Energy efficiency trickles down into large applications

Essential in energy-hungry domains such as industry and buildings

By Morand Fachot

Achieving better Electrical Energy Efficiency (EEE) is a very broad task that extends well beyond the more efficient transformation of primary energy, chiefly fossil fuels, into electrical energy. It must be introduced in energy-intensive sectors like industry and buildings. Standardization work by numerous IEC Technical Committees (TCs) is central to this broader objective. 

Electric arc furnace for steel production
Electric arc furnace for steel production are more efficient than gas furnaces (Photo: Deutsche Edelstahlwerke)

Electric motors

Increasing the efficiency of electric motors is probably by far the biggest and most affordable EEE opportunity that exists: more than 50% of all electricity worldwide is converted into mechanical energy by electrical motors.

IEC TC 2: Rotating machinery, prepares International Standards regarding specifications for rotating electrical machines used in motors, with the exception of traction motors for railway equipment, and motors and generators used in electric road vehicles, industrial trucks or aeronautics and space applications.

The biggest user of motors is industry, which accounts for 40% of global electricity use according to the International Energy Agency (IEA). Around 70% of this electricity is consumed by electric motors for machines, and by pumps, fans, compressors, etc. Yet over 90% of these motors are unable to adjust their power consumption to fluctuations in power demand, thus wasting precious energy. Changing to electric motors with variable-speed drives (VSDs) reduces energy consumption by up to 50%. The annual energy cost of running a motor is usually many times greater than its initial purchase price and energy savings quickly amortize the initial investment: the new motor basically pays for itself. 

The IEC developed the IEC 60034 or IEC 61800 series of International Standards that rank electric motors according to their efficiency classes. Regulators everywhere in the world have taken on board this classification system and made it part of their policies. 

Industry

In addition to motors, which drive the large majority of production processes and consume around 70% of electricity used by industry, several other technology areas offer a good potential for increased EEE. 

Heating and cooling

Around 20%, and in some industries up to 40%, of electricity is used in heating processes. These are deployed widely across many sectors from food processing and automotive applications to smelting. Electro heating offers many benefits over processes that use combustion of fossil fuels. Higher efficiency is just one of them; cleaner air, higher temperatures and better process control are among the others. The optimum energy efficiency of gas furnaces ranges from 40 to 80%, while that of an electric furnace can reach 95%.

IEC TC 27: Industrial electroheating and electromagnetic processing, plays a central role in preparing International Standards, including EEE criteria for electroheating installations.

Technologies used include, among others:

  • Induction furnaces that melt various metals including steel, copper and aluminium, with absolute temperature control
  • Resistance heating for heat treating, forming, melting and drying metals; for cooking, sterilizing and roasting in the food industry or for firing and drying ceramic products
  • Plasma torches for cutting steel plates
  • Microwaves for treating food products
  • Radio-frequency electric fields for drying textiles, fixing dyes, controlling moisture content and also for sterilizing medical equipment
  • Lasers for welding, cutting and treating various metals
  • Infrared and radiation heating for coating and curing surfaces

Automation

In a very real sense, automated systems for smart manufacturing will pave the way for more energy efficient processes. They cover the whole life cycle of a product from idea to order, manufacturing and development, delivery and recycling, including all related services, as well as the integration of user or consumer input and feedback. 

IEC work largely covers the process and plant floor. IEC TC 65 publishes the International Standards that address the safety and efficiency of equipment and processes and the regulatory compliance and energy consumption, as well as the many protocols and methods that support the full range of communication, monitoring, control, safety and cyber security technologies in the area of automation. Many other IEC TCs publish the Standards that are needed for sensor networks, localization and tracing technologies, batteries, piezo-electrics, actuators, 3D printing, lasers and much more. 

Cutting buildings’ energy hunger

Commercial and residential buildings account for about 40% of primary energy consumption in many countries. This energy is used for lighting, heating, ventilation and air conditioning systems, as well as for powering elevators, escalators, machinery and appliances. 

