Sol3g - Third Generation Solar Systems

Technology

Photovoltaic solar systems directly transform solar light into electrical energy through a solar cell, by using the photovoltaic effect.

Sol3g uses an optical concentration system that concentrates the solar light in a much smaller area of solar cell. Few semiconductor material is used - the semiconductor surface is 400 times smaller than that of a traditional crystalline silicon flat panel - with the consequent cost saving.

It has been designed a 2 components optical system that provides a geometric concentration of 476 suns (1) along with a high deviation tolerance.

Sol3g uses tandem triple junction cells, consisting of a stack of cells of different composition with a progressively decreasing bandwidth, so that the cells in the top of the stack absorb higher energy photons than those of the bottom part.

These cells are made by MOCVD (Metal Organic Chemical Vapor Deposition) with groups III-V compounds (InGaP and AsGa) deposited on a germanium substrate. They resist the concentration of the radiation very well and have an efficiency of around 35%, much higher than traditional silicon cells.

These cells offer a double advantage:

—Get the most out of the solar spectrum obtaining a greater conversion efficiency;

—They perform better when operating at high concentrations (300 to 500 suns), obtaining that the cell works at a temperature of 10 or 15° over the ambient temperature.

Full technical sheet (PDF)

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(1) Concentration is a geometric relation between the collection surface or the solar aperture and that of the photovoltaic cell (a concentration of 100 suns means that the collection surface or the solar aperture is 100 times greater than the cell surface), understanding high concentration a concentration ratio greater than 100 suns.