My ultimate goal with this high-powered LED panel is to mimic the intensity and spectra of the solar light in the region of photosysnthetic active region (PAR 400-700 nm). This project is the first step to control light intensity by a bank of LED light with a defined pattern. The intensity of LED is sufficient to match and exceed the solar intensity (max around 2400 µE/m2-s).
To mimic the solar spectra as the photo below is not that simple as with the intensity. Each type of light source has its own advantages and disadvatages. Incadescent bulb produces continuum spectra but it also generates a lot of heat as well. The coolwhite LED is another promissing source, but it produces a bit more purple light and is difficent in the region of 490nm. I were working to add royal-blue LED to add to the hump. In the meantime, the cool-white LED seems to satisfy the microalgae. With a rapid development of LED and mixing of phosphor layer on top of the LED chip, having a solar speactra by the LED light seems not too far.
On the second photo, you will see the high-powered LED on the job. This is a pilot reactor using LED. Other reactors are using T-5 flourescent bulbs. Together with a heat-exchange, we always feel cozy in the lab.