome, and cooled by blowing air through it by means of a blower and air piping (not shown). The heated air leaving the said domes 39, which are bonded to the collector plate base 7, is then used as a source of domestic heat. The heat collector assembly 1 (Figure 4) shows a module, forming part of the whole assembly, comprising only two conduits 5 and two rows of solar cells 35, but the whole assembly can contain as many of each as desired or alternatively comprise only conduits 5 or silicon cells 35 as desired. Example 4 This Examples describes one possible form for the utilisation of existing geographical features for the generation of wind power. The valley walls 4 and the rising floor of the valley 6, leading up to the pass 5, form a wind flume 1 which traps the wind force by means of a wind dam 2 built as a roof over the upper end of the valley. Windmills or wind turbines are installed at the apex of the valley 5, and utilise the wind force trapped to drive electric generators (not shown). The said windmills or turbines 3 exhaust the wind driving them into the open air 7 on the other side of the pass 5. The layout is shown, in simple schematic form, as a projection in Figure 5, with vertical sections shown in Figure SA at the entrance of the valley, and as Figure SB at the pass.Details will depend on the actual geographical features available, but the aim is that the area of cross section of the valley at the edge of the wind dam 2 should be as great as possible compared with that at the machines 3 at the apex. WHAT I CLAIM IS:

1. Means for recovering energy from wind comprising a wind flume and dam (as herein defined), and a means for converting concentrated (high velocity) wind into usable energy located approximately at the apex of the wind flume.

9. A system as claimed in Claim 8, wherein the means for converting the radiation into

usable form comprises one or more conduits through which a fluid is flowing, the solar energy radiation being absorbed by the fluid which is heated thereby.

10. A system as claimed in Claim 9 wherein the fluid contains in solution a dye suitable for absorbing radiation or contains a black powder in suspension.

11. A system as claimed in Claim 9, wherein the dye is a black dye.

12. A system as claimed in Claim 9, wherein the black powder is graphite.

13. A system as claimed in any of Claims 9 to 12, wherein the fluid is water, anti-freeze solution or a heat transfer fluid.

14. A system as claimed in any of Claims 9 to 12, wherein the fluid is a gas.

15. A system as claimed in Claim 14, wherein the gas is air.

16. A system as claimed in Claim 8, wherein the means for converting the radiation into usable form comprises one or more rows of solar cells for converting the radiation into electrical energy.

17. A system as claimed in Claim 16, wherein the solar cells are cooled to permit use of a higher concentration of energy without damage to the cells.

18. A system as claimed in Claim 17, wherein the solar cells are cooled by a stream of cooling air conducted over them through a conduit transparent to solar rays.

19. A system as claimed in Claim 17 or 18, wherein the solar cells are cooled by a liquid refrigerant from a heat pump circuit as it evaporates before being compressed and recycled.

20. A system as claimed in any of Claims 8 or 19, wherein two or more strip lenses are inclined relative to one another at an angle such that the bands of concentrated solar radiation from these strip lenses are superimposed on one another and are focussed on the same means for converting the radiation into usable form.

21. A system as claimed in any of Claims 8 to 20, wherein the means for converting the radiation into usable form is provided with at least one heat or light sensing device and means are also provided for moving either the means for converting the radiation into usable form or the strip lens assembly so that the bands of concentrated solar radiation remain in register with the means for converting the radiation into usable form despite the motion of the sun.

22. A system as claimed in claim 21, wherein the means for moving either the means for converting the radiation into usable form or the strip lens assembly comprises a servo-motor and mechanical linkages or a mechanical device and linkages actuated by differential metal expansion on heating.

23. Means for recovering energy from wind as claimed in Claim 1, substantially as described with particular reference to any of Examples 1, 2 or 4, or Figures 2, 3 or 5 of the accompanying drawings.