DC and Sustainability in the Greenhouse

Direct Current B.V. is developing a DC version of the currently used HID ballast for the greenhouse market.

Last update on 20 September 2022
Greenhouse_2

DC and SON-T

The greenhouse market widely uses HID lighting fixtures to illuminate 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 significant amount of energy would be saved.

Currently used AC driver:
  • Input voltage 1ph 400Vac 50Hz
  • 1000W SON-T
  • Driver from Philips
  • Efficency: >96%
  • 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:
  • Input 700Vdc
  • 1000W SON-T
  • PCB mounted in a Philips case
  • Power Line communication
  • Efficency: >98%
  • 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

System Overview

The block diagram below clearly demonstrates 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 hand in hand.

Collaboration

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 learn the subject of DC.

Innovation

A new standard is also being developed for the DC infrastructure with the following starting points:

  • Less material
  • Higher system efficiency
  • Longer life span
  • Future-proof
  • Hybrid SON-T and LED lighting
  • Lower operating costs

Project Partners

The following companies are partners in making DC in horticulture possible:

  • DC Foundation Netherlands
  • Rabo Bank
  • Achmea
  • Productschap Tuinbouw
  • The Hague University
  • Joulz
  • Gavita
  • Agrolux
  • Stallingsbedrijf Glastuinbouw Nederland
  • Hellas Rectifiers B.V.
  • Direct Current BV