A solar power system, comprising: DC power from a solar energy source ; at least one dual mode buck-boost photovoltaic DC-DC converter to which said DC power is input; converter functionality control circuitry configured to control said at least one dual mode buck-boost photovoltaic DC-DC converter; a converted DC output from said at least one dual mode buck-boost photovoltaic DC-DC converter; and a load to which said converted DC output is input, wherein, in any order, a first mode is capable of creating an output voltage that is lower than an input voltage and a second mode is capable of creating the output voltage that is higher than the input voltage; wherein said dual mode buck-boost photovoltaic DC-DC converter comprises at least one pair of input semiconductor switches (T21, T22) , an input series inductor, an input parallel capacitor, at least one pair of output semiconductor switches (T23, T24), and output series inductor, an output parallel capacitor, and at least one capacitor configured in parallel between said input semiconductor switches and said output semiconductor switches, one of each pair of semiconductor switches (T21, T23) being a series switch and the other (T22, T24) being a shunt switch, wherein said converter functionality control circuitry is configured to control said switches in a variable duty cycle to achieve the desired functionality, wherein said input parallel capacitor is connected to said input series inductor, and said input series inductor is connected between said at least one pair of input semiconductor switches; wherein said output parallel capacitor is connected to said output series inductor, and said output series inductor is connected between said at least one pair of output semiconductor switches. DC power from a solar energy source ; at least one dual mode buck-boost photovoltaic DC-DC converter to which said DC power is input; converter functionality control circuitry configured to control said at least one dual mode buck-boost photovoltaic DC-DC converter; a converted DC output from said at least one dual mode buck-boost photovoltaic DC-DC converter; and a load to which said converted DC output is input, wherein, in any order, a first mode is capable of creating an output voltage that is lower than an input voltage and a second mode is capable of creating the output voltage that is higher than the input voltage; wherein said dual mode buck-boost photovoltaic DC-DC converter comprises at least one pair of input semiconductor switches (T21, T22) , an input series inductor, an input parallel capacitor, at least one pair of output semiconductor switches (T23, T24), and output series inductor, an output parallel capacitor, and at least one capacitor configured in parallel between said input semiconductor switches and said output semiconductor switches, one of each pair of semiconductor switches (T21, T23) being a series switch and the other (T22, T24) being a shunt switch, wherein said converter functionality control circuitry is configured to control said switches in a variable duty cycle to achieve the desired functionality, wherein said input parallel capacitor is connected to said input series inductor, and said input series inductor is connected between said at least one pair of input semiconductor switches; wherein said output parallel capacitor is connected to said output series inductor, and said output series inductor is connected between said at least one pair of output semiconductor switches. <EOS>