Bests & Worsts Reviews from Amazon

I just set up my new 10" x 20" pad and measured the conditions and power usage for about 24 hours. Conditions: Ambient temp = 63F On kitchen counter top Towel under pad Towel between pad and starter tray Measurements: Duration = 23 hr, 22 min Soil temp @ seed location = 76.8F Pad temp = 114.8F Current = 174 mA (0.174 Amps) Power usage = 21.15 Watts Cumulative power usage = 0.49 kWh Calculations: Electricity here in beautiful Seattle is $0.0886 per kWh. So, the cost of my test and adjusted to 24 hours is 4.2 Cents per day. Note, the national average for residential electricity is $0.1319 per kWh. At that rate, your cost might be closer to 6.5 Cents per day. That ain't much!