POWER MEASUREMENTS (APPROX) DeviceIdle/Steady WPeak W Clippers7.5 W LED/Laser Light2.5 W Cell Phone Charger.5 W4.5 W Incandescent Bulb25 W Fluorescent Bulb13 W Halogen Driveway Light.5 W245 W Handheld Game (1 vs 2 scr.) 2 W2.5 W Macbook20 W50 W LCD Monitor.6 W40 W Desktop Computer90 W220 W
POWER MEASUREMENTS (APPROX) DeviceIdle/Steady WPeak W RAM (1 stick)up to 5 W Hard Disk (SATA)7-10 W Hard Disk (SSD).5 W2.5 W Video Card (low-end)25 W50+ W CPU30 W100+ W
WATT HOURS Simple measure: 1 watt hour is 1 watt of energy consumed for one hour 1000 watts = 1 kilowatt (1kW) 1 kilowatt hour is 1000 watts consumed for one hour If we leave our test computer idle for one hour, that is equivalent to.220 kWh (or 220 watt hours) Would need to leave computer on for slightly longer than 4.5 hours to consume 1 kWh
HOUSEHOLD POWER CONSUMPTION “Average” household power consumption?
HOUSEHOLD POWER CONSUMPTION “Average” household power consumption? It depends…
HOUSEHOLD POWER CONSUMPTION “Average” household power consumption? 2010: 11,496 kWh per annum TN: 16,716 kWh/yr VT: 6,912 kWh/yr ME: 6,252 kWh/yr …why? Source: US Energy Information Administration
POWER GENERATION Approximately 5,800 operational power plants >= 1MW capacity in US. Source: US Energy Information Administration
POWER GENERATION Source: US Energy Information Administration
CO 2 GENERATED BY VARIOUS FUELS Fuel TypeLbs CO 2 / kWh Coal2.02 – 2.12 Natural Gas1.12 Oil1.57 – 1.70 Source: US Energy Information Administration Assuming avg. heat rate for steam-electric generation
WHERE DOES OUR POWER COME FROM? Total Generation Capacity (VT): 582,000 MWh Sources: Nuclear (436,000 MWh) Hydroelectric (100,000 MWh) Other Renewables (45,000 MWh) So we’re good, right? Source: US Energy Information Administration
ELECTRICITY RATES Relevant as well is the rate charged per kWh of electricity. VT (Green Mountain Power) rate is approx $0.16/kWh (residential – commercial and industrial rates are lower) -Utilities often charge different prices for peak vs off- peak usage (why?)
POWER COSTS (APPROX) DeviceIdle/Steady WPeak WIdle Cost/mo Clippers 7.5 W $0.86 LED/Laser Light 2.5 W $0.28 Cell Phone Charger.5 W4.5 W$0.06 Incandescent Bulb 25 W $2.88 Fluorescent Bulb 13 W $1.50 Halogen Driveway Light.5 W245 W$0.06 Handheld Game (1 vs 2 scr.) 2 W2.5 W$0.23 Macbook 20 W50 W$2.30 LCD Monitor.6 W40 W$0.07 Desktop Computer 90 W220 W$10.37
SCALE OUT IDLE POWER USAGE Cell Phones: ~331.6M subscribers (2011) [CTIA] … x 360 watt hours/mo (this is extreme…) Desktop Computers: ~2B by 2014 [Gartner] Other devices (cable modem - ~5W; cable tv receiver ~40W)
DATA CENTERS Keep this information in mind for later discussion on personal computer power usage… From here, we shall move on to data center power usage. Readings: -Koomey -Belady (PUE) -Belady (WUE)