This invention relates to a solar energy conversion device.

The object of the present invention is to provide the solar energy conversion device which has photoelectric elements arranged in predetermined position so as to permit efficient conversion of solar energy into electric energy. The object of the invention is achieved by having at least three arrays of photoelectric cells which have preferred fixed orientations and a particular ratio of areas, whereby the device can be efficiently used over a wide range of latitudes and at different seasons of the year.

More specifically the present invention provides a solar energy conversion device comprising a support structure which includes a base and support means for supporting first, second and third arrays of solar energy conversion elements, the first array having a center line, the first array being supported relative to the base such that, in use, the center line extends substantially in the north-south direction and an elevation angle in the range from 0°

to 75°, the second and third arrays being supported on opposite sides of said center line and extending from the sides of the first array towards the base, the areas of the first, second and third arrays being approximately in the proportion 2:1:1.

It is preferred that the solar energy conversion elements comprise photoelectric cells. Alternatively, the elements may comprise heat absorptive pipes through which a heat transfer fluid such a water is passed.

It is preferred that the means for supporting the first, second, and third arrays comprises first, second, and third support surfaces on the structure, the support surfaces having predetermined orientations relative to said base.

It is further preferred that the structure comprises a truncated trapezoidal wedge.

The invention will now be further described with reference to the accompanying drawings, in which:

Figure 1 is a diagrammatic perspective view of a structure of the invention.

Figure 2 is a plan view of the structure.

Figure 3 is front elevation of the structure.

Figure 4 is a rear view of the structure.

Figure 5 is a cross-section along the line 5-5,

Figure 6 shows the shapes of the various panels which make up the structure.

Figure 7 is a rear view of a modified form of structure of the invention, and

Figure 8 is a rear view of further modified form of the invention.

The structure 2 illustrated in Figures 1 to 4 is erected from a number of panels including a base

panel 1, roof panel 4, side panels 6 and 8, front panel 10 and back panel 12. The back panel 12 is not shown in Figure 1 for clarity of illustration. The panels are rigid and can be made from any suitable material for building a structure. The panels are connected together using known building techniques and need not be described in detail. The structures 2 of the invention can be constructed in various sizes. It is envisaged that relatively small units could be made whereby the structure has the size of a shed or the like. Larger units could be made whereby the structure could be used as a dwelling and still larger structures could be built having sufficient size such that the structure could be used as a multi-storey building, office building, warehouse or factory.

In the arrangement of the invention, the roof panel 4 and side panel 6 and 8 support first, second and third arrays of photoelectric cells 5, 7 and 9 respectively. The arrays of cells are preferably substantially the same shape and size as the panels on which they are supported. Output leads from the cells would be directed to the interior of the structure whereby control equipment (not shown) is located for controlling the electrical output from the cells. The control equipment could simply comprise switch gear if a direct current output were required for instance for battery charging. Alternatively the control gear may include an inverter for producing ac output.

Figure 5 shows the preferred shapes of the panels which make up the structure. It will be noted that the roof panel 4 is square and has a side length L, or rectangular with length ratios up to 1:2

or trapezium with angles 45° to 90°. The side panels 6 and 8 are quadrilaterals having opposite sides parallel. The preferred lengths are 1.0 L, 0.24 L, 0.91 L and 0.8 L. The angle A between the sides of length 1.0 L and 0.8 L is in the range from 33 to 93° and preferably 63°. The front panel 10 is a quadrilateral having following lengths of sides 1.0 L, 0.24 L, 1.24 L and 0.24 L. The angle B between the sides having lengths 0.24 L and 1.24 L is in the range 45 to 90° and preferably 60°. The back panel 12 is also a quadrilateral. It has sides of the following lengths V. Q L, 0.8 L, 1.84 L and 0.8 L. The angles C between the shorter sides and the longer side are in the range 45 to 90° and preferably 60°. Turning now to Figure 5, the structures 2 are made so that the elevation angle D of the roof lies at a preferred angle, in accordance with the latitude of the site at which the structure is to be utilized. Figure 4 shows the elevation angles E of the side panels 6 and 8. The angle E is also preferably selected in accordance with the latitude of the site at which the structure is to be used. The roof panel 4 has a center line 14 which in use is oriented in the North-South direction, the front panel 10 facing north in the southern hemisphere and south in the northern hemisphere. As can be seen from Figure 1, the morning rays 21 of the sun will first impinge upon the array 9 of cells on the panel 8. As the sun rises towards its zenith rays 23 will impinge upon the arrays 5, 7 and 9. Later in the afternoon the sun's rays will impinge upon the arrays 5 and 7. In the late afternoon the rays 25 will impinge upon the array 7 on the panel 6. The shape and size of the arrays 5, 7 and 9 has been chosen for substantially optimum collection of solar radiation.

The area of cells on the roof 4 and side panels 6 and 8 is preferably in the range 2:1:1. With this distribution of cells it has been found that satisfactory levels of output can be obtained over most of the daylight hours at the place where the structure 2 is used.

It has further been found that if the elevation angle D is made 30°, the structure can be used over a relatively wide band of latitudes from 10° to about 45° (in both hemispheres). For use near the equator, the angle D is preferably 0 to 15° and a structure so made can be used over a relatively wide band of latitudes from 0 ^β to about 30°. If on the other hand the angle D is made 60°, it can be used in polar latitudes say from about 60° to about 80°. In the structure of the invention, the difference between the angle of latitude of the site where the structure 2 is to be used and the angle D (called "bias angle"), if positive, yields higher electrical output during summer, and, if negative, yields a higher electrical output during winter.

Figure 7 shows schematically a rear view of a modified form of structure 30 in accordance with the invention. In this arrangement, intermediate panels 32 and 34 are located between the side wall panels 6 and 8 and the roof 4. The side wall panels 32 and 34 can be triangular or rectangular in shape. The orientation of the panels 32 and 34 is chosen to be generally intermediate of the orientations of the side wall panels 6 and 8 and roof 4, as shown in Figure 6. Photoelectric or absorber elements can be mounted on the intermediate panels.

The number of panels can be varied in accordance with the climates. Indeed it would be

possible to have a multiplicity of panels or even a structure having a part circular profile as illustrated by the structure 36 of Figure 8. The upper surface 38 of the structure preferably comprises part of a truncated conicallor cylindrical surface. Alternatively, the structure may comprise a part spherical surface. Photoelectric or solar absorber elements can be mounted on the surface 38. It is preferred that the angle E which is the angle of the tangent at the base is selected in accordance with the principals which have been discussed in relation to the previous embodiments.

The devices of the invention can be used to produce electric or heat energy. In addition they can be supplemented by other energy sources such as the output from additional cells, wind generators, or small scale hydroenergy systems which utilize the gravitational potential of water. In addition the units can be used for solar fuel production such as hydrogen gas from solar dissociation of water.

The structures of the invention can be mounted on a trailer or truck so as to be substantially portable. Alternatively the structures can be self contained so that they can conveniently be moved from one location the another.

Many modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention.