Brazil´s power network consists overwhelmingly of hydroelectric plants which generate 76% of electricity consumed in the country. Brazil has an immense reserve of hydrographic basins. These plants are classified by their power and represented by the terms:

• HEP (Hydroelectric plants) - power above 30 megawatts (MW)
• SHP (Small Hydroelectric plants) - from 1 to 30 MW
• HGC (Hydroelectric Generation Centers) - to 1 MW

The hydroelectric plants are regarded as an alternative way of generating energy at an excellent cost-benefit. The electricity generated is cheap and has little impact on the environment as it depends on a renewable source (water) and does not emit polluting gases as it does not burn fossil fuels. The biggest impacts from this type of plant are on the local ecosystem due mainly to the large reservoir which is formed.

After Brazil was affected by an energy blackout in 2001 and 2002 - resulting from the lack of investments in the sector and a period of drought - thermal electric plants were given a great boost. Other factors also encouraged this expansion, such as the increased supply of natural gas, difficulties in obtaining environmental licenses for large hydroelectric plants and the diversification of the network, amongst others.

Renewable sources, such as biomass (sugar cane stubble, sawdust etc.) and wind-powered plants) have also increased in Brazil. Such investments are only possible thanks to the decentralizing of the sector which began in 1995 with the program to privatize the distribution, generation and transmission companies. In 2008, the federal government announced that it intended restarting Brazil´s nuclear program with the aim of building dozens of nuclear plants in the coming decades.

Learn how electrical energy is generated

The purpose of a plant is to transform one thing into another, for example, an alcohol plant transforms sugar cane into alcohol. It is the same with energy plants. The function of a hydroelectric plant is to transform the movement of the river (kinetic energy) into electricity (electrical energy). But how is this done?

When the river water passes through the turbines, it turns their blades and activates the generator. The basic electricity generation process inside occurs through the rotation of a series of magnets inside metal spirals. This process moves electrons and produces an electric current.

Once the water passes through the turbines it goes through an escape channel and returns to the river. The faster the water passes through the turbines, the more electrons are moved and more energy is generated. Building dams creates an obstacle in the river which increases the speed of the water passing through the turbine and allows even more energy to be generated.

Other ways of generating energy

As Brazil has a large number of rivers, 76% of its energy is produced by hydroelectric plants. Despite this, there are other popular means of generating energy throughout the world:

Thermal

The thermal plants which are common in Europe and North America generally use fossil fuels to force the air to move the turbine blades which activate the generator as they do in hydroelectric plants.

Nuclear

In the process of nuclear fission, the atomic nucleus of a material may be subdivided into two or more particles, releasing energy. The fusion of uranium is used throughout the world as an alternative to thermal generation.

Wind

The energy which comes from the wind uses the same principle as hydroelectric energy. In this case, an aerogenerator is used instead of turbines. The structure looks like an enormous windmill.

Brazilian power infrastructure

The National Electrical Energy Agency (Aneel) says that more than 1,900 companies operate in power generation in Brazil. The infrastructure consists of more than 160 hydroelectric plants, 990 thermal plants, 330 small electrical generation centers, 270 electrical generators and 20 wind plants, as well as one solar and two nuclear plants. In 2008, the federal government restarted construction of the Angra III nuclear plant.

The largest company in the sector in terms of installed potential, which is the energy-generation capacity measured in megawatts (MW), is Companhia Hidro Elétrica do São Francisco (Chesf) with 10,615 MW, around 10% of domestic capacity.

The generation of electrical energy in Brazil is concentrated in the hands of the Eletrobras group. This is a mixed company, listed on the stock market, in which the federal government holds a controlling stake. Almost 40% of Brazil´s installed capacity is under the control of Eletrobras.

Almost the entire power generation and transmission system in Brazil is connected to the National Interlinked System (SIN) which is controlled by the National Electric System Operator (ONS), a statutory non-profit body created on August 26, 1998.

The Brazilian electricity sector is regulated and inspected by the National Electrical Energy Agency (Aneel).



Plants

The main large hydroelectric plant in Brazil is Itaipu - located on the River Paraná on the border between Brazil and Paraguay - which has a total potential of 14,000 MW. However, 50% of the energy generated is destined for the neighboring country. Therefore, the largest plant which generates power exclusively for Brazil is Tucuruí, with a potential of 8,370 MW. The Santo Antônio plant will have 3,150 MW of installed potential and be the third-largest in the country in terms of assured energy.

