Abstract: The invention provides photovoltaic concentrator solar cells and a method of forming these from a semiconductor wafer. The method has the steps of first doping the rear surface of said wafer so as to provide a first doped region. Depositing passivation layers on the front and rear surfaces. Forming a deep groove in the rear surface through the passivation layer and doping said rear surface so as to provide an oppositely doped second doped region in the deep groove. Then an opening is formed through the rear passivation layer to the first doped region; and electrical contacts are formed on the rear surface to electrically connect to the first and second doped regions. The photovoltaic concentrator solar cell has a semiconductor wafer with a passivation layer deposited on front and rear surfaces; and a first doped region at the rear surface.

Abstract: The invention provides photovoltaic concentrator solar cells and a method of forming these from a semiconductor wafer. The method has the steps of first doping the rear surface of said wafer so as to provide a first doped region. Depositing passivation layers on the front and rear surfaces. Forming a deep groove in the rear surface through the passivation layer and doping said rear surface so as to provide an oppositely doped second doped region in the deep groove. Then an opening is formed through the rear passivation layer to the first doped region; and electrical contacts are formed on the rear surface to electrically connect to the first and second doped regions. The photovoltaic concentrator solar cell has a semiconductor wafer with a passivation layer deposited on front and rear surfaces; and a first doped region at the rear surface.

Abstract: A solar energy assembly for collecting and converting solar energy. It comprises a plurality of solar energy converters 36 and an equivalent number of solar concentrator lenses 39, each lens being associated with one energy converter 36 and being adapted to concentrate light onto that energy converter. The lenses may be separate from each other and may be mounted and replaced independently of the others. One or more panel 20 may be mounted on a support frame 21,22, each panel having a plurality of solar energy converters and a lens array adapted to focus light on to the solar energy converters. The lens array may have a lens mounting system 37,38,66,58 adapted to hold it the desired focal distance from the solar energy converters.

Abstract: A reflector 11 for directing solar radiation on to energy converters provided within a defined area 14. The reflector is arranged for location around said area with a lower edge 18 of the reflector positioned adjacent the periphery of said area, the reflector comprising a panel formed of a material substantially transparent to solar radiation and having a front face 24 on to which solar radiation is incident. Behind the front face, the reflector is formed to have a plurality of prismatic units 25 within which total internal reflection of radiation incident on the front face takes place. In use solar radiation incident on the front face of the reflector is reflected within the reflector by the prismatic units to be directed on to the energy converters.

Abstract: The present invention provides an electrical vehicle battery system comprising a battery base unit (20) and one or more stackable supplemental battery unit (30) that may be joined thereto. The base unit (20) has a housing, an electrical storage cell within that housing, and mounting means (22, 23) to connect the base unit to the electrical vehicle and to provide electrical power. The base unit further comprises connection means (25, 35, 36) by which one or more supplemental battery unit may be attached to an upper surface of the base unit to supply electrical energy thereto. The supplemental battery unit has connection means (33, 34, 38, 40, 42) which cooperate with those of the base unit. Further equivalent supplemental battery units may be attached to the top of the supplemental battery unit (30). A load bearing surface (21, 31) is defined by the battery system thereby to support cargo on the vehicle.