Like many other areas, the power production centers are far from the consumer centers in Brazil, says Jorge Bauer, a director in Brazil State Grid. Therefore, people are in need of very useful technology to reduce energy losses while transmitting electricity.
Alternate Current (AC) transmission is not suitable here because the wire resistance will generate considerable heat over the long journey, resulting in a huge loss of energy. To solve this problem, Brazil adopted Ultra High Voltage (UHV) technology from China.
For people who don’t know much about UHV, workers like Paulo Chaves in Brazil State Grid are fearless since their workplace is at a height of 57 meters and they tread on aluminum cables transmitting energy at 800,000 volts, double the voltage of conventional lines. But their work is very important as these power lines deserve special care.
Take the 2,000-kilometer long line that connects the Amazon Forest and Rio as an example. It has to deliver 4,000 megawatts of energy to feed 70 percent of the power Rio needs. Whether Rio can embrace more renewable energy is determined by the transmission.
In this case, Direct Current (DC) is a better choice for the long-distance job. At converter stations, voltage will be raised to 800,000 volts, which qualifies as Ultra High Voltage, and heads to the destination. After thousands of kilometers of transmission, DC arrives at the converter station, where all systems are instantly engaged to convert it back into AC. Then it is transferred to the local grid in Rio. Eventually, Ultra High Voltage will be reduced and used by the consumers.
With this new technology, energy losses while transmitting this kind of energy will be reduced to a large extent and it is the most efficient way so far, said Bauer. It is really a masterpiece of engineering.
To know more stories about carbon neutrality, check out the rest of CGTN’s documentary Human Carbon Footprint.