What is energy efficiency?

According to ISO standard 50001:2011, energy efficiency is defined as “a ratio, or any other quantitative relation, between performance, service, goods or an energy produced and an energy intake”. The improvement of energy efficiency is the reduction of energy used whilst keeping the same provided service or produced goods.

Environment and productivity

It is widely accepted that climate change and natural resources management are crucial for the wellbeing of our planet. A better management of resources and pollutants has become a priority for a majority of governments in the world as evidenced by Paris climate agreement (COP21).  

In order to reach its objective of reduction of greenhouse gas emissions (-20% for 2020), Europe must improve energy efficiency.  We are fall aced with these challenges in all areas of life and industry ; transport, construction, and especially industry.

Moreover, with the recovery of the economic growth, and in a increasingly competitive  global context, European industries can’t afford to neglect the important part that energy use in their operating costs plays.

Some numbers to illustrate those costs often hidden or overlooked:

  • compressed air leaks can represent up to 30% of power consumption linked to compressed air production.
  • failing bleeders can typically lead to the loss of 4 to 30 kg/h of steam and represent an extra annual cost of close to 1000 euros.
  • A 10 meter steam line not insulated can represent up to 1000 euros of annual loss.

Solutions exist to reduce such energy losses and issues. An energy audit is an important first step in order to identify appropriate solutions.

Energetic audit

The objective of an energy audit is to identify areas for improvement, prioitised by those with the biggest positive impact on energy efficiency and thereby financial savings.

The improvement actions  identified will include the “quick-wins” as well as energy improvements requiring more effort and planning. The quick-wins are any easy action to set up, bringing a near immediate result.

Typical improvement actions involve working on heat recovery, rational use of energy, detection of air leaks, isolation, insulation, optimized control of HVAC system, lighting and use of renewable energies.

 

Energy audit steps

In order to bring concrete solutions and results, the energy audit must be completed in a structured and methodical way.  The method followed by I-care is well established and proven in a wide range of industry:

  1. Energy performance survey
  • Evaluate the current energy performance
  • Define improvement actions
  • Identify quick-wins and more advanced energy improvements
  1. Current consumption analysis
  • Invoice analysis
  • On-site survey
  • Primary energy conversion and CO2
  • Consumption distribution
  1. Improvement tracks study
  • Potential savings calculation
  • Technical feasibility estimation

On the side or in the logical follow-up of an energy audit, several inspection services with associated energy losses calculation can be useful:

  • Air leaks detection by ultrasound
  • Steam trap inspection and fault identification
  • Gates tightness inspection
  • IR thermography (building, insulation, exchanger efficiency, etc)

Case study n°1 : compressed air leaks detection

Assumptions :

  • 20 /t
  • 8400h/year
  • # failing purgers : 10%/year
  • ports size average : 3 mm

Method : Ultrasound and vibration

Case study n°2 : infrared thermography

  • fluid : industrial steam
  • surface T° : 128
  • ambient T° : 20°C (still air)
  • conduct : L = 5m DN40

Energy losses : 6882 kWh/year or 218.35/year