Energy efficiency to recover power for the future

IEC work helps tap the biggest pool of available energy

By Morand Fachot

Energy efficiency (EE) is the most important and easily available source of energy; it can be collected along the entire energy chain, from generation, transmission and storage to final use in industry, homes or transportation. IEC standardization and conformity assessment (CA) work are central to electrical EE at all levels. 

Geothermal energy plant Geothermal energy plant at The Geysers near Santa Rosa, California, USA (Photo: NREL)

Dual approach

There are essentially two ways of improving EE

  • Selecting technologies that are more efficient in converting primary energy (fossil or nuclear fuels, biomass and renewable energy sources) into useful power, including electricity. This aspect is often not taken into account when considering energy efficiency.
  • Achieving the same outcome by using less energy.

Improving EE means also being able to measure the energy consumption of a device, system or process. This is achieved through data collection and analysis as well as by testing and verification. A well-defined set of criteria and metrics is indispensable for achieving meaningful and comparable results. For electrotechnology products, these are often incorporated in IEC International Standards.

Energy generation, storage, transmission, distribution

Converting primary energy into electrical energy can range from a very efficient process to others that are more wasteful.

The most efficient source of electricity is hydropower. Modern hydraulic turbines can convert 90% or more of energy from water into electricity.

By contrast, burning fossil fuels to produce electricity can be very wasteful. In older thermal plants, converting fossil fuels (coal in particular) into electricity can waste 2/3 of the primary source of energy. Thermal power plant can be made more efficient through combined heat power (CHP) use. 

Renewable energy sources include, in addition to traditional hydropower (which makes up some 85% of the total from renewables), geothermal, wind, solar (photovoltaic [PV] and thermal), marine energy conversion (wave, current, tidal). Owing to the intermittent nature of some renewables, hydropower, acting as storage available instantly, plays an important role in balancing production and ensuring grid stability. The following IEC technical committees (TCs) develop International Standards for power generation systems:

  • TC 4: Hydraulic turbines
  • TC 5: Steam turbines (used in geothermal, electricity generation from fossil and nuclear fuels, solar thermal electric plants and CHP)
  • TC 82: Solar photovoltaic (PV) energy systems
  • TC 88: Wind energy generation systems
  • TC 114: Marine energy – Wave, tidal and other water current converters
  • TC 117: Solar thermal electric plants

Storing electricity is important for energy efficiency projects by optimizing output from intermittent sources. In addition to hydropower, secondary (rechargeable) batteries are the main source of electrical energy storage (EES). Standards for these are developed by:

  • TC 21: Secondary cells and batteries, for all types of batteries used in EES including stationary (lead-acid, lithium-ion and NiCad/NiMH) batteries and flow batteries
  • TC 120: Electrical energy storage (EES) Systems, which develops International Standards in the field of grid integrated EES Systems, focusing on system aspects rather than energy storage devices

Transmission and distribution are other areas where better efficiency can be achieved. IEC International Standards provide the performance and test requirements that help assess the efficiency of all types of cables (developed by TC 20), overhead lines (TC 11) and overhead conductors (TC 7) . They help calculate losses and provide important parameters for cable design and installation. Important new technologies such as high voltage DC (TC 115) and ultra high voltage AC (TC 122) transmissions are made safe through IEC work. This highly sophisticated technology can help reduce transmission losses over long distances by up to 30%.

Transformers are another area where IEC work helps reduce power losses and, indirectly, carbon emissions. TC 14 develops Standards in the field of power transformers, tap-changers and reactors for use in power generation, transmission and distribution. It has published IEC TS 60076-20:2017, which proposes two methods of defining an energy efficiency index and introduces three methods of evaluating the energy performance of a transformer.  

So-called microgrids and off-grid rural electrification help reduce transmission losses by avoiding the need to transmit electricity over long distances.

Electricity is used for countless applications in industry as well as in buildings and in the domestic environment.

Industry as prime consumer…

Industry accounts for 40% of global electricity consumption, of which around 70% is consumed by electrical motors that convert electricity into mechanical energy for machines, and also by pumps, fans, compressors, etc.

Over 90% of electrical motors cannot adjust their power consumption to meet fluctuations in power demand, thus wasting precious energy. Improved motor control and motor efficiency mean greater overall production efficiency. Changing to electric motors with variable-speed drives can reduce 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 energy-efficient motor basically pays for itself.

TC 2: Rotating machinery, has developed International Standards that rate electric motors according to their efficiency classes and IECEE, the IEC System for Conformity Assessment Schemes for Electrotechnical Equipment and Components, has put in place the IECEE Global Motor Energy Efficiency Programme (GMEE).

In addition to motors, which drive the large majority of production processes, several other technology areas offer a good potential for increased energy efficiency.

Around 20% of electricity (up to 40% in some industries) is used in heating processes. These are employed widely across many sectors from food processing and automotive applications to smelting. Electroheating offers many benefits over processes that rely on the 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%, that of an electric furnace can reach 95%.

