Concentration photovoltaics (CPV) energy is a type of solar energy whose development has increased in the recent years. Its main purpose is to reduce the quantity of semiconductor material used in a photovoltaic system as it is very costly. It is proposed to use instead optic elements (lens, mirrors…), lower cost, to achieve the same electricity production.

Why is it called ‘concentration photovoltaics’? Because these optic devices allow concentrating the solar radiation over a photovoltaic cell of small size, but with higher efficiency compared to the traditional silicon cells.

In the following image, it can be seen the difference between a flat photovoltaic panel (left) and a concentration photovoltaics system using a Fresnel lens (right) in order to concentrate the same solar radiation over a smaller photovoltaic cell.

 fresnel    Funcionamiento de una lente de Fresnel         

                   

Photovoltaic cells used in CPV are rather different from the cells used in flat panels since they must endure higher radiation density (the light output that reaches the cell is the same, but the surface is smaller). They are multi-band cells and are made of several semiconductor layers which form p-n unions between them. The different layers are aimed at covering a wider range of solar spectrum compared to the silicon cells one. Thus, it is achieved much higher efficiencies (40% vs. 18%).

However, there is another feature to be taken into account. As they are optic systems (that is to say, they have an optical alignment), it is necessary that they track the Sun throughout the day so that the optic surface (lens or mirror) is always perpendicular to the solar radiation. This tracking is an added cost for this technology, but without it, the CPV system would not generate electricity because the light would not be concentrated in the cell.

Concentration photovoltaics energy is a wide area with considerable technological advances.

 

 

Cookies make it easier for us to provide you with our services. With the usage of our services you permit us to use cookies.
More information Ok Decline