How much will my electrical bill be?

1
How much will my electrical bill be?

• John Jones

2

• Electricity is priced and sold by the
  Kilowatt-hour. (kilo-1000)
• If you use 1000 watts of electricity for 1 hour,
  you use 1 kwh
• The price of a KwH of electricity is about 8
  cents (.08)

3
How does it add up?

• If you run ten 100 watt light bulbs for one hour
• 10 100 1000 watts
• 1000 watts 1 kwh
• 1.08 .08 (8 cents)

4
How much does it cost?

• Assume that you have three 300 watt bulbs on the
  outside of your house. You turn the lights on at
  900 p.m. and turn them off the next morning at
  7. How much does it cost to run the bulbs
  through the night?

5

• How long did the bulbs run? From 9 until 7 is 10
  hours
• How many total watts? 3300 900 watts
• Watthours 10 hrs 900 watts 9,000 watthours
• 9000/1000 9 kwh .08 .72

6
Try this one!

• A 5000 watt clothes dryer will dry a load of
  clothes in 1 hour. How much does it cost to dry
  the load of clothes?
• 5000 watts 1 hr. 5000 watthours
• 5000 watthours/1000 5 kilowatthours
• 5 kwh .08 .40 (40 cents)

7
If you can do this one, youve got it!!

• A football field has 36 bulbs rated at 500 watts.
  The coach turns on the lights at 500 p.m. and
  turns them off after the game at 1000 p.m.
• How much does it costs to run the lights during
  the game?

8

• 36 bulbs x 500 18000 watts
• Time 5 hours
• 18000590000 watthours
• 90000/1000 90 kwh
• 900 .08 7.20