To determine how many kilowatts a strip light fixture with fluorescent bulbs uses depends on how many bulbs are being used, their size, and wattage. For example, a 4-foot strip light fixture with (2) 32W T8 fluorescent bulbs uses 0.064kW. To get that number you take the total wattage of the strip light fixture, which was 64 watts and divide that number by 1,000 (which equals 1kW).