International Standards for electroheating are developed by TC 27.

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, construction and development, delivery and recycling, including all related services. TC 65 develops 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.

…but don’t forget buildings

In addition to industry, buildings – for commercial and residential use – are heavy energy users. They account for about 40% of primary energy consumption in many countries. This energy is used for lighting, heating, ventilation and air conditioning (HVAC) systems, as well as for powering elevators, escalators, machinery and appliances.

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.

TC 8 focuses on overall systems aspects of electricity supply. TC 57 deals with communications between equipment and electricity systems. TC 47 develops Standards for sensors and similar devices.

Heating and cooling require a significant amount of energy. 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 hot water or air conditioning. TC 61 develops Standards that provide specific requirements for heat pumps, air conditioners and dehumidifiers.

Elevators and escalators are energy-hungry systems, they account for up to 10% of energy use in buildings. Innovative motors 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.

Electric lighting consumes a significant amount of electricity, estimated at nearly 20% of total electricity production. The choice of technology makes a big difference in terms of electrical EE. Incandescent bulbs waste about 95% of the energy they use in the form of heat. Compact fluorescent lamps are 80% more efficient than incandescent bulbs, but lights based on light-emitting diode (LED) are up to 95% efficient converting electricity into light. TC 34 prepares most International Standards for safe and efficient lighting, including performance requirements, specifications, testing and measuring methods for all types of lamps and their auxiliaries. Other IEC TCs, such as TC 23 and TC 47, develop Standards that apply to electronically-activated switches and sensors.

Consumer goods are getting ever more energy efficient too!

TC 59 develops International Standards that address the energy efficiency characteristics of household appliances such as dishwashers, laundry appliances, cooking, fridge/freezers and many more. Among other things, these Standards are the basis for measuring and testing performance and power consumption, including in standby mode.

TC 100 provides standard measurement methods for the power consumption and energy efficiency of audio, video and multimedia systems, as well as other equipment connected to the power mains. These methods also cover applications for home energy management applications.

Energy efficiency claims made by manufacturers need to be verified independently. Such verification is done by independent laboratories, many of which also participate in IECEE.

Transportation now embarked on major electrification drive…

Internal combustion engines (ICEs), still the main mode of propulsion for road vehicles, are getting more and more fuel-efficient through the increased use of electronics systems. However, the most significant energy savings will come from making a move from ICEs to electric drivetrains or fuel-cells to power motors. The work of TC 21, TC 23, TC 69 and TC 105 supports the introduction of electric, hybrid or fuel-cell vehicles, covering the full range of relevant electric and electronic technologies, including batteries and charging infrastructure. The electrification of public transport is well advanced in urban environments with the introduction of electric buses in addition to existing tramway and trolleybus lines. Rail transport is also being increasingly electrified in many countries. TC 9 is tasked with the standardization of energy management systems in trains, metros, trams and similar transport applications. Electric vehicles are also found in many industrial applications, such as in warehouses (forklifts) and  airports (aircraft tow trucks). All of this helps accelerate the transition to cleaner, more EE transport systems.

For shipping, TC 18, TC 20 and TC 23 work on systems and technologies aimed at increasing EE in shipping. Their work supports the introduction of hybrid and full electrical propulsion systems, especially for short journeys, for example in harbours. 

New energy efficiency technologies

There is a rapidly increasing range of applications, including in the power sector, that use energy harvesting. This entails the process of collecting low levels of energy from sources such as ambient or waste heat, solar, thermal or kinetic energy and converting it into electrical energy. This trend is driven by sensors and wireless communication devices which aim increasingly to run independently from an external power source.  Most kinetic-based energy harvesting systems depend on piezoelectric transducers. International Standards for these are developed by TC 49.

Low-voltage direct current (LVDC) – a solution gathering pace

LEDs, cell and fixed phones, IT or multimedia equipment are able to use DC. Solar PV generates DC and yet – even in rural off-grid settings – this energy is transformed into alternating current. This results in unnecessary efficiency losses. 

LVDC is a low cost, simple but high-level technology that promises to bring energy to the millions who have none. It will help reduce conversion losses and eliminate the need to build many power transformers. LVDC will also make it easier to connect renewable energy.

The IEC is leading efforts to make this technology safe for use in rural electrification but also in data centres, hospitals, office buildings and other domains that use a lot of energy and would benefit from no losses in energy conversion. It set up a Standardization Evaluation Group (SEG 4) to evaluate the status of standardization in the field of LVDC applications and products and to recommend to the Standardization Management Board (SMB) the architecture of any future standardization work programme that the IEC may undertake.

Geothermal energy plant Geothermal energy plant at The Geysers near Santa Rosa, California, USA (Photo: NREL)
Solaris Urbino electric bus Tram and Solaris electric bus (Photo: Solaris)
convection/electroheating oven for automotive dashboards Convection/infrared electroheating oven for automotive dashboards (Photo: Infrared Heating Technologies)
PV modules PV modules (Photo: Courtesy of DuPont)