We are offering here the CVCF Panel that is a device that converts direct current (DC) electricity, which is what a solar panel generates, to alternating current (AC) electricity, which the electrical grid uses. The Constant voltage means that voltage instead of the amperage the LED sees always stays constant. The constant voltage driving characteristic is that the output voltage is fixed, and the current is limited to the maximum value with the change of the lamps and lanterns. CVCF Panel is very efficient.