Off-Grid Load Worksheet

 


Start by finding how many watts each appliance will consume. Do not add appliances that 
should be propane-fueled, such as cooktops, hot water heaters and electric heat. Then multiply rated wattage of each appliance by the number of hours per day, on average, that appliance runs. This gives the total watt-hours per day for each light or appliance. Do this for each and every appliance. The total for all appliance loads is the total watt-hours needed each day.

 

Figures below show some appliances commonly used in independent solar homes. Substitute your own daily hours for each and add other appliances not listed. Refrigerators come on and off on demand by thermostat, so running time per day is not known. A KILL-A-WATT meter will accurately test watt-hours used per day for any AC appliance up to 1875 watts.

 

Appliance

Watts

Run Time (Hr/Day)

WattHours/Day

Microwave oven

1260

1/4

315

Food processor

200

1/20

10

Toaster

1200

1/10

120

Coffee Maker

300

1

300

Clothes Washer

700

3/4

525

Vacuum Cleaner

550

1/4

138

Refrigerator/Freezer
(Energy Star)

 

 

1000

Small 4CF Apartment Fridge

 

 

945

12/24V NovaKool 4CF
(w/ added insulation)

 

 

300

10 CF Freezer, standard

 

 

1000

Window Air Conditioner

660

6

4000

Ceiling fan, AC

60

6

360

Ceiling fan, 12/24V DC

5-20

6

30-120

Well pump 120V AC
(100 gal/day)

1000

1/3

350

Well pump DC
(100 gal/day)

100

1

100

CF bulbs, equal to 15 watts

15

4

60

LED bulbs, equal to 5 watts

5

4

20

Computer

100

4

400

Laser printer, in operation

90

1/4

23

32” LCD TV

140

3

420

Satellite receiver

20

3

60

Stereo

40

4

160

 

 

 Use the tables below to determine the total energy in watt-hours per day used by all the AC and DC loads in your system.

 

1.      List all DC loads in the table below and calculate the total watt-hours per day.

 

Description of DC loads

Watts

X

Hours/day

=

Watt-hours/day

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Total DC watt-hours/day

 

 

 

2.     List all AC loads in the table below and calculate the total watt-hours per day.

Description of AC loads

Watts

X

Hours/day

=

Watt-hours/day

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Total ACwatt-hours/day

 

 

3.     Add DC & AC totals together to get TOTAL WATT-HOURS PER DAY.