Economy & Energy

No 23 December 2000 -

January 2001

   ISSN 1518-2932

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e&e No 23

Progress in the Energy Matrix and in the Emissions of Gases Causing the Greenhouse Effect

Main Page

Introduction

Reference Economic Scenario

Preliminary Evaluation for the 2000-2020 period

Demand in Equivalent Energy

Electric Energy Demand

2000 – 2020 Thermoelectric Generation

 

Participation of Fuels used in Generation  

Necessary Thermal Generation Capacity

Emissions in Thermal Power Plants

Conclusions and Sensitivity Evaluation

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1. Thermoelectric Generation in Public Power Plants

1.1 Electricity Generation and Fuel Participation

Provision of Electricity Demand

Projection of the resulting gross demand to be provided by imports, self-producer’s power plants and public power plants can be extracted from the previous item. These values are indicated in Figure 1.1 and Table 1.1. In the figure they are represented in comparison to their historical evolution.

  

Imports,    Self-producing Power Plants,     Public Power Plants

Figure 1.1: Provision of Gross Demand by electricity imports, production in self-producer’s power plants and public power plants.

                        

Table 1.1: Projected Gross Demand (TWh/year)                               

 

1995

1999

2001

2005

2010

2015

2020

Imports

35

37

43

44

46

49

59

Self-producers

15

18

26

28

35

43

52

Public Service

261

273

332

344

421

519

626

Total

311

328

401

416

502

612

737

1.2 Fuels Participation

The participation of energy sources in electricity generation and in generation itself is predominately hydraulic. The form in which hydraulic energy is accounted for in BEN (the energy necessary to generate electricity in a thermal power plant) renders the percent of source use close to energy production, excluding variations relative to efficiencies of generation by thermal power plants.

The predominance of hydraulic energy in electricity generation can be observed in Figures 1.2 and 1.3 in absolute and relative values for public power plants. The participation of thermal power plants has been decreasing since the start of the seventies due to the interconnection of the large consuming centers and the petroleum crisis in 1973 and 1979. In 1983 only 3% of the sources used for electricity generation in public power plants was thermal.

    

Consumption by Energy Sources for Electricity Generation in Public Power Plants

Hydraulic Energy / Nuclear/Fuel Oil /Diesel / Charcoal / Vapor Coal/ Natural Gas

Figure 1.2: Historical values of electricity generation from different energy sources.

The existing power plants were for a long period the reserve for deficiencies in the hydraulic system. With the establishment of the Cruzado Plan there occurred a consumption increase that was satisfied by generation from fuel oil. The power plants that use mineral coal either because they were coupled with nearby mines or because they consumed national fuel were maintained in the base.

The contribution from the Angra I nuclear plant, even though destined to provide for the base, had an irregular behavior due to technical problems.

Figures 1.3 and 1.4 show the participation of fuels by consumption of energy sources used in generation and in electricity generation, that has a very similar aspect as the former. In both of them data referring to public power plants are indicated. In Figure 1.4 only the participation of thermal power plants in electricity generation is shown.

  

Participation of Energy Sources for Electricity Generation

Hydraulic Energy / Nuclear/Fuel Oil /Diesel / Charcoal / Vapor Coal/ Natural Gas

Figure 1.3: Participation of the energy sources consumption used for generation in public power plants. It should be noticed that the vertical scale was reduced in 20% so that it would be possible to better show the participation of the thermal power plants (the hydraulic source adds to 100%).

 

Participation in Electricity Generation in Public Power Plants.

Natural Gas / Fuel Oil / Diesel Oil / Vapor Coal/ Charcoal

Figure 1.4: Participation of the conventional thermal energy sources for electricity generation in public power plants

 

Electricity Production by Energy Source – Public Power Plants

Nuclear/Fuel Oil /Diesel / Charcoal / Vapor Coal/ Natural Gas

Figure 1.5: Electricity generation from thermal power plants.

It is noticeable the use of fuel oil to provide for annual demand peaks since its retraction after the first oil crisis. From 1992 on one can see the consequences of changes in policies that hindered long-term investments and favored the use of thermal power plants.

1.3 Introduction of Thermal Power Plants 

The introduction of Public Thermal Power Plants was projected taking into account the general frame of Eletrobrás’ Decennial Plan 1998/2008 and up to 2001 the projects approved by ANEEL. The adopted procedure uses parameters that can be changed in order to study alternative hypothesis using the summary screen shown in the annex.

Evaluation of demand provided by public thermal power plants uses a participation "goal" in 2020 that considers the values of the last years by fitting a second-degree curve that includes the goal in 2020. The transition between this value and the future is made by adopting a Poisson curve whose average is the indicated time constant.

In the present work we have considered the values of this parameter indicated in Table 1.2

Table 12: Parameters for extrapolation of the thermal power plants contribution

Vapor Coal

Diesel

Natural Gas

Conventional Thermal Power Plants

Time constant

12

14

6

6

Participation 2020

3.0%

1.5%

10.0%

17.0%

  

Participation of Fuels for Electricity Generation in Public Power Plants

Vapor Coal / Projection/ Fuel Oil / Diesel Oil / Charcoal / Natural Gas/ Conventional Power Plants/ Projection

Figure 1.6: Projection of participation of conventional fuels in electricity generation in public power plants

 

Electricity Generation by Fuel

Vapor Coal / Fuel Oil / Diesel Oil / Charcoal / Natural Gas/ Conventional Power Plants/

Figure 1.7: Participation, in absolute values, of traditional thermal fuels in electricity production.

The need to increase thermal generation comes directly from the foreseen consumption data and is the basis for projection of thermal power plants to be constructed. The corresponding installed capacity depends also on the projection of the load factor in which the plants would operate. In Figure 1.8 the historical and the projected additional electric energy for each year are shown.

 

Additional Thermal Generation Annual Variation

Vapor Coal / Fuel Oil / Diesel Oil / Charcoal / Natural Gas/ Conventional Power Plants/ Projection

Annual Variation in TWh/year

 

Thermal Generation Annual Variation – Movable Average

Vapor Coal / Fuel Oil / Diesel Oil / Charcoal / Natural Gas/ Conventional Power Plants/ Projection

Figure 1.8 a and 1.8 b: Historical and foreseen variation of annual generation in conventional thermal power plants

In the lower part of Figure 1.8 b the movable average values are shown.

Figure 1.8 b shows the corresponding movable average that minimizes the annual variation of installed capacity use; these values will be useful in the projection of the capacity to be installed in order to satisfy demand and in comparison with other projections.

 

2. Electricity Generation from Thermal Power Plants and Fuel Demand for Generation