Economy
& Energy
No 23 December 2000 - January
2001
ISSN 1518-2932
No 23 emPortuguês
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Economy
& Energy |
No 23 em Português |
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Progress in the Energy Matrix and in the Emissions of Gases Causing the Greenhouse Effect Main
Page Preliminary
Evaluation for the 2000-2020 period
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1. Thermoelectric Generation in Public Power Plants1.1 Electricity Generation and Fuel ParticipationProvision of Electricity DemandProjection 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.
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)
1.2 Fuels ParticipationThe 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.
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.
Figure 1.4: Participation of the conventional thermal energy sources for electricity generation in public power plants
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 PlantsThe 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
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.
Thermal Generation Annual Variation – Movable Average .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
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