A Red LED Light to Turn Greenhouses Greener...and More Effective

Live in Northern Europe and eat tomatoes, peppers, chilies in winter? Chances are sky-high your nightshades were grown in one of the vast landscape of greenhouses covering the low-lying Netherlands. These greenhouses are big energy hogs, and the Dutch toil to cut both energy use and emissions from these food factories. Now Japanese chemical and consumer goods company Showa Denko claims to have come up with a red LED that is "optimized to accelerate plant photosynthesis" (fancy speak for making the plants grow faster, at the same time that it can cut energy use by up to 70 percent - compared to 'regular' or current use red LED lights. How do they do it?
Showa Denko's red LEDs are aluminum-gallium-indium-phosphide (AlGaInP) LED chips, and the company has been improving their performance over the last two years by what the company said is "developing" a new light-emitting layer in the LED. The very high output of these chips makes them perfect for greenhouses, Showa Denko said, and the company has begun to sell samples for light developers to play with.

LEDs popular in the plant greenhouse
Transplanted Canadian Sylvain Dubé has spent 13 years in Sweden studying the effects of light on plants. He's come up with lots of ideas for how to make greenhouse plants happy - the basic principal is the more the light approximates sunlight, the happier the plants are. "Blue" light in the morning gets the plants to open up and take in necessary CO2. Daylight lamps trigger photosynthesis, as do red lights.

Price is the crux of the issue
There's no doubt that LEDs bring down the energy consumption of greenhouses - but the lamps themselves run two to three times more expensive than the type of sodium lamps or fluorescent lamps most commonly used at present. Dubé's company Heliospectra aims for greenhouses to cut energy costs by at least half using his special HB-LED system, which combines different colored LED lights with a control system. He expects to have a pilot project in the Swedish town of Borås this year. Dutch early adopters of current red LED lights have found payback time to the systems is about 3 years.

Showa Denko's chips, on the other hand emit red light with a 660 nm wavelength, and the company claims to have achieved the highest output for these 660 nm LED chips. Showa Denko says that use of its chips in red LED light systems for greenhouses would cut energy use an additional 70 percent from red LED systems already in use in 30 greenhouses in Japan.

And the benefit for consumers? Probably not a cost differential. However, Dubé has shown that herbs grown with his combination of Heliospectra LEDs have both more taste and more aroma. Via NyTeknik and here
Note: Photos via Showa Denko.
Read more on greenhouses
Greenhouse Farming in Spain Provides Potent Local Relief from Climate Change
Dutch Flower Growers Get Greener
Recycled Bottle Greenhouse: Build Your Own
News From the Future Dept: Greenhouses Burning Coal

Tags: Farming | Food Miles | Lighting | Local Food

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