Why it is important to integrate active and passive energy efficiencies?

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Article Summary

In this article we will discuss the differences between passive and active energy efficiencies and how important the integration between them to the success of any energy management system in different areas.

Passive energy efficiency

  • There are two distinct approaches to energy efficiency. Passive energy efficiency depends on devices and materials that intrinsically use less energy to perform their function. Examples include replacing existing equipment with lower consumption devices, fixing leaks and adding insulation.
  • Oftentimes energy efficient lighting upgrades for buildings or upgrading pumps control system with VSC (variable speed control) in industrial applications are among the first projects undertaken, largely because of their quick return on investment. Also, adding insulation in major heat loss areas is one of the easiest and most effective areas for improvement.
  • These actions are called ―passive because once implemented, they silently save energy as they are used.
  • Passive energy efficiency can generate savings of 10% and 15%, but there is more to do. An energy efficient light bulb will still waste energy if it is left switched on when it is not needed.
  • Insulation will not save money if people open the windows and let heat out during the winter, or let cold air out during the summer.


Active energy efficiency

  • Active energy efficiency is needed to maximize and sustain the gains from passive energy efficiency, and bring additional savings too.
  • Active energy efficiency seeks to use energy more intelligently, to achieve the same results with less. Through automation and regulation you can ensure that equipment only works as hard as it needs to and not more.
  • Many of these measures are relatively easy to implement and pay back in less than 2 years. Lots of energy efficiency programs start by improving employee awareness and behavior – such as shutting down production equipment and lighting when not in use to reduce energy.
  • That’s a good way to start at little or no cost, but it leaves you vulnerable to human errors. Automation reduces that risk, turning off devices when not needed and regulating motors or heating at the optimized level.
  • A permanent monitoring and maintenance program locks in the savings. Monitoring also gives you the information you need to find more savings.
  • We can see the effects of combining these approaches in the below diagram as you could save 10 to 15% of your consumption with passive energy efficiency measures dealing with efficient devices and installation and you could take that further with automation and regulation to optimize the usage of those devices – another 5 to 15%. Then, your monitoring program could bring another 2 – 8%, by noticing deviations and allowing you to correct them quickly.


  • Depending on your facility, you could readily save 30%, However, you can lose these savings quickly if you don’t keep your monitoring and maintenance program in place.
  • Automated systems can drift away from optimal performance as small adjustments are made over time and People can slip back into energy-wasting behavior if deviations are undetected and expectations are not reinforced.
  • Power reliability is also an important contributor – efficiency gains can be lost quickly if there are unplanned, unmanaged shutdowns of equipment and processes. Without proper monitoring, each year 8% of savings can be lost.

Magdy Aly

Energy manager, Energy efficiency consultant Passionate to help others to save Energy and Environment.

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1 Response

  1. Kailin says:

    Times are chgainng for the better if I can get this online!

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