Every renewable energy project has to start with analyzing your current energy consumption. For instance in a residential project you will want to start with doing an energy audit, recording the energy consumption of each appliance in your home.

This will help you to determine your energy loads and maybe even pinpoint a few appliances that could be replaced with a unit that is more efficient.

Use this formula to estimate an appliance's energy use:

**(Wattage × Hours Used Per Day) ÷ 1000 = Daily Kilowatt-hour (kWh) consumption**

1 kilowatt (kW) = 1,000 Watts

Multiply this by the number of days you use the appliance during the year for the annual consumption in kWh per year.

*If you cannot find the wattage of your specific appliance you can estimate the current draw in amperes (amps) by either seeing if the amps are marked on the unit instead of the watts. You can then multiply the amps times the volts (most small appliances are 120v) to determine the watts.*

#### Estimating the Annual Energy Cost

Multiply the annual consumption in kWh per year (that you calculated above) by your local utility's rate per kWh consumed to calculate the annual cost to run an appliance.

Note: To estimate the number of hours that a refrigerator actually operates at its maximum wattage, divide the total time the refrigerator is plugged in by three. Refrigerators, although turned "on" all the time, actually cycle on and off as needed to maintain interior temperatures.**Examples:**

** Window fan:**

(200 Watts × 4 hours/day × 120 days/year) ÷ 1000

= 96 kWh × 11 cents/kWh

= $10.56/year

** Personal Computer and Monitor:**

[(120 Watts + 150 Watts) × 4 hours/day × 365 days/year] ÷ 1000

= 394 kWh × 11 cents/kWh

= $43.34/year

This chart shows how much energy a typical appliance uses per year and its corresponding cost based on national averages. For example, a refrigerator/freezer uses almost five times the electricity the average television uses.* Courtesy of Energy.gov*

Following are some examples of wattages for various household appliances:

Aquarium = 50–1210 Watts

Clock radio = 10

Coffee maker = 900–1200

Clothes washer = 350–500

Clothes dryer = 1800–5000

Dishwasher = 1200–2400 (using the drying feature greatly increases energy consumption)

Dehumidifier = 785

Electric blanket (Single/Double) = 60 / 100

Fans

Ceiling = 65–175

Window = 55–250

Furnace = 750

Whole house = 240–750

Hair dryer = 1200–1875

Heater (portable) = 750–1500

Clothes iron = 1000–1800

Microwave oven = 750–1100

Personal computer

CPU - awake / asleep = 120 / 30 or less

Monitor - awake / asleep = 150 / 30 or less

Laptop = 50

Radio (stereo) = 70–400

Refrigerator (frost-free, 16 cubic feet) = 725

Televisions (color)

19" = 65–110

27" = 113

36" = 133

53" - 61" Projection = 170

Flat screen = 120

Toaster = 800–1400

Toaster oven = 1225

VCR/DVD = 17–21 / 20–25

Vacuum cleaner = 1000–1440

Water heater (40 gallon) = 4500–5500

Water pump (deep well) = 250–1100

Water bed (with heater, no cover) = 120–380