Electricity Cost Problems- Formulas

Example Questions Electricity Costs 14.7 cents/kWh. If my total bill is $38.22, how many kWh were used? G Rate = 14.7 cents/kWh Cost = $38.22 R E = ? A Cost = E * Rate S $38.22 = E * $0.147/kWh S E = $38.22/$0.147/kWh E = 260 kWh

Example Questions Electricity Costs 11.4 cents/kWh. If my total bill is $27.35, how many kWh were used? G Rate = 11.4 cents/kWh Cost = $27.35 R E = ? A Cost = E * Rate S $27.35 = E * $0.114/kWh S E = $27.35/$0.114/kWh E = kWh

Example Questions Mr. Reitzel replaced six 60 W incandescent bulbs in his house With six 13 W compact fluorescent bulbs. If the bulbs are on for an average of 3 hours a day. How many kWh will he save? If electricity averages 11.4 cents/kWh, how much money will he save? G Bulb 1 = 60 W Bulb 2 = 13 W 6 bulbs 3h/day R kWh saved Money saved A and S Difference = 60 W – 13 W = 47 W Power Saved = 47 W * 6 bulbs = 282 W Hours On = 3*365 = 1095h A and the s’s E = 282 W * 1095 h = Wh = kWh Savings = kWh*$0.114/kWh =$35.09 R kWh saved Money saved

Energy Guide Includes Average Energy use per year or month How it compares to other brands/models

Energy Star Energy Star: one of the most efficient appliances in it’s class

Classic Meter vs Smart Meter Must be physically read to determine use Can only provide total electricity use Information transferred electronically Provides hourly usage data Allows for Time Of Use (TOU) billing. (charge more $ during peak times)

Where can we make some big changes?