Solar cell produces DC electric energy. For solar cell system, where the solar cell array has radius not more than 100-m to batteries and electrical loads, it is effective and cost efficient to be connected by DC buss system. By using DC buss system, in order to transfer electrical energy from solar cells to batteries and loads, the parameter needs to be considered is voltage. The DC buss is the most efficient and cost effective, since it does not require electrical conversion from DC to AC. DC buss can be extended for more than 100-m, even can be more than several kms. In order to lower the DC electric power loss in the transmission from solar cells to batteries and loads, the DC transmission voltage should be increased, hence, to deliver the electrical power it requires only a very low current. This method is very popular used in AC electric transmission for long distance by using high voltage AC. The DC electric power transmission loss is written by the following equation:
PL = I2D cRr (4)
PL is power loss in the DC transmission line, Rtr is the total transmission line resistance and IDC is the DC current on DC buss transmission line. Hence, to lower power loss and Rtr kept same, then IDC must be decrease much lower with consequence of VDC must be increase proportionality to the decrement of IDC. To increased voltage VDC, in general conducted by using boost converter method.