First find your average daily kWh usage in the left column then select the system
size needed to reduce your usage by 25%, 50%, 75% or 100%. The system sizes
shown in the table are in kW (kilowatts) A kilowatt (kW) is equal to 1000 watts. 
Add a "0" on to the System. Size in kW to determine the out-put in watts and
drop the decimal point.
Your Average Daily
System Size in kW (add a "0" to convert to watts)
kWh usage
 25% 50% 75% 100%
8 to 10
 0.45 0.91 1.36 1.82
11 to 13
 0.59 1.18 1.77 2.36
14 to 16
 0.73 1.45 2.18 2.91
17 to 19
 0.86 1.73 2.59 3.45
20 to 22
 1.00 2.00 3.00 4.00
23 to 25
 1.14 2.27 3.41 4.55
26 to 28
1.27 2.55 3.82 5.09
29 to 31
 1.41 2.82 4.23 5.64
32 to 34
 1.55 3.09 4.64 6.18
35 to 37
 1.68 3.36 5.05 6.73
38 to 40
 1.82 3.64 5.45 7.27
41 to 43
 1.95 3.91 5.86 7.82
44 to 46
 2.09 4.18 6.27 8.36
47 to 49
 2.23 4.45 6.68 8.91
50 to 52
 2.36 4.73 7.09 9.45
53 to 55
 2.50 5.00 7.50 10.00
56 to 58
 2.64 5.27 7.91 10.55
59 to 61
 2.77 5.55 8.32 11.09
62 to 64
 2.91 5.82 8.73 11.64
65 to 67
 3.05 6.09 9.14 12.18
68 to 70
 3.18 6.36 9.55 12.73
71 to 73
 3.32 6.64 9.95 13.27
74 to 76
 3.45 6.91 10.36 13.82
77 to 79
 3.59 7.18 10.77 14.36
80 to 82
 3.73 7.45 11.18 14.91
83 to 85
 3.86 7.73 11.59 15.45