Light-Emitting Diode Lighting or the High-Pressure Sodium Arc Lamp

What is profitable: LED solutions or HPS: can these systems be compared to each other, and are they fundamentally different?
Comparing the lighting system between each other


On the first glance its urged to say NO!
For the existing lighting solutions with the HPS have drawbacks

  • Low effectiveness due to losses at the electronic ballast
  • Starter-regulator
  • Large component of the reactive power
  • High starting current
  • Impossibility to control the arc lamp power
Street Sodium lighter

There are “Electronic-Control Gears (ECGs)”.

These products totally qualify to standards of electricity consumption in accordance with IEC 60598, and support power control over the range from 0 to 100% in the automatic mode.

Demonstration of the HPS lamp controls with the ECGs

Lamp power changes with the programming method from 100% to 0.

The question arises: how relevant and justifiable is the use of such ECGs?!

Let’s take a look at the economic rates of the street lighting effectiveness:

All calculations are shown in reference to the existing analogues of the classic HPS with parameters:

  1. Choke VOSSLOH SCHWABE NAHJ 250.204 529087
  2. Lamp Philips SON-T APIA Plus Xtra 250 W
  3. Electronic Control Gear VOSSLOH SCHWABE VS-Power Ignitor Z400 M Ref. No. 147707
  4. Phase corrector - Capacitor VOSSLOH SCHWABE VSS25 500318

Sodium lighter

Let’s perform the analysis of listed components using the comparison chart (#1). Presented information is based on the calculations and analysis of the reliable market prices (including the open tender sources from “Prozorro”).

Chart # 1 Technical and economic comparison of the lighting sources considering 50% of the energy saving due to controls of the relatively classic HPS 250 W.

You can familiarize with more detailed calculations by downloading the file Download

Thus, project payback period of the existing HPS street lighting systems with ECG is almost 3x less than for the LED lighting.

Also, the major differences between LED and HPS should be given out:

  • Spectres of    HPS and LED:

  • LED effectiveness decreases when heated, but in HPS it increases
  • Warranty period of the modern lighting sources:
    1. HPS lamp is not less than 5 years, and due to controls and smooth start can increase almost twice.
    2. LED reach is up to 10 years, which is set by producers.
    3. HPS lamp is losing its effectiveness in time as much as LED.
    4. The use of acrylic lenses in LEDs in comparison to the aluminum HPS reflectors possesses serious drawbacks, such as effectiveness reduction during heating and ultraviolet radiation.
  • Overall size and weight:
    1. HPS luminaire HELIOS16 (for example) with ECG weights up to 4 Kg.
    2. Light-Emitting-Diode luminaire of 200 W weights 12 Kg and amounts to a big overall size. Thus, additional supports get installed and require additional spending. Currently, two luminaires get installed, and two additional points of suspension (gooseneck), in order to secure the necessary luminous flux.
  • Overall brightness
    1. HPS lamp has much less brightness (no blinding effect) than LED solutions and corresponds to all standards.
    2. LED has highly bigger overall brightness and can cause discomfort with the blinding effect
  • Light acceptance by the human eye:
    1. HPS works in the narrow orange spectrum, which secures high contrast and qualified visibility during a fog or rain.
    2. LED luminaire works in the wide spectrum, which brings it closer to the daylight, but at the same time increases the asphalt glare during rain and causes the fog background illumination in a form of a white circle.


  • LED luminaire is really demonstrating beautiful results with its effectiveness, but an excessive price in comparison to the guaranteed warranty period completely levels its advantages.
  • HPS with ECG: provides easy and cheap modernization of the existing HPS luminaires, protection system from contingency situations on the power line, can also automatically control power, increase operating time of the HPS lamp, and above all, the payback period stays within 3-5 years, when such period with LEDs is not less than 10 years.
  • As with LED luminaires, modernized HPS systems with ECG did receive the remote control possibility, so it provides dispatching of localities and power line monitoring.