Most efficient grow lights? LEDs?

[littlejohn]

Since thiers so many experts here on lights and lighting I was hoping you could answer a few questions on growing food with lights. And yes I'm talking about food not herbs for prohit so money does matter

a) Can a large battery of LED lights put out enough lumens/light to grow crops?
b) Do LEDs put out the right type/wavelength of light for crop growth?
c) Has anyone done any experimentation on useign LEDs for growing plants?

Obviously if thier is anything on the net about the subject of efficient lighting for plants I'd like to know about it. Also if LEDs dont work well whats the best alternative? I've heard flourecent lights only work well for a short period of time before degradeing so I'm not sure their that great of an alternative for long term use.

[BatteryCharger]

LEDs will work but not very well. They are less efficient than fluorescents and HID lights. Metal halide and high pressure sodium are the most efficient types of light you can buy, and also produce the best spectrum(s) for growing. Which type you use depends on what you are growing.

[The_LED_Museum]

Generally speaking, plants require wavelength peaks of 470nm and 630nm for feeding the organism and for flowering, respectively.
This can vary somewhat depending on the type of plant you are attempting to grow, but these are generally accepted as the two wavelength peaks.

[jkuo13]

There's another thread about this in the LED forum:

http://candlepowerforums.com/vb/showthread.php?t=101891


LEDs should work fine as growlights. You can even buy led growlights, although the price for larger clusters is probably far more expensive than an equivalent HID growlight setup.

Just a few random links that I've found reading the forums or just surfing:

http://www.ledtronics.com/ds/plantled/
http://www.growwithleds.com/ledproducts.htm
http://ledgrowlights.com/Growlights.htm
http://www.gotoreviews.com/archives/...r-growing.html
http://www.gotoreviews.com/archives/...w-lettuce.html

Personally, I think LEDs should work great for leafy type plants and ornamental flowering plants. I'm not entirely convinced LED growlights are the best choice for heavy fruiting plants though. It's been a long time since I took bio (and slept through the botany lectures...), but I do vaguely remember other wavelengths (besides the typical blue and red needed for chlorophyll) that were used by caretenoid, etc. pigments. It seems to me that having parts of the spectrum missing as with the current generation of LED growlights would result in suboptimal results with plants that utilize other photosynthetic pigments.