The present invention relates to a solar canopy.

A solar canopy is a lightweight structure with solar panels incorporated into the roof. Such canopies are useful for distributed power generation.

Canopies may be used in a number of applications, for example, as an event shelter. In particular, they are increasingly being used as carports. With the rapidly increasing popularity of electric vehicles, solar carports provide an environmentally friendly way of generating energy to recharge the vehicles. These can either be used in a domestic environment or a car park where they can generate electricity for a number of parked vehicles. The canopy may be associated with an energy store such as a battery or flywheel.

The present invention is directed to a solar canopy which is significantly cheaper than prior art structures whilst still being able to provide a structure which can generate the levels of power required for an application such as a carport.

According to the present invention there is provided a solar canopy according to claim 1.

The solar cells having a inclined support with one or more strips of flexible solar material on the upper surface provides a lightweight solar generating cell. These cells can be supported on a frame which can be a lightweight structure in view of the reduced load that it needs to support by comparison with conventional solar panels.

Further, the cells provide a modular structure allowing a solar canopy to be designed to fit the space available and/or the required power output. This can easily be scaled up just by varying the size of frame.

Further, because the solar cells have strips of flexible solar material running across them and are shaped to be mountable in more than one orientation at each support site within the frame, the orientation of the solar strips can be arranged to maximise the solar generation depending upon the location of the canopy. In particular, as the sun tracks across the sky from east to west, maximum generation can be provided by the strips of solar material if they are positioned to face in a direction which is generally south in the northern hemisphere and north in the southern hemisphere.

The inclined support may be a planar support which is mounted at an angle to the frame. However, preferably, the inclined support is provided by the support being curved. The curved support may also be mounted at an angle to the frame to optimise the ability to mount the cell for optimum generation throughout the day. The support may not be truly curved but may be a plurality of flat portions arranged at a slight angle to one another to approximate to a curved support.

The curved support can be configured to provide more uniform generation throughout the day as the strips of solar material can be positioned at different angular orientations so that each individual strip can provide optimal generation at a different time of day, and shadowing effects of one cell on another can be reduced.

The shape (i.e. footprint) of the solar cell may be any shape which allows the cell to be mounted in more than one orientation at the same site. It could, for example, be circular to allow infinite variation. However, this would create a significant gaps between adjacent cells and is not straightforward to produce. Preferably, therefore, the solar cells have a polygonal and tessellating shape such as a triangle or hexagon. More preferably, the solar cells are rectangular and most preferably square. A rectangular shape is simple to manufacture, for example, from a reel of material providing the support to which strips of solar material can be adhered. If the solar cells are square, this allows them to be mounted in four different orientations as opposed to two orientations for a non-square rectangular cell.

In its simplest form, the solar cell may be curved in a single sense. This can be achieved simply by bending the support in a single sense. In such a structure, each strip of flexible solar material preferably extends along, as opposed to across, the curved support.

For a more complex design, the solar cell may be curved in two senses thereby creating the dome-like structure. With such an arrangement, each strip of flexible solar material will be curved given the curved nature of the underlying support.

A strip of flexible solar material can have a constant radius of curvature. Alternatively, however, the radius of curvature can be varied, in order to optimise solar generation. For example, the radius of curvature of a strip of solar flexible material can decrease from one end to the other and the solar cell can be mounted such that the region with the smallest radius of curvature is mounted uppermost. This effectively provides a solar cell with a relatively gentle curvature at its lowermost end and an uppermost end which levels off closer to a horizontal plane.

The properties of the solar material can be optimised to absorb radiation of a particular wavelength. The material properties can therefore be optimised to match the optimal absorption wavelength for a particular position of the material on the support. For example, a part of the solar material positioned to capture a greater proportion of the solar radiation early or late in the day may be configured to absorb more radiation at higher wavelengths of the available spectrum. On the other hand, a part of the solar material positioned to capture a greater proportion of the solar radiation towards the middle of the day may be configured to absorb more radiation at lower wavelengths of the available spectrum. These properties can be configured to vary along each strip and/or may be different from strip to strip.

As a simple way of forming and supporting a structure which is curved in two planes, the support may be provided as an inflatable structure, one face of which provides the upper surface to which the flexible solar material is attached. This provides a low cost way of supporting a curved structure which does not require a peripheral frame in order to maintain a curved structure. Further, the air within the inflatable structure will be heated by sunlight which raises the temperature of the flexible solar material which improves energy generation.

