DC and Sustainability in the Greenhouse
Project start/finish: 2009-2011
The greenhouse market is widely using HID lighting fixtures to illuminate the crops. When using supplemental lighting based on AC, a lot of energy is wasted in the conversion of AC into DC in each lighting fixture. This energy loss is converted into heat waste in each fixture. If the entire greenhouse would use DC, these losses would be reduced. By centralizing conversion of AC to DC in the greenhouse, instead of local conversion in each of the lighting fixtures, a lot of energy would be saved.
DC and SON-T
Block diagram of the HID lamp connected directly to DC:
Currently used AC driver:
Input voltage 1ph 400Vac 50Hz
Driver from Philips
Power factor: 0.98
Input current: 2,6 Aac
Wire 3x 2.5 mm² + PE max. 9 lamps
Wire 3x 4 mm² + PE max. 15 lamps
Prototype DC driver:
PCB mounted in a Philips case
Power Line communication
power factor: NA
INput current: 1,4 Adc
Wire 2x 2.5 mm² + PE max. 11 lamps
Wire 2x 4 mm² + PE max. 18 lamps
The block diagram below makes clear that central distribution panels belong to the past and are to be replaced by a local connection to a DC bus where communication and energy go together.
Direct Current B.V. also sponsors this project Gelijkspanning Komt in de Kas (DC in the Greenhouse). Direct Current B.V. gives technical support for the development of the DC infrastructure and the development of DC lighting fixtures in the greenhouse.
The following organizations displayed in the image on the right side are also sponsors of this project. For more information, please visit the website of DC Foundation at www.dcfoundation.org. In the Hague College, we have initiated a program in cooperation with the DC Foundation in order to motivate students to work with DC and to teach the subject of DC.
Direct Current B.V. is developing for the greenhouse market a DC version of the currently used HID ballast.
In addition, a new standard is being developed for the DC infrastructure with the following starting points:
- Less material
- Higher system efficiency
- Longer life span
- Hybrid SON-T and LED lighting
- Lower operating costs
The following companies are partners in making DC in horticulture possible:
- DC Foundation Netherlands
- Rabo Bank
- Productschap Tuinbouw
- The Hague University
- Stallingsbedrijf Glastuinbouw Nederland
- Hellas Rectifiers B.V.
- Direct Current BV
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