module 1 LISTENING DISTRIBUTION SYSTEM COMMUNICATION Complete the text using the words in the box. companies consumers demand high lower network power plant provides substation transformers transmission voltage volts Electric power serves every home, farm, store and factory. Electricity must be transmitted from the (a) .......................... to a certain city or area and from there it must be distributed to the different (b) ........................... It is usually transmitted at the highest (c) .......................... possible in order to minimise energy losses from the heating of conductors and to economise on the material needed for conductors. (d) .......................... lines for alternating current using voltages as high as 765,000 volts are very common. Recent advances have made it possible to have transmission lines that operate at 800,000 (e) .......................... and above. Such lines are still very expensive, however. Most electric power (f) .......................... operate a number of generating stations at various locations throughout a particular region. The transmission lines of one station are usually connected in a (g) .......................... to the lines of the company s other stations to meet the unexpected (h) .......................... for additional electric power. The transmission system of many electric power companies are also linked to each other. This interconnected network of lines is called a grid which (i) .......................... pools of electric power. Each system usually has spare generators that can supply power as needed. The voltage of transmission lines is too (j) .......................... for local users. When electric power reaches the area where it will be used, step-down transformers (k) .......................... the voltage. At the distribution substation, it is lowered again; some industries receive current directly from the distribution (l) .......................... while homes and offices need current at even lower voltage, usually from 120 to 240 volts. This voltage is obtained through small (m) .......................... fastened to the poles that support the electric power wires running to individual users. Power substation High voltage transmission lines Step down transformer GLOSSARY to fasten: assicurare loss: perdita pool: riserva spare: in più, di scorta 36 Transformer Power poles Transmission substation Power plant