I have experience growing with hydroponics and an LED setup. It helps keep things cool, and the power consumption, science tells us, is much lower. You'll want approximately 90% red energy and 10% blue energy, but you'll want to spread them out if possible, rather than having separate red and blue lights.
The problems are that the LED light is extremely directional and also loses a lot of it's power over distance. This means you need a lot of LEDs and you need to put them close to the leaves. That means from my experience it doesn't work well if you just hang them over the plants because then it only experience light coming straight down which gets blocked if there are multiple layers of leaves.. Whereas the sun and incandescent bulbs gives more ambient light and more light reaches the lower leaves. This creates logistical problems, because it may not work well if you just hang your lights over your plants, it's good to have some light coming in from the side. But each plant has different contours and shape. That means you might not be able to put your plants as close together, and you are dedicating several 13 watt bulbs to a single good sized plant. If your crafty then you can figure out how to do this, but the equipment I have used makes this seem wasteful.
I've been successful with what are referred to on ebay as "bud spotlights". The first shipment I got from one person was great.. very powerful, but extremely directional even for LED lights.. My next shipment I got more lights even though the old ones were no longer available and it was a different seller, and these turned out to spread the light out more. They both work well, but I've had about a 30% failure rate on the second shipment and I'm not sure if the person who sold them to me is going to replace the failed ones or not, they said they may, we'll see, but according to the auction rules I don't think they have to. They are also continuing to fail on me, so I may have only a few or none left eventually
But again, the first shipment they are all 100% working, and it is the electronics, NOT the LEDs which are a problem in the second shipment.
These are what I got in the second shipment, and both sellers of bud spotlights that i can find on ebay right now are selling these same ones, so I wouldn't recommend them, but if you can find something like it for the same price you might try a few and experiment and see how they work out.
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Ok, here's the part where I give the disclaimer that I have tried to figure out the costs vs. benefits of these things and I just can't quite see the savings that SHOULD be coming with these, and I think it has to do with the lights being extremely directional. And the other problem is that too many people have come out with these things without really seeing if their product provided optimal coverage. The panels, which I've also tried spread the lights out too far, so they are a bit weak.. there are some other panels out there right now that don't spread them out as far, but they are rather expensive to test out.
http://cgi.ebay.com/High-Power-55-W...39:1|66:2|65:12|240:1318&_trksid=p3286.c0.m14
vs.
http://cgi.ebay.com/225-LED-GROW-LI...39:1|66:2|65:12|240:1318&_trksid=p3286.c0.m14
And the spotlights I'm using now, the led's are practically touching each other, so I think that is just too dense.
Since LEDs take no power to "cool down" I would say LEDs can potentially work better with a traditional gardening setup, and especially for gardening small plants or if heat is an issue. With more work on logistical issues, LEDs may be able to beat incandescent and cfl hands down.
On the other hand it may be difficult to beat this beast, which takes full advantage of an incandescent bulb:
So we need a system that takes full advantage of the directionality of the LED bulb. I mean, can you imagine growing something like corn with LEDs? Seems like a logistical nightmare, but I'm hopeful.
