Energy efficient loads

An off-grid PV system is sized and designed based upon the loads (lighting and appliances) that will be used with the system and the amount of time that they will be operated. The most commonly uses for an off-grid PV system are for lighting, cell phone charging, radios, televisons, fans and refrigerators. The majority of these types of appliances in the market are conventional, meaning that they are not appropriate for use in off-grid applications. Lighting and appliances that are appropriate for use in an off-grid application are designed to be more efficient. Increasing efficiency does not mean decreased performance as there are cases - like with incandescent and LED bulbs - in which one design simply loses significant amounts of energy as heat or to friction. In addition, energy efficient appliances do not necessarily have to cost more than conventional appliances, but they can have a significant impact on the cost of the system by reducing the size of the PV source and energy storage system. Energy efficient appliances are available in both alternating current (AC) and direct current (DC), although DC appliances are inherently more efficient as there are no efficiency losses resulting from passing through an inverter.