Koper besparen

Technical theme 2: copper conservation

 

Innolumis LED lighting requires less power than conventional lighting. The diameter of an electricity wire determines the maximum allowable power flow. It is therefore possible to use thinner electricity wires with Innolumis light fixtures. Especially in new neighbourhoods this leads to a large cost reduction, and moreover less use of copper and a lower CO2 footprint. These are some of the positive side effects of low-energy lighting.

 

Conventional specifications

A project recently awarded to Innolumis contained the specification that every fixture should be fed by a 3 x 1.5 mm2 QWPK cable. This diameter had already been prescribed for many years and was based on conventional lighting. The maximum current through this cable is 22 A – that is high for the energy-efficient Innolumis LED lighting, which requires about 65% less electricity than the conventional SON that needed to be replaced.

 

Thinner cable

The project involved more than 500 Innolumis Nicole luminaires with a capacity of 24 W. These fixtures have a power consumption of 28 W, requiring a current of 0.112 A. Innolumis took the initiative to investigate a thinner cable than was specified, namely a 3 x 1 mm2 QWPK cable. This cable still has a maximum current of 14 A.

 

Customer and contractor convinced

A thinner cable has a relatively higher resistance, which means more heat development. This effect, however, turned out to be negligible: for the project of 544 luminaires this resulted in 4 kWh per year. So there was no technical or energy-related obstacle against using a 1 mm2 cable in the mast. In addition to direct financial advantage, a thinner cable reduces the CO2 footprint. The customer and the contractor were convinced and now use a thinner cable.

 

The key facts and the environmental gain of the project:

  • 544 masts
  • Replacement of SON-T 90 watt with Innolumis Moonlight 24 watt
  • 4,146 m of cable
  • Copper conservation: 109 kg
  • Insulation material conservation: 47 kg
  • Higher energy consumption due to heat generation: less than 4.0 kWh per year
  • Direct cost reduction: 1,700 Euros.