When:
It is the first commercial HVDC transmission line in the world. The project has been in use since 1984 and completed in 1987. The complete version has been serving the Sao Paulo area since 1990. The Itapúa HVDC project is one of the largest HVDC overhead transmission projects in the world and one of the two main HVDC lines built by ABB to supply power to the industrial region in the southeast of Sao Paulo. After the first bipolar was built in 1985, it became the highest HVDC system in the world in terms of transmission capacity and voltage, a title it would hold for 25 years. The Xiangjiaba-Shanghai UHVDC line is still one of the largest HVDC transmission lines in the world, though it took the title from the Itapúa project in 2010 with a voltage of 800kV. The 6,300 megawatts of rated power that will carry Itapúa’s clean energy to Sao Paulo, some 800km away, will produce about 12,600 megawatts of electricity a year.
Scope:
Designed as a dual line 800km, the Itapúa HVDC is composed of two ±600 kV bipolar poles, each rated at 3,150 MW, which will transmit power generated at 50 Hz from the Paraguayan side of the Itapúa Dam (near Iguazu in Parana) to the 60 Hz grid in Sao Paulo and via the Ibiuna converter station in Sao Paulo.
At present, the project has been in operation for 35 years. Since 1990, the project has been operating at the designed voltage without any major accidents. It can be said that the project has been operating in accordance with the plan. This has put the project on the map and established it as the world’s leading technology owner for ABB’s substation systems, especially the UHVDC substation.
Successfulness:
The project was an indisputable success. Itaipu’s HVDC project, which is similar to the Quebec grid, is run by private companies. Its current operating business is Furnas Centrais Eletricas in Rio de Janeiro. As a private company, if the operating profit is less than the maintenance cost, the project will be shut down. Even though it seems that the substation technology is no longer the most advanced and safe, the project continues to operate. So economically and safely, the whole project is a success. Itaipu’s HVDC project was also successful because of a combination of the right time and the right place. Compared with Quebec, Brazil’s project is longer and has a single connection point. This makes the advantages of HVDC all the more obvious: cost is reduced by having fewer substations on a single point of connection over long distances and the advantages of lower HVDC consumption can be demonstrated.
The Itaipu Hydropower Plant is an excellent example of the establishment of HVDC transmission. A steady stream of electricity needs to be delivered to the densely populated areas of Sao Paulo without the need for any electricity from the separated parts of the substation. HVDC is like a high-speed railway: the fewer stops in the middle, the faster and less wasteful it can be to get electricity to the end. Since the cost and technical difficulties of HVDC are mainly found in substations, the Itaipu project in Brazil provides a perfect example of where only substations need to be built at the start and end points. (Chinese projects have built fewer substations than two per line, which is why China is still building a lot but spending much less than it used to.)
What can we learn from it?
Itaipu is an excellent example of a high voltage DC transmission line (single line). The simplicity of the design and the directness of the service made the project a success. In addition to building a smart grid in the European region, Supergrid also needs to build an ultra-high voltage DC link between its clean power production region in North Africa and Europe. For these projects we may be able to take inspiration from the Itaipu project in Brazil. When we build photovoltaic, solar thermal and wind power plants in North Africa, we might be able to first feed the electricity through an AC grid into a large substation, which would then be converted into ultra-high voltage direct current, which would be transmitted directly to the relatively central continental region of Europe. Because the amount of electricity generated is so large, it may be possible to build multiple transmission lines from the same origin (substation) to different destinations. Through the double-line-extension way, not only can reduce the number of substations, but also for the further extension of the EHV DC line, there is no need to carry on the transmission after the substation, reducing the loss rate.
At the same time as the world’s ultra high voltage DC substation technology ownership, Europe has Siemens and ABB two more developed technology companies. Over the years, smaller, lower loss, and higher safety systems have been built. This allows for a gradual reduction in floor space costs and, through smarter deployment to balance peak and trough usage points, Supergrid can be built with all the strengths and lessons of existing grids. North Africa’s clean energy is infinite compared with Itaipu’s hydroelectric plant, so it may require the construction of multiple lines. But Europe’s electricity consumption is not Sao Paulo’s single point either. Europe has a number of countries with a large span of countries and dense population areas. It would be a better plan to find a suitable center to build a large substation in the population center, and then rationally distribute the power transmitted by multiple UHVDC through the intelligent high-voltage alternating current network.