Freezengirl and all, I could write a short book on this (LED vs Fluorescent (T5s-T8s) vs Halogen and HPS).
1st off - if you don't use them that often, or already have one or the other your setup is basically zero$ for the hardware. Your main concern is just power consumption. It will take quite a while (as in a few years) to make up for the up front hardware cost of good quality LED lighting.
I will just note here what I have done, what I am now doing, and the reasons for it.
Halogen and HPS type grow fixtures - Never used them and never would. The light spectrum and distribution is suitable for growing tomato plants or other larger type branching plants. Wattage is high (hundreds of watts) , residual heat btu is high. Setup requires special fixtures and ballasts, possibly light movers and cooling. All the plants I grow are seedings. Annuals, perennials and lots of lily seedlings. Not suitable for what I grow.
Fluorescent T5s - Never used them as my fixtures are all T8 electronic ballasts. The T5s have higher output lumens (wattage and heat are also higher) than the T8s and these are considered to be grow fixture type fluorescents. Cost is relatively high for the replacement bulbs, but the fixtures may be found for less $ now that LEDs are coming into favor.
T8 fluorescents - I used these for years and still think they are a good way to go 'on the cheap'. Replacement bulb cost is low, the fixtures will become harder to find as more LED fixtures become available. Heat generation is not that bad until you start using a larger number of these fixtures in a small indoor space. A few things to keep in mind though. Cheap fixtures use cheap less efficient ballasts. The power factor rating of the ballast determines the maximum lumens you can get from the bulbs. A normal power factor for a bulb, that will give you 2900 lumens from a 2900 lumen rated bulb, is 1.00. Cheap fixtures may have a power factors of 0.7 or lower (2030 lumens). My fixtures are all re-ballasted using 1.15 high output power factor ballasts ( 3330 lumens). Fluorescent lights are not very efficient for plant growth as the light spectrum is created by combining different phosphor coatings in the fluorescent tube. The spectrum is made up of very narrow spikes of red, green and blue. The plants really need a spectrum that is mostly in the deep red, and a lesser amount in the blue region of the spectrum.
T8-TLEDS - These are T8 LED tubes made to directly replace T8 fluorescents. Phillips Instant-fit are the lamps I have and am still using. Cost per replacement bulb is high at approx $23-$25 each. These are available in 3000k, 3500k, 4100k, 5000k color temperatures. The spectrum for the bulbs does not have the very narrow color spikes as the fluorescent bulbs do. I was able to pull spectrum values for the bulbs from Philips literature and plot them to show relative color spectrum values for these. Left most spectrum is blue, rightmost is far red. We are looking for only 6 to 8% blue spectrum to red. The 3000k (warm white) TLEDS would be the best choice of the four tubes that are offered.
LED fixtures - Now using along with the T8-TLEDs. See Philips Green Power Production Modules - distributed in the US by HortAmericas. Using the Gen1 deep red blue 34 watt modules. These are not suitable for growing full size 'your favorite taller branching plant here'. Designed for production growing of shorter plants on shelves. These don't appear to be that bright as they do not have the yellow/green portion in the spectrum that the human eye is most sensitive to. All the power and wattage is going into the areas of the spectrum the plants need for photosynthesis. The Gen2s which I do not have, cluster the LED emitters into groups. I have been told that the light distribution from these is the same as the Gen1s. Advantages - Proper spectrum for efficient plant growth, compact fixtures that fit well on plant shelves, easily adjustable over the plant canopy, low wattage, low heat. Nice compact healthy plants. Disadvantage - very high upfront cost. Not a good fit for taller bushy branching plants.
Power usage-
T8 fluorescents - 77 watts per fixture x 3 = 231 watts per shelf x 16 hrs per day
T8 TLEDs - 48 watts per fixture x 3 = 144 watts per shelf x 16 hours per day
LED - GPPM red/blue - 34 watts per fixture x 3 = 102 watts per shelf x 12 hours per day
The LED setup also has a great benefit in that the heat increase in the basement is greatly reduced.
<<=My homemade shelf hangers !!
Hope this helps !!
Hank Z
<<=My homemade shelf hangers !!
