Efficient transmission and distribution of electrical energy
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Transmitting energy over distance implies loss |
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by Raymond Cordelier, former IEC Technical Director
Growing populations and developing countries that are modernizing create huge needs for electrical energy. Unfortunately, electricity is not always used in the same place that it is produced, meaning long-distance transmission lines and distribution systems are necessary. But transmitting electricity over long distances and via networks involves energy loss.
So, with growing demand comes the need to minimize this loss to achieve two main goals: reduce resource consumption while delivering more power to users. This can be done in at least two ways: deliver electrical energy more efficiently and change consumer habits.
Transmission and distribution of electrical energy require cables and power transformers. In these elements energy losses are generated by three things:
- the Joule effect, where energy is lost as heat in the conductor (a copper wire, for example);
- magnetic losses, where energy dissipates into a magnetic field;
- the dielectric effect, where energy is absorbed in the insulating material.
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The Joule effect in transmission cables accounts for losses of about 2.5% while the losses in transformers range between 1 and 2 % (depending on the type and ratings of the transformer). So, saving just 1% on the energy produced by a power plant of 1 000 megawatts means transmitting 10 MW more to consumers, which is far from negligible if we consider that a home needs between 5 and 10 kilowatts.
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Changing consumer habits also involves learning to
switch off appliances |
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Changing consumer habits would involve awareness-raising programmes, often undertaken by governments or activist groups. From simple things, such as turning off lights in unoccupied rooms, or switching off the television at night (not simply putting it into standby mode) are but two examples among a myriad of possibilities.
On the energy production side, building transmission and distribution systems with higher efficiency is another way to go about it. High efficiency transformers, superconducting transformers and high temperature superconductors are new technologies which promise much in terms of electrical energy efficiency. Furthermore, new transmission techniques are being studied, such as direct current transmission and ultra high voltage transmission in both alternating current and direct current modes.
IEC technical committees work in all these fields, with the list including:
- TC 7, Overhead electrical conductors
- TC 10, Fluids for electrotechnical applications
- TC 11, Overhead lines
- TC 13, Electrical energy measurement, tariff- and load-control
- TC 14, Power transformers
- TC 17, Switchgear and controlgear
- TC 20, Electric cables
- SC 22F, Power electronics for electrical transmission and distribution systems
- TC 51, Magnetic components and ferrite materials
- TC 55, Winding wires
- TC 68, Magnetic alloys and steels
- TC 90, Superconductivity
- TC 112, Evaluation and qualification of electrical insulating materials and systems
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Technical Committee 113, Nanotechnologies, involves the IEC in a very promising field that could see important breakthroughs in the subjects of insulation and conductivity.
Ever since its creation in 1906 the IEC has developed standards that deal with electrical efficiency. As an example, at a meeting held in Paris in 1932, IEC Advisory Committee No. 2 (as the TCs were then known), and which at that time covered the entire field of electrical machinery, decided to set up a permanent subcommittee to consider the issue of “efficiency and losses”. Technical Committee 2, Rotating machinery, and TC 14, Power transformers, today continue that work by delivering the highest quality International Standards involving the best means of producing and providing electrical energy efficiently. |
