Electricity is transmitted from power stations to the point of final consumption through electric cables and transformers. During this transmission, power loss occurs due to copper loss and iron loss. Copper loss occurs due to the Joule effect. When an electric current flows overcoming the electrical resistance of the conducting cable, some fraction of electricity is converted into heat and lost. The amount of copper loss is estimated to be about 5% of the total power demand. Iron loss refers to the power loss caused by the iron core material in a transformer, and the amount of this iron loss is estimated at about 1% of the total power demand. Motors and transformers are also used in the final stage of converting electrical energy. Here again, copper loss and iron loss are incurred in the material used for these devices. The power loss attributable to iron losses at this stage is estimated to be 2.4% of total power demand. In consequence, the total iron loss amounts to 3.4% of the total power demand. The annual power demand is 850 billion kWh in Japan and 11,750 billion kWh in the world (statistics from THE INSTITUTE OF ENERGY ECONOMICS, JAPAN, 1990). Therefore, the annual power loss due to iron losses is equivalent to approximately 29 billion kWh in Japan and approximately 400 billion kWh in the world. The amount of power lost in the whole of Japan is equivalent to 1.5 times the annual power generated by Kashima 4.4GW Thermal Power Station, the largest power station in Japan. Power loss caused by iron losses can be reduced by improving electrical steel sheets. The figure shows the past year's record regarding the iron loss value of electrical steel sheets for transformers, taking the highest-grade products as an example. The iron loss value varies depending on the saturation magnetization and frequency of alternative current, but the values shown in the figure are those obtained at a saturation magnetization of 1.5 tesla and a frequency of 50 Hz. In the period from 1940 to 1960, iron losses were greatly decreased through the development of grain-oriented electrical steel sheets with controlled crystal orientation which made it possible to secure silicon contents as high as 3.25% with no significant decrease in saturation magnetization. Subsequently, iron loss continued to decrease, thanks to the practical application of technology for reduced impurity element concentration in steel, improved insulating films, reduced steel sheet thickness, and other improvements. Iron losses were decreased further through higher integration of crystal orientation in the 1970s and the practical application of technology for refining the magnetic domains to decrease hysteresis loss in the 1980s. Such a decrease in the iron losses of electrical steel sheets has also greatly contributed to down-sizing and to the efficiency of motors for home appliances, including refrigerators, washing machines, and air conditioners, and has resulted in decreased power loss during the transmission of electric power. It is expected that a further decrease in the iron losses of electrical steel sheets will contribute greatly to achieving "sustainable development", and will thereby improve human life while saving energy resources and producing less environmental pollution.