Line-focus photovoltaic module using solid optical secondaries for improved radiation resistance

DETAILED DESCRIPTION We have devised a novel line-focus tandem-cell electric power supply integrating a new durable, low-cost line-focus, arched Fresnel lens and a unique line-focus, radiation-resistant tandem-cell receiver.
Like the domed lens, the novel arched line-focus Fresnel lens consists of a silicone rubber grooved inner surface and a glass superstrate.
However unlike the domed lens, the arched glass superstrate can be bent flat and the silicone grooves molded directly to the flat glass without interlocking prisms in the mold.
Therefore, this line focus lens is inexpensive to make in a space-survivable form.
Given this line-focus lens, the problems to be solved for the tandem-cell receiver are, first, to provide for the additional leads associated with a tandem cell-stack, and second, to provide for a higher concentration ratio in order to make the cells low-cost and affordable.
These two problems are solved by using a solid optical secondary with a rectangular entrance aperture bonded to the top cell in the tandem cell-stack.
All of the light arriving at the line focus receiver is then collected when the optical secondary rectangular entrance aperture on one cell-stack is butted up against the adjacent optical secondaries in a receiver cell string.
This scheme has three advantages.
First, it leaves area at the base where two optical secondaries join for tandem cell leads.
Second, the use of an optical secondary in this scheme also increases the concentration ratio, thereby making the cells more affordable, and third, the optical secondary covers the cell-stack, providing for radiation shielding of the cells.
The objectives of this invention are to produce a high performance module which is low-cost, durable, and usable in a large number of space missions.
The resultant line-focus tandem-cell module has a performance comparable to the mini-domed lens module since it operates at the same concentration ratio and incorporates the same tandem-cells.
It is durable because the arched lens is now manufacturable with a protective glass superstrate