I actually looked into artificial lights, but unless you have plenty of
bulbs at different heights, you will run into something growing higher
than others. With the sun, the difference between 1 foot or 2 (e.g.,
taller leaves or spikes) is not significant because the sun is so far
away; but with artifical light, that's a very big difference. I bought a
foot-candle meter so as to measure the foot-candle of the light for my
orchids. When 6 inches below the light is 900 foot-candle, 1 foot below
the light becomes way too dim.

Your best solution is actually using the western sun with either
miniblinds or get some lace fabric from wal-mart. I have southwestern
windows that I use for all my orchids. Where there is no miniblind, I
hang a piece of lace fabric which breaks down the sun light. With phals,
I just place the plants further away from the window. That way, my
catleya and frag get their strong doses while my phals get reduced
light. With miniblinds, I usually adjust it to get full sun in late
afternoon so it will get broken sunlight when the sun is higher up and
still very strong. With lace you don't have that problem because the
light is already broken up.

sandra wrote:

Hello, I've been recently growing a few orchids(mostly phals) in my
west window, but lately their leaves have been turning dark, dark
green, the roots all still look fine, I'm just worried about the
lighting.
Anyway, I'm thinking about doing artificial lighting next week, and I'm
wondering if 2 40 watt daylight bulbs in a shop light fixture will be
okay?
I'm just wondering if this will be enough, I can suppliment this with a
few hours of shaded sun that my west window gets.
Thanks, Sandra