DE Cost is actually comparable If not cheaper that a top of the line single ended setup . I have heard lots of good results but am doing my first run with them now. You can get the nanolux de with ballast bulb and hood for around 400 bucks
Just found this in the most recent Maximum Yield Indoor Gardening mag.
There was a study published in June 2014 by plant scientists at the University of Utah
entitled "Economic Analysis of greenhouse lighting; Light Emitting Diodes vs. High intensity
Discharge Fixtures" compared the most efficient HPS and conventional LED fixtures head-to-head to determine the lowest cost per-micromole of photo synthetically Active radiation (PAR) photons per year in several different greenhouse applications.
A micromole or pmole is simply a term describing a quantity of photons.
Anyone spending thousands of dollars to equip should check out the Utah study. It found
the best 1000-W, double ended HPS lights and the best conventional LED fixtures available at the time could produce photons in the photosynthetic range with equal electrical efficiency,
producing between 1.66 and 1.7 pmoles of PAR photons per joule.
Both light fixtures far outperformed the mogul based single ended HPS fixtures, which have efficiencies of only 1.2 pmoles per joule.
If electricity was the only consideration for growers, mogul based HPS fixtures could
be replaced with either the best double ended HPS or the best LED fixtures, and you can
call it a day. Either of these replacements would consume half the electricity of older HPS
fixtures, and both are equally effective and would cost far less to own and operate over
a 5 year period. However there are many factors in choosing between HPS or LEDs for supplemental or primary indoor garden lighting, such as bulb replacements, HVAC costs,
spectrum choice and the initial capitol cost.
The Utah study weighed all of these and found
that the only situation in which LED was less costly then the equally efficient double ended
HPS over a 5 year period was when it was used in smaller greenhouses/rooms with wide
isles requiring highly directional light. In all other situations double ended HPS fixtures were more economical because of their lower initial capitol cost. That was then.
Shortly after the Utah study was published, a new LED technology emerged in agricultural
lighting-- the remote phosphor uses high energy LED lights to excite a phosphorescent
coating. The coating then emits light at various color frequencies.
Remote phosphor LED agricultural light promise a higher fixture efficiency of up to
2.4 pmoles per joule.
