Sunlight:
  

You may have read that the plants do not like direct sunlight. This is true, but not to the extent that the plant is a shade lover, - as some would suggest. In fact, in my experience, the plant likes as much light as it can possibly get without getting too much direct midday sunlight. 

Venetian blinds on a south facing window will protect them from excess, otherwise ideal is if you have a window that gets just a little morning or evening sun. Ensuring enough light will encourage growth and the production of rich dark green leaves.

 

Artificial Light:  

I’m having success growing under artificial light. In order to get more winter growth, and because of a general lack of suitable window space, I set up some plants in a windowless utility room. These have lights on a timer-switch (16hrs on, 8hrs off) and are growing well.

I’ve heard of and seen fluorescent strip lighting being used by other people, but I’ve simply used ‘energy-saver’ bulbs in standard light fittings. These are in effect mini fluorescent lights anyway.

The plants (mostly youngsters in 10cm pots) are between 25cm to 100cm away from the light sources. I originally suspended a total of four lights above the plants, kind of one at each end of two parallel ‘shelves’ of plants.  This worked okay but since then I've added an extra light above the middle of the lower shelf, so that this shelf has three lights, and I have extended, as can be seen in the photograph below, with more plants (and another light) included in an area at the back of the shot (in front of a mirror)  

plants under artificial lights (energy-saver bulbs) The ‘shelves’ consist of just over a dozen or so plants on each shelf, - each shelf about 1.5m in length, 0.4m wide.

As you can see, one set of plants is slightly further away (lower down) from the light sources, so there is quite a range of distances from plant to light, but all plants are growing well and it's been so successful that I've extended into other cupboards.

The total light bulb wattage was originally 96 watts, consisting of 2 x 25 watts (1200 lumen each) plus 2 x 23 watts (I assume proportionally less lumens for the lower wattage), with later another 18 watts added above the middle of the lower shelf, and a further 25 watts for the inclusion of more plants (in front of the mirror at the back). - Quite bright over all, each bulb >= 100w ordinary bulb equivalent (an ordinary 60w bulb outputs ~700 lumen), but without producing too much scorching heat (or using too much power).  Of course, you wouldn't need this many lights for fewer plants.  

Considering that there is no need to mimic direct sunlight, I would argue that expensive high power lamps are not necessary.  However, you do want to get a bright crisp light.  Note that some energy-saver bulbs advertise themselves as producing an especially 'warm', 'soft' or yellow light.  These are to be avoided if possible. 

Like I say, I don't believe specialist high power lighting is absolutely necessary, but one of my plant recipients has been experimenting [...]

Note that another way to use artificial light would be by a window, i.e. to supplement natural winter light rather than completely replace it.

 

24hr Artificial Light

I tried this as an experiment with a few plants at the beginning of January 2002.  Apparently it can work with some plant species to increase growth rates.  I stopped after 8 weeks.  I wanted to re-arrange my set-up and this included reclaiming the cupboard space that was being used.  During the 8 weeks the plants did grow, but did not appear to be growing any faster than those under the 16hr on 8hr off set-up.  I have to say the the 16hr on / 8hr off plants did look healthier too.  If anyone else has done a similar experiment I'd be interested to hear about it, particularly if they've done it for longer than a couple of months.