Solar power systems employ photovoltaic cells to convert the radiant energy of sunlight directly into electrical energy. Photovoltaic solar cells are semiconductor devices which convert sunlight into electricity. Solar cells which utilize crystalline semiconductors, such as silicon, offer the advantages of high performance and reliability. Photovoltaic cells are silicon-base crystal wafers which produce a voltage between opposite surfaces when light strikes one of the surfaces, which surface has a current collecting grid thereon. The photons of the light are absorbed by photovoltaic cells and yield their energy to the valence electrons of the semiconductor and tear them from the bonds that maintain them joined to the cores of the atoms, promoting them to a superior energetic state called conduction band in which they can move easily through the semiconductor. Typically, a plurality of solar cells are assembled and interconnected so as to form a physically-integrated module, and then a number of such modules are assembled together to form a solar panel. Several solar panels may be connected together to form a larger array. The individual photovoltaic cells in a module may be connected in series or parallel, typically by an internal wiring arrangement and similarly two or more modules in a panel may be connected in series or parallel, depending upon the voltage output desired. Solar cells are usually interconnected into series strips by electrically interconnecting a collector pad on the grid to the opposite surface of the adjacent cell in the strip. Photovoltaic cells are manufactured in a variety of configurations, but generally comprise a layered structure on a substrate. There are many different types of converging solar cell modules in which sunlight is converged by means of a lens system so that the total area of expensive solar cells can be reduced in order to reduce the cost of electric power generating systems using these solar cells. In order to most efficiently use the electrical power generated by a photovoltaic cell or photovoltaic array, it is desirable to maximize the power generated by the photovoltaic cell or photovoltaic array, despite varying weather conditions. Various sun tracking systems have been used to enhance the power generating efficiency of the converging solar cell module.

A solar energy battery is different from the regular battery. The solar battery module is constructed by having a multiplicity of solar battery elements carried on a supporting base plate. When the sunlight impinges on the individual solar battery elements, the energy of the light which makes no contribution to the photoelectric conversion is accumulated in the form of heat to elevate the temperature of the solar battery elements and lower the efficiency of photoelectric conversion. A solar cell having a photoelectric conversion layer in which at least one PIN junction is formed using a amorphous or microcrystalline silicon film is utilized. A solar battery converts light into electrical energy, its P-N junction structure when exposed to incident light generates large quantities of electron-hole pairs, and in the meantime electrons carrying negative electricity and holes carrying positive electricity migrate to the N-type semi-conductor and P-type semi-conductor respectively. This process produces electricity. In such converging solar cell modules, converging solar cell elements each having solar cells and their electrodes for outputting electric currents are used. When a spot formed by converged sunlight irradiates the light receiving surface of the converging solar cell, free electrons and electron holes as carriers are generated inside a silicon substrate. The photoelectric conversion efficiency of a solar battery depends mainly on the internal resistance of the solar battery. In particular, it depends on the series resistance of the upper and lower electrodes, and the series resistance of the elongation of the upper and lower electrodes which are brought into contact with each other in order to connect adjacent generating regions.

A typical solar battery comprises a glass substrate as a front side transparent protective member at a light-receiving side, a back side protective member, ethylene-vinyl acetate copolymer (EVA) films as sealing films arranged between the glass substrate and the back side protective member, and solar cells or silicon photovoltaic elements sealed by the EVA films. A solar battery module is generally composed of a solar battery panel comprising a light-transmission panel and a solar battery element, the solar battery element being provided on the surface which is opposed to the light-receiving surface of the light-transmission plate, and a frame for fixing the solar battery panel thereon. Solar panels have a large number of solar cells which are used to convert power from sunlight. Power generated by the solar cells is coupled via electric lines to a rectifier for feeding into the alternating current (AC) network or to a battery. A connecting box is generally provided for coupling to the solar panel. Solar panels are comprised primarily of a strongback, insulation, receiver tubes, headers and tube guide/supports. Tubes are connected at the top and bottom of the panel by the headers. Solar panels are typically mounted on a mounting structure, which is supported on a mounting surface, such as a rooftop. The sun's thermal energy is intercepted by a collector system that is comprised of thousands of sun tracking mirrors called heliostats. This energy is redirected and concentrated on a heat exchanger, called a solar receiver. The receiver includes a plurality of solar receiver panels positioned around an outside wall of the receiver. A solar battery module panel has a plurality of photovoltaic elements resin-sealed between a surface cover glass and a back cover film. In the case where several modules are to be interconnected, and also in the case where two or more solar panels are to be interconnected, external terminals are required for connections to cables that couple the modules or panels together.

Solar batteries have been used in various electronic equipment as power supply substitutes for dry batteries. Such batteries are highly reliable, have a long life, and now are economically produced. Initially, large-surfaced solar cell arrangements are used in photo-voltaic systems, for example, which can provide sufficient energy for consumers with a higher demand. Solar panels are particularly well suited to situations where electrical power from the grid is unavailable, such as in remote area power systems. Low power consumption electronic equipment such as electronic desktop calculators, watches, and portable electronic equipment (e.g., digital cameras, cellular phones and commercial radar detectors) can be fully driven by the electromotive force of solar batteries.