Ahh, laptops. What would we do without them? I would like to point out the Apple 20w (20 inch widescreen) is an iMac. The iMac is a computer with the monitor and main system in the same unit, so its hard to separate (though doable) to separate those numbers. It is also a more powerful system than the laptops I tested, but the iMac is a desktop computer, so that too is expected.
      On                   Power Off        
      Backlight Full or for desktop Backlight at lowest Backlight off   Screen Off   Averages         Estmated power Estmated power
User Maker Screen Size Processer Low Processor High Processer Low Processor High Processer Low Processor High Processer Low Processor High Processer Low Processor High Standby Hibernate Shutdown usage per year cost per year
Travis Apple 15w 28 41 21 36 21 35 18 33 22.00W 36.25W 2 1 132.23 KWH $10.92
Adrien HP 25 29 17 23   14 21 18.67W 24.33W 0 0 0 109.34 KWH $9.03
Jennifer Vaio 27 38 19 28   15 24.00W 33.00W 1 0.5 0.5 142.15 KWH $11.74
Travis Apple 20w 73 85 50 62   36 48 53.00W 65.00W 2 1 313.14 KWH $25.86
Averages     38.25W 48.25W 26.75W 37.25W 21.00W 35.00W 20.75W 34.00W 28.00W 39.92W 1.25W 0.25W 0.63W 174.22 KWH $14.38
Kilowatts per hour   0.04 KWH 0.05 KWH 0.03 KWH 0.04 KWH 0.02 KWH 0.04 KWH 0.02 KWH 0.03 KWH 0.03 KWH 0.04 KWH 0.00 KWH 0.00 KWH 0.00 KWH
Cost per hour   $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
Kilowatts per day   0.92 KWH 1.16 KWH 0.64 KWH 0.89 KWH 0.50 KWH 0.84 KWH 0.50 KWH 0.82 KWH 0.67 KWH 0.96 KWH 0.03 KWH 0.01 KWH 0.02 KWH
Cost per day   $0.08 $0.10 $0.05 $0.07 $0.04 $0.07 $0.04 $0.07 $0.06 $0.08 $0.00 $0.00 $0.00
Kilowatts per month   27.92 KWH 35.22 KWH 19.53 KWH 27.19 KWH 15.33 KWH 25.55 KWH 15.15 KWH 24.82 KWH 20.44 KWH 29.14 KWH 0.91 KWH 0.18 KWH 0.46 KWH
Cost per month   $2.31 $2.91 $1.61 $2.25 $1.27 $2.11 $1.25 $2.05 $1.69 $2.41 $0.08 $0.02 $0.04
Kilowatts per year   335.07 KWH 422.67 KWH 234.33 KWH 326.31 KWH 183.96 KWH 306.60 KWH 181.77 KWH 297.84 KWH 245.28 KWH 349.67 KWH 10.95 KWH 2.19 KWH 5.48 KWH
Cost per year   $27.67 $34.90 $19.35 $26.94 $15.19 $25.32 $15.01 $24.59 $20.25 $28.87 $0.90 $0.18 $0.45