The largest thermal electric plant is Governador Leonel Brizola in Duque de Caxias (RJ), with a total potential of 1,058 MW provided by natural gas. The thermal electric plants are responsible for 24% of Brazil´s total potential.

The country has two nuclear plants, Angra I and II, both located at Angra dos Reis on the coastline of Rio de Janeiro state. These plants produce electrical energy through nuclear reactions of radioactive materials. Angra I has generating capacity of 657 MW and Angra II of 1,350 MW.


The largest operating plants in Brazil

Position	Plant	Potential (MW)	Type of Generation	Owner	State
1	Tucuruí I and II	8.370	Hydroelectric	Eletrobras Eletronorte	PA
2	Itaipu (Brazilian Part)	7.000	Hydroelectric	Itaipu Binacional	PR
3	Ilha Solteira	3.444	Hydroelectric	Cesp	SP and MS
4	Xingó	3.162	Hydroelectric	Eletrobras Chesf	SE and AL
5	Paulo Afonso IV	2.462	Hydroelectric	Eletrobras Chesf	AL and BA
6	Itumbiara	2.081	Hydroelectric	Eletrobras Furnas	MG and GO
7	São Simão	1.710	Hydroelectric	Cemig-GT	MG and GO
8	Gov. Bento M. da Rocha Neto	1.676	Hydroelectric	Copel	PR
9	Jupiá	1.551	Hydroelectric	Cesp	SP and MS
10	Porto Primavera	1.540	Hydroelectric	Cesp	MS and SP
16	Angra II	1.350	Thermal-Nuclear	Eletronuclear	RJ
24	Governador Leonel Brizola	1.058	Thermal Electric	Petrobras	RJ

Eletrobras

In 1954, President Getúlio Vargas proposed the creation of Eletrobras (Centrais Elétricas Brasileiras) as a state-controlled group of companies in the electrical energy sector but it only came into being in 1962. The company assumed responsibility for developing projects and operating generation plants, transmission lines and sub-stations across the country. From 1990, ongoing privatization processes and institutional reforms led to a change in its profile. Eletrobras is now a mixed company with its shares listed on the stock market. The federal government owns 54% of the common shares and controls the company. New sector regulations introduced in 2004 excluded Eletrobras from the National Privatization Program (PND).

The companies within the Eletrobras group have installed capacity of more than 37,000 MW, almost 40% of the domestic total. The company has six subsidiaries: Eletrobras Chesf, Eletrobras Furnas, Eletrobras Eletrosul, Eletrobras Eletronorte, Eletrobras CGTEE and Eletrobras Eletronuclear..


Aneel

The National Electrical Energy Agency (Aneel) is an agency linked to the Ministry of Mines and Energy (MME) and was created in 1996 after the privatizations in the sector to oversee favorable conditions for the electrical energy market and ensure it developed in way which balanced the interests of the operators and benefited society as a whole.

The agency´s main tasks are::

• To regulate and inspect the generation, transmission, distribution and sales of electrical energy;

• To mediate in conflicts of interest between the operators and consumers in the electricity sector;

• To grant, permit and authorize the construction and exploration of electrical energy installations and services;

• To ensure fair prices and encourage quality of service;

• To require investments and encourage competition among the operators and ensure that services are available to the entire population.
Sources: Aneel, Eletrobras, ONS, Análise Energy 2008 (Análise Editorial), Eletrobras Furnas, CCEE (Câmara de Comércio de Energy Elétrica).


Graphs and tables

Operating plants





The 10 Operators with the Greatest Installed Capacity in Brazil (Plants in Operation)

N°	Sector Operators	Installed Potential (kW)
1°	Companhia Hidro Elétrica do São Francisco - CHESF	10.615.131
2°	Eletrobras Furnas - FURNAS	9.456.900
3°	Centrais Elétricas do Norte do Brasil S/A - ELETRONORTE	9.256.933,10
4°	Companhia Energética de São Paulo - CESP	7.455.300
5°	Itaipu Binacional - ITAIPU	7.000.000
6°	Tractebel Energia S/A - TRACTEBEL	6.965.350
7°	CEMIG Geração e Transmissão S/A - CEMIG-GT	6.782.574
8°	Copel Geração e Transmissão S.A. - COPEL-GT	4.542.104
9°	Petróleo Brasileiro S/A - PETROBRÁS	4.464.356,60
10°	AES Tietê S/A - AES TIETÊ	2.651.350