Electrical Power

Electrical PowerElectrical Power

The rate at which electrical energy is converted to another form of energy.

Thermal, Light, Motion…

Electrical PowerElectrical Power

Power = current x voltageP = I x VThe units for power: watts (W)

Electrical PowerElectrical Power

All appliances have a power rating to tell how much power it uses.

[http://www.nationalwholesaletools.com/index.asp?PageAction=VIEWPROD&ProdID=357]

[http://courses.knox.edu/envs101/appliances.JPG]

[http://www.thediyworld.co.uk/washer%20rating3.jpg]

Standard Voltage in the US is 120 V:

[http://www.northpower.com.au/wrs/res2.nsf/images/appliances/$file/Appliance2.jpg]

P = 240 W

P = 2.0 A x 120 V

Electrical EnergyElectrical Energy

The amount of power that is used over a given time.

Energy = Power x Time

Electrical EnergyElectrical Energy

Electric companies normally use the kilowatt-hour to charge for energy.

Remember: 1 kilowatt is 1000 watts!

MN is about 12 cents/kWh (When Taxes are Included)

[http://www.think-energy.net/_85256A170068279F_li_meter3a__file_meter3a.jpg]

= $82.56

x $0.12 per kWh688 kWh used

May 1st

May 31st

Electrical EnergyElectrical Energy

Example:How much does it cost to run

an XBOX 360 (160 W) for 3 hours a day for an entire month?

30 days x 3 hours = 90 hours

Electrical EnergyElectrical Energy

Energy = 160 W x 90 h Energy = 14400 Wh or 14.4 kWh Each kWh in MN is 11 cents so… 14.4 kWh x $0.11 = $1.58 per

monthClick Here for Xcel Energy Calculators

Average % of Energy Usage in a Home

[http://media.popularmechanics.com/images/tb_fllightbulb_sm.jpg]

[http://www.conservastore.com/productimages/03-0034B.jpg]

[http://www.gatech.edu/energybuzz/images/graphicBulbEfficiency.gif]