A focus here has been on driving LED's brightly, for the least input.
While it has been noted about 'fooling the eye' and that is quite likely completely correct, methods should be tried with actual plant growing to prove it out.
As such, i'll be doing a control and a test, of DC and whatever test circuit ends up being seemingly most efficient.
Over last winter, my system was DC, USB input into simple resistors and 17 LED's. White were also used, to see the plants for one thing, but also to check for leaf discolouration, blotchings, diseases and such.http://www.overunityresearch.com/index.php?topic=2780.0
Along those lines, initial experiments have been toward running simply and effectively from low voltages.
Likely, the end test system will be 5V again, it being a standard much like 12V, but also because it will form a direct comparison with known results from last year.
2 methods have been tried so far.
Both use a panel of 5x red, 5x blue and 5 x white LED's. Variable resistors are fitted that will balance output.
The first pic below is of a SWES wireless electricity setup, where the output lights the 15 via a ferrite inductor as pick up. 1.35V, 50mA.
The second pic is of a blocking oscillator, 0.02uF '203' ceramic cap and 3K tank, 120/120 windings on ferrite, 3V CR2032 coin cell at 12mA.
Both need work, both are infancy ideas. The wireless method appeals, to be able to swap out, alter or replace whole sections of lights on a larger system, without any wiring being needed. It's also my own IP, so no problems with copyrighted methods, Patents and such.