It emits a deep-red light at a wavelength of 660 nanometers, which is perfect for plant photosynthesis. With an efficiency of 37 percent — one of the highest for a light source of this color — it also yields considerable energy savings compared to conventional lamps. In a pilot project in Denmark, which used around 50,000 LEDs to illuminate a cultivation area of several thousand square meters, power consumption in the greenhouse fell by 40 percent.
Relatively little of the light used by plants for their growth is from the visible light spectrum. Chlorophyll molecules mostly absorb deep-red and blue light for the purposes of photosynthesis. Osram Opto Semiconductors has therefore developed an extremely efficient red LED with an emission curve that is very closely matched to the spectral sensitivity of chlorophyll. The new LED is based on the thin-film technology used for high power semiconductor chips.
In greenhouse cultivation, some plants are grown on several levels stacked on top of one another. For this reason, the new LED is available in two variants, each with a different beam angle. The Golden Dragon Plus has a beam angle of 170 degrees and is therefore well suited for use in reflector lamps for illuminating large areas under cultivation. By contrast, the Oslon SSL LED, with a beam angle of 80 degrees, is designed for use in multi-level applications, such as those for the cultivation of lettuce. Using LED light, it is also possible to promote different growth phases of the plant under cultivation. Red light, for example, encourages plants to grow in length, whereas blue light fosters bud formation, for example. Controlled variation of the proportion of blue light between ten and 30 percent reduces use of fertilizer and other chemicals.
Compared to conventional high-pressure sodium lamps, the luminous efficacy of the system as a whole is 60 percent higher with red and blue LEDs. And with a service life of 100,000 hours, the LEDs provide maintenance-free operation for many years. Also involved in the pilot project with Osram were Arrow Electronics and Fiona Lighting A/S, a Danish company specializing in LED lighting for commercial horticulture. Highly efficient LED lighting forms part of the Siemens environmental portfolio, which generated around €28 billion in sales for the company in fiscal year 2010.
Dr. Norbert Aschenbrenner | Siemens InnovationNews
Scientists create biodegradable, paper-based biobatteries
08.08.2018 | Binghamton University
Ricocheting radio waves monitor the tiniest movements in a room
07.08.2018 | Duke University
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.
Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
14.08.2018 | Life Sciences
14.08.2018 | Life Sciences
14.08.2018 | Earth Sciences