The Commission is in the process of updating some of the content on this website in light of the withdrawal of the United Kingdom from the European Union. If the site contains content that does not yet reflect the withdrawal of the United Kingdom, it is unintentional and will be addressed.

Ironworks Acroni

Τόνισε Περίπτωση January 2012
Share this Post:
Ironworks Acroni in Slovenia is a good practice example of improved indoor lighting efficiency based on an energy performance contract.

The existing structure of the ironworks has a very old indoor lighting system, approx. 30 - 50 years.  There are very low light levels in four workshops (120.000 m²) in the range of 30 - 100 lux. It also has high installed lighting electric power: 2.069 kW and high electricity consumption for lighting: 16.977 MWh/year


  • Significant improvement of working conditions, in terms of lighting, in line with legislation
  • Lower energy consumption and cost savings
  • Introduction of continuous monitoring and operating optimisation of the indoor lighting system


Measures (selection):

  • Replacement of lighting electric installation (1.11.2004 - 1.10.2007)
  • Installation of new metal halide luminaries equipped with low-loss magnetic ballast (instead of HP Mercury luminaries with high-loss magnetic ballasts) in 4 workshops (120.000 m²)
  • Setting up smart electricity meters
  • Introduction of lighting energy management module

The energy performance contracting model (EPC) realised at Acroni consists of implementation of the functional energy and cost efficient indoor lighting system in 4 working shops comprising planning, financing, installation, service and maintenance for 5 year contract term (31.10.2009 – 30.9.2012).



  • Lighting quality improved significantly (upgrade from 30-100 lux to 300-500 lux)
  • Lighting electric power after refurbishment: 975 kW (52% reduction)
  • Electricity consumption after refurbishment: 7.756 MWh/year (guaranteed 54% savings)
  • Electricity savings: 9.221 MWh/year (guaranteed savings)


Author(s) information


Damir Staničić

Lessons learnt

Lessons Learned, Innovations and Client’s Advantages: 1. Implemented efficient lighting measures enabled energy and cost savings in range more than 50% (up to 60%, pay back times 2-4 years – depending on electricity price) and fulfilled all legislative requirements in terms of light level at working places, adding non- energetic benefits (easier maintenance, management, productivity, comfort…). 2. New techniques of energy management (monitoring and targeting) were introduced based on refurbished data acquisition system and introduced new operating protocols. 3. Based on positive experience gained through the energy performance contracting project (EPC), the client has decided to performance contracting project (EPC), the client has decided to continue with the refurbishment of the lighting system and EPC.

Award labels

Available link languages


reporting by Damir Staničić, Energy Efficiency Centre, Jožef Stefan Institute, Ljubljana, April 2011