Cost in cents per 1000 lumens of
various lamps.
(Expressed in cents per kilowatt)
Cost Per Kilowatt Hour Of Electricity
Lamp Output 8¢ 10¢ 12¢ 16¢
100W
Incandescent 1,750 .46 .57 .68 .91
4’ Fluorescent
(CW-40W) 2,960 .11 .13 .16 .22
175W MH 14,000 .10 .12 .15 .20
400W MH 40,000 .08 .10 .12 .16
1000W MH 125,000 .06 .08 .10 .13
100W HPS 9,500 .08 .10 .13 .17
400W HPS 50,000 .06 .08 .10 .13
1000W HPS 140,000 .06 .07 .08 .11
Note about the chart: These figures denote the
part of a cent used to produce 1000 lumens. In
dollar terms the figures for a 1000W HPS are
$.0006, $.0007, $.0008, $.0011.
Step By Step
- The successful gardens I have
observed use a minimum of 1000
lumens per sq. ft during vegetative
growth and 1500 lumens during
flowering. These figures are bare
minimums, the more light the better.
Gardens with 1500-2500 lumens during
vegetative growth and 2000-3500
during flowering seem to do best.