FIELD OF THE INVENTION

The invention relates to photovoltaic energy generation, particularly on small surfaces, and more specifically to solar electric generation in small concentrator units with vertically arranged stacks of solar cells, embedded in a heat transfer medium.

BACKGROUND OF THE INVENTION

-Energy reeovery-on small-areas, as on ars and airplanes, getto Lbe_mandatQry__ for keeping up the charging of storage means.

Particularly electric and hybrid cars rely on batteries that need to be loaded and the charging be sustained. Solar energy can do a good part of it - particularly for the latter - if high efficiency compensates for the limited amount of impinging light.

PROBLEM TO BE SOLVED

Suitable solar cells with high recovery rates, as such with aluminium-gallium arsenide alloys, tend to be sensitive to overheating and therefore are critical in combination with concentrator units.

The inventive step in the here disclosed invention therefore is to design the array in a way, which would combine highly efficient optical concentration of impinging light from all surrounding directions, as well as cooling the solar cells efficiently by heat transfer to a greater surface.

PRIOR ART

There had been some solutions disclosed for arranging solar cells, which could be applied to irregular curved surfaces, as in US 4.311.869, whereas it will be difficult there to arrange the reflecting means effectively due to changing curvatures.

Single concentrator units, as in US 2009 231 739 (Al), are as well known, but not meant for building up clusters of small units - moreover in this case are impractical for layups on whatever kind of surface, due to its open structure.

Moreover, quite a few solar arrays are known, having multiple single solar cells and concentrators, mostly Fresnel lenses, as in US 5.123.968, or combination of Fresnel and conventional lenses, as in US 6.804.062 B2, or mirrors and lenses as in WO 03/054317 A2 - but none of those suited for mounting it on curved surfaces.

Other possible solutions, like thin-film solar cells mounted on flexible wire bases, as known from Odersolar (www.odersolar.de) have lower efficiency, which is particularly disadvantageous, when only small surfaces can be applied for energy recovery.

SUMMARY OF THE INVENTION

For to overcome the afore mentioned problems, the here disclosed system comprises a parabolic lentil concentrator for gathering light from all directions to direct it to an stack of embedded solar electricity converting chips.

Each single unit is relatively small (radius is about 20 mm) and therefore can be mounted on curved surfaces.

Said chips are interconnected by a tiny scaffold of electric wires, that connects the electrical current from each unit through to a base grid of pins, that can be plugged into a printed board.

Thereon electric components may be arranged to interconnect and transform the resulting electrical current as to the required purposes .

In quite some cases, as e.g. when mounting these units onto metal bodies of cars and airplanes, the printed board may be replaced by electrically insulating materials of high heat-transfer rates, like Ceramics as A1203, so to use the body for further heat dissipation.

However, the parabolic shape of the encapsuling lens system already offers a surface that will be about 200 times the light-impinged surface and therefore will provide good heat dissipation.

Moreover, the medium itself -be it water, highly transparent industrial oil or gels- will buffer and disperse the punctually concentrated thermal energy, whereas the conditioning of the lenses surface will bloc the infrared component of incoming radiation, which is not suited for energy conversion within these kinds of solar cells. DESCRIPTION OF THE INVENTION ALONG TO THE DRAWINGS

Fig. 1 shows the lens body 1 together with three vertically stacked targets 2, 3 , 4 with basic incidence of light 5 from one side. As to optical laws, the light entering the top third of the parabolic lens 6 is directed to the top target 2, whereas the middle section incidence 7 is guided to the middle target 3 and the low section 8 to the low target 4 - whatever their horizontal angle of impingement may be.

The targets 2, 3, 4 are interconnected by a scaffold of electrical wires 9, that lead to a printed board 10 , comprising connecting pins for further wiring.

Fig. 2 demonstrates the distribution of light coming from different vertical directions 5 - 9. It s seen, how these are as well efficiently directed to the three stacked targets 2 - 4.

Fig. 3 shows exemplarily the mounting of above mentioned chips 2-4 for an inverted system, that used the parabolic shape as a mirror 10 to concentrate plainly entering light 11 to the afore mentioned three targets 2-4.