The plants need some form of artificial lightning to thrive in Norway in the winter.
After consulting Windowfarms.org, we decided to try with some 8W E27 socket led bulbs. The light output measured in lumens is about the same on a 10 watt led bulb as a 20 watt CFL.
| Light Output | LEDs | CFLs | Incandescents |
|---|---|---|---|
|
Lumens
|
Watts
|
Watts
|
Watts
|
|
450
|
4 – 5
|
8 – 12
|
40
|
|
300 – 900
|
6 – 8
|
13 – 18
|
60
|
|
1100 – 1300
|
9 – 13
|
18 – 22
|
75 – 100
|
|
1600 – 1800
|
16 – 20
|
23 – 30
|
100
|
|
2600 – 2800
|
25 – 28
|
30 – 55
|
150
|
This table is from eartheasy.com
The light was on for about 18 hours each day (on one plant). Until I suddenly regretted buying a cheap bulb from china (THIS ONE).
One morning it started smelling really bad, the light started flickering, and smoke started coming out from the bulb:/
After this incident, clearly caused by the extremely badly designed power supply, I started using some daylight CFL bulbs. Compared to led bulbs; they use more energy, gets hot, and is not that directional. But they are safer..
Check out this site for more interesting lightning discussions.
