kWh is the abbreviation for kilowatt-hours. A kWh is the basic unit of solar electricity used worldwide. If you are consuming 1,000 units of electricity every month, you are consuming 1,000 kWh a month. A watt-hour (Wh) is the amount of solar electrical energy a power system of 1 watt can generate in one hour. One kilo-watt hour, equal to 1,000 Wh, is the amount of electrical energy that a 1 kW system operating at peak capacity can generate in one hour.