Construction block with photovoltaic device

Transparent blocks used in buildings to form internal partitions or sections of external walls that allow the transmission of light, are typically made from glass, as either solid or hollow blocks – the latter providing reduced weight and material cost. Elements such as photovoltaic panels or cells incorporated into glass blocks, may prevent the transmission of light. Solar collector devices, however, enable photovoltaic devices of smaller dimensions to be used, enabling a portion of light to pass through the block while also generating electricity. In addition to admitting light into the building, it is desirable for transparent blocks positioned at an exterior wall to provide good thermal insulation properties.

In January 2020, University of Exeter was granted UK patent 2561369, titled Construction block with photovoltaic device, which disclosed a construction block intended for use in the formation of light transmitting sections of walls in buildings. The block (10) comprises an input wall (16) and an output wall (22), spaced apart forming a void (32). The input wall has a plurality of projections (18) extending toward the output wall, serving to disrupt convection currents forming in the void. At least one of the projections comprises a solar concentrator which has a photovoltaic device mounted to it. The projections extend to positions spaced from the input wall by 3060⁰/0 of the spacing between the input and output walls.

In a preferred embodiment, the block comprises a front section (12) and a rear section (14) of moulded glass that defines the input and output walls respectively. Around the input wall, which faces the exterior of the building, is an integral peripheral wall (20), with another at the rear section (24). The peripheral walls are spaced inwardly from the edges of the input and output walls, forming a shallow channel (26) that extends around the block.

In the arrangement illustrated, each of the projections takes the form of a solar concentrator, shaped to include a circular input side (18a), a square output side (18b), and side walls of curved, hyperbolic form extending between input and output sides. The shape of the projections is such that light incident upon the input side undertakes multiple internal reflections and is concentrated upon the output side.

Mounted upon the output side of each projection is a photovoltaic device (28) arranged such that light incident thereon is used to generate electrical output. Conductors that interconnect the devices may be provided to supply the electrical output, via an opening formed in the output wall, to the exterior of the block.

In use, where a light transmitting wall section is constructed using a block, some of the light incident on the input wall will be transmitted to the output wall resulting in light entering the building. Additionally, some of the light incident upon the input wall – in the regions of the input sides of the projections – will be incident upon the photovoltaic devices, resulting in the generation of electrical output from the block via conductors. Thus, the block allows for the building to be illuminated while also generating electricity.

The projections extending from the input wall serve to disrupt the formation of convection currents in the air and within the void. Thermal energy losses between the input and output walls are thereby reduced, enhancing the thermal insulating properties of the block. Optionally, the projections may be arranged to achieve a desired design or visual appearance, e.g. to form lines or patterns. The projections may have a coloured material element mounted thereon making the block appear to have one or more coloured regions.

Read the full patent here