Practical considerations to achieve Energy Efficiency

From Electrical Installation Guide

Whilst it is currently possible to obtain energy savings of up to 30%, this potential reduction can only really be understood in terms of the differences which exist between active and passive forms of energy efficiency.

Active and passive energy efficiency

Passive energy efficiency is achieved by such measures as reducing heat loss and using equipment which requires little energy.

Active energy efficiency is achieved by putting in place an infrastructure for measuring, monitoring and controlling energy use with a view to making lasting changes. (see Fig. K10).

Fig. K10 – Energy efficiency solutions based on the life cycle

Savings from 5% to 15% may be easily obtained by implementation of passive energy efficiency. Typical measures include decommissioning redundant systems, use of high efficiency motors and lighting, Power Factor Correction. More significant savings can be achieved by implementation of active energy efficiency measures.


  • Up to 40% on energy for motors by using control and automation mechanisms to manage motorized systems,
  • Up to 30% on lighting by introducing an automated management mechanism based on optimal use.

Active energy efficiency does not require highly energy-efficient devices and equipment to be already installed, as the approach can be applied to all types of equipment. Good management is essential for maximum efficiency – there is no point in having low-consumption bulbs if you are going to waste energy by leaving them switched on in empty rooms!

It is important to remember, however, that savings may be lost through:

  • Unplanned/unmanaged downtime affecting equipment and processes,
  • A lack of automation/adjustment mechanisms (motors, heating)
  • A failure to ensure that energy saving measures are adopted at all times.

In addition, when the operator’s electrical network is expected to undergo frequent changes given the activities in which it is involved, these changes should prompt a search for immediate and significant optimization measures.

Approaches to energy efficiency also need to take other parameters into account (temperature, light, pressure, etc.), since, assuming energy is transformed without any losses, the energy consumed by a piece of equipment may exceed the useful energy it produces. One example of this is a motor, which converts part of the energy it consumes into heat in addition to mechanical energy.