Building automation

Building automation and control can improve the energy efficiency of buildings significantly. They include a wide variety of technologies that are connected wirelessly, including light detectors, timers, temperature, motion, humidity and many other sensor systems, as well as programmable logic controllers. Building automation can help optimize device use by switching devices off entirely or by reducing their use to the minimum. It can also highlight “bad habits” that should be corrected. For example by modifying the heating or cooling temperature settings by 2⁰C, up to 10% of energy can be saved.  Additional energy savings can be achieved by upgrading and renovating a building's wiring and by installing low-consumption, high-efficiency lighting systems, more efficient motors and transformers.

A number of IEC TCs are developing Standards that help achieve better EEE.

IEC TC 8 focuses on overall systems aspects of electricity supply. IEC TC 57 deals with communications between equipment and electricity systems. IEC TC 47: Semiconductor devices, develops Standards for sensors and similar devices. ISO/IEC JTC1/SC 25: Interconnection of information technology equipment, covers building automation including energy harvesting. 

Heating and cooling

Heat pumps represent one of the most efficient means of heating or cooling a building. They require a minimum amount of electricity to function and work on the principle of transferring heat from water, air, soil or other sources to provide heating, hot water or air conditioning. Some Standards in the IEC 60335 series, developed by IEC TC 61: Safety of household and similar electrical appliances, provide specific requirements for heat-pumps, air-conditioners and dehumidifiers. 

Moving people around

Elevators and escalators account for up to 10% of energy use in buildings. Innovative motors, using VSDs, and regenerative braking systems that recuperate energy help cut elevator power consumption in half. Escalators can be made more efficient by mounting sensors that turn them off when they are not needed or that activate soft start systems when the number of people carried is low. IEC TC 2, IEC TC 3: Basic and safety principles for man-machine interface, marking and identification, and IEC TC 47 provide the technical foundation that ensures that elevators and lifts work as efficiently and safely as possible. 

Lighting

Nearly 20% of total electricity production is consumed by electric lighting. By 2030, energy demand for artificial light is projected to be 80% higher than it is today.

The introduction of more energy efficient lighting solutions is seen as a priority in many countries.

Here as elsewhere, the choice of technology makes a big difference in terms of EEE. Incandescent bulbs waste about 95% of electricity, mostly in the form of heat. Compact fluorescent lamps are 80% more efficient than incandescent bulbs and have been a good tool to reduce energy consumption in this area.

LEDs represent the highest energy efficiency levels currently available commercially, reaching around 95%. LEDs find increasing application in street lighting systems and in large transportation hubs like train and underground stations or airports, where they can save up to 95% of energy in comparison with other technologies. Such savings generally help amortize the investment in a few years. They also find increasing application in low-power situations, for example off-grid or with batteries. 

LEDs are complex electronic assemblies; in order for them to deliver on their efficiency and long-life promise, they need to be built with reliable components and to be quality tested. IECQ, one of the IEC Conformity Assessment Systems, offers a dedicated programme for the testing and verification of LED components and assemblies.

IEC TC 34: Lamps and related equipment, prepares the large majority of International Standards for safe and efficient lighting, including performance requirements, specifications, testing and measuring methods for all types of lamps and their auxiliaries. Their scope includes lamps/lighting equipment used in homes, medical facilities, offices, road and street lighting, commercial and other buildings, and for emergency lighting, etc. 

Light management systems help switch lights on and off and regulate levels of lighting depending on weather and time of day. They can reduce energy waste significantly. IEC TC 23: Electrical accessories, and IEC TC 47 prepare the Standards that apply to electronically activated switches and sensors.

EEE is very significant in large energy-hungry applications, but it must extend also to other domains that touch individuals directly, such as consumer goods, individual and public transport or the ways cities will be designed in the future.

Gallery
Electric arc furnace for steel production Electric arc furnace for steel production are more efficient than gas furnaces (Photo: Deutsche Edelstahlwerke)
Siemens energy-efficient electric motor Energy-efficient motor (Photo: Siemens press picture)
KONE elevator EcoDisc drives Current KONE elevators EcoDisc drives use 50% less energy than previous class (Copyright: KONE Corp.)