LED lighting is starting to make its first inroads into the nursery garden sector. The luminaire designed by Fionia Lighting has demonstrated that the implementation of LEDs as supplemental lighting for plant growth is a viable route to large energy savings, not just through a 50 % reduction in electricity consumption, but also by way of surplus heat recovery. The excess heat generated is not arbitrarily radiated, but rather localised at the LED, where it can be collected and subsequently redistributed to where it can be used most efficiently.
Unlike HPS lamps, the intensity of LEDs can easily be adjusted simply by changing the input current. This opens up new possibilities that are simply not available with HPS lighting: regulation of plant growth and morphology through light quality, e.g. variation of the illumination spectra at different stages of growth, which also has the added advantage of reducing the use of growth regulatory chemicals; variation of light intensity for individual or groups of luminaires to compensate for differential shadowing of natural sunlight within the greenhouse area; and tailoring of the supplemental lighting to compensate for seasonal variations in the spectral composition of sunlight.
