kBtu: One thousand (1,000) British thermal units.
Kilowatt (kW): A unit of measure of the amount of electricity needed to operate given equipment. On a hot summer afternoon, a typical home, with central air conditioning and other equipment in use, might have a demand of four kW each hour. A unit of energy equivalent to one thousand watts.
Kilowatthour (kWh): A unit of energy that measures the amount of power produced or used over a one-hour time interval. A 100-watt light bulb operating for ten hours would use one kWh of energy. A unit of energy equivalent to one thousand watthours.