A reader asks:

 Have you been able to determine how many kilowatts the 10,000 lux device uses? Specifically, how much electrical cost will daily 30-minute usage add to my electric bill?


Our engineering consultant advises: Most 10,000 lux systems with diffusion covers use about 125 watts / 120 volts of energy for a 30-minute exposure, or 0.125 of one kilowatt (=1000 watts) per session. So, math follows, 0.062 kilowatt/hour (kwh) per treatment. In other words, 1 kwh would covers 16 sessions and 2 kwh would get you through the month’s billing period. If you’re paying 7 cents per kwh, the total cost would be 14 cents. Not bad, eh?!