The present invention also extends to a kit of parts for creating a solar canopy, the kit comprising: a support structure comprising a frame defining a grid of support sites; a plurality of solar cells, each cell having a support which is inclined with respect to the frame supporting at least one strip of flexible solar material, on an upper surface of the inclined support; wherein the solar cells are shaped such that they can be mounted in more than one orientation at each support site. The kit may have any of the above preferred features.

Examples of solar canopies in accordance with the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic perspective view of a canopy showing solar cells in different orientations;

Figure 2 is a perspective view of a first example of a solar cell;

Figure 3 is a cross section of a second example of a solar cell; and Figure 4 is a cross section through a plurality of solar cells of a third example.

As shown in Figure 1 , the support structure 1 comprises a frame 2 made, for example, of lightweight steel. The frame 2 defines a grid of support sites 3 which have the same shape and size. The single shape of solar cell is the most straightforward to manufacture. Flowever, any number of different shapes of solar cell can be used to generate more complex shapes of canopy (e.g. there could be some square cells and some triangular cells). Any such additional solar cells could also have the ability to be mounted in more than one orientation. Flowever, if there are a relatively small amount of such additional cells, this may not be necessary. Further, it is possible that the solar canopy has the majority of its structure covered with solar cells, but has some other regions which are not provided with solar cells if this required for aesthetic reasons and it is not economic to apply solar cells in certain regions.

As shown in Figure 1 , the support structure 1 is supported by a plurality of legs 4 which support the support structure 1 above the ground. In other implementations, the support structure may be supported in other ways, for example, being supported across a gap between the existing supports such as walls.

Figure 1 schematically depicts two solar cells 5, each having a plurality of strips of solar material 6 as described in greater detail below. As shown in Figure 1 , these solar cells 5 are mounted in different orientations. The left hand cell 5 is mounted with the strips of solar material 6 extending in a first direction, while the right hand cell 5 is the same cell, but rotated through 90* with the flexible solar strips 6 being orthogonal to those of the first solar cell. In practice, all of the strips in a single support structure should be oriented in the same direction as the optimal orientation is determined by the geographical location of the canopy and the position of the canopy with respect to the direction in which the sun transverses across the sky. For the avoidance of doubt, although the solar cells can be mounted in several orientations, the solar cells are preferably fixed in a single orientation and the orientation of the solar cells is preferably uniform across the support structure 1. A first design of a solar cell is shown in Figure 2. This comprises a curved support 7 to where three strips of flexible solar material 6 are attached. The support 7 is curved in a single plane so that its surface has the shape of part of a cylinder. The material forming the support 7 may be sufficiently rigid to maintain the curved shape under its own weight, or may be supported in the surrounding frame which biases it into the curved position. In its simplest form, the solar cell may just comprise the support material and the flexible solar material. This may also simply be supported entirely by the frame 2. Alternative, the solar cell may be provided with its own cell frame which supports the flexible support such that this cell frame can be fitted in place in the support frame 2. The frame for the solar cells may be higher at one end than the other to allow the solar cell to be supported in an inclined manner within the support frame orientations. Optimally, the cell would be mounted so that the span runs in an east/west direction with the strips 6 running north/south. The southern end is mounted lowermost and the northern end uppermost.

A second example of a solar cell is shown in Figure 3. This comprises an inflatable cushion 8 of a flexible material such as ETFE (ethylene tetrafluoroethylene) which has an upper layer 9 and a lower layer 10 which are bowed in a convex position by an air pocket 11. The strips 6 of flexible solar material are attached to the upper layer 9. As shown in Figure 3, this example is shown as having a support frame 12 supporting the solar cell at an angle to the horizontal.

Figure 4 shows a further arrangement, this time showing a cross section through 4 adjacent cells 5 on the support frame 2. These cells have a curved support 13 which is curved in two planes thereby supporting strips of flexible solar material in a curved configuration. The support structure is attached to a frame 14, which, as with the second example, raises the right hand side of each solar cell with respect to the opposite side. As is apparent from Figure 4, the support 13 is configured such that it has a large radius of curvature on the left hand side which gradually decreases towards the right hand side providing an asymmetric curved structure to optimise solar generation.

The flexible solar material may be any flexile solar material such as amorphous silicon CdTe, CIGS, GaAs. Flowever, preferably, it is a thin film organic photovoltaic (OPV) material. The solar material will be provided with appropriate electrical connections in a conventional manner in order to allow the generated energy to be transmitted, for example, to a storage device.