Energy and Emissions Matrix
1 - Introduction
Among the works developed by e&e we point out the Brazilian Energy Matrix calculation and the calculation of emissions due to the use of different energy sources in the various economic activities. Resuming this area, the present work analyzes the role of different energy sources, including nuclear energy, in electric energy generation in the country in a larger horizon.
2 – Aim of the 2020 Extension
The present work aims at supplying input for decision-making regarding the construction (or not) of the Angra III Nuclear Power Plant. If the decision is favorable, its start of operation should be around 2009. Its influence on the system would be felt in the next decade, hence the convenience of extending the analysis up to 2020.
Electric energy generation in the 2020 horizon should be inserted in the general framework of the Brazilian energy matrix and even in the world framework. A Brazilian energy matrix that would supply a strategic view of the Brazilian energy horizon in the next twenty years or the perspective of electric energy generation is not yet available.
In the preliminary proposal presented here it was envisaged to:
3 – Description
Programs developed for personal computers (using Visual Basic on Excel) were used. They permit to consider different hypothesis concerning the economy both in their macroeconomic and sectorial aspects in a relatively fast way.
The energy part utilized the equivalent energy concept that allows the substitution of energy sources and the progress concerning energy conservation in a relatively easy way.
The construction of the energy scenario, as noted, took into account the sectorial results and the energy sources of one “run” of the energy matrix for a scenario analogous to the present “reference” one.
The methodology used starts from the historical behavior of the equivalent energy/GDP ratio verified in Brazil that shows a remarkable regularity in the last 30 years. The ratio for the end of the period was chosen based on the historical data of the country, on the comparison with other countries and on results from other analyses.
In a similar way, the historical participation of the electric energy in the equivalent energy consumption and the comparison with other countries were examined. The result shows that Brazil has already a relatively important electricity participation and almost at the level of the developed countries.
The electric energy/GDP ratio has permitted a direct comparison between the methodologies as well as to simulate the demand using criteria equivalent to those of the Decennial Plan. The starting values were already very coherent with those of the Decennial Plan, which made its extension easy. The projected growths of the GDP, of the Equivalent Energy and of Electricity are shown in Tables 1 and 2 for the two considered scenarios.
Table 1: e&e Reference Scenario, annual variations
Table 2: Extended Decennial Plan Scenario, annual variations
In order to project the electric energy generation using the demand, it was necessary to estimate the losses of the system and the participation of net imports in the electric energy offer. In the case of the integrated system’s demand, the participation of self-producers was calculated separately. The values found are summarized in Tables 3 and 4.
Table 3: Gross Demand - e&e Reference Scenario
Table 4: Gross Demand - Extended Decennial Scenario
As can be verified, the scenarios were very conservative in what regards imports that would remain practically constant in the next decade. Significant gains in percent losses were not foreseen as well.
The present work maintained the basic premises of the Decennial Plan adapting the 2010 horizon to the changes that occurred in the economy and that were due to the electric energy supply crisis.
In the present case the interest is to discuss the participation of the different energy sources in electric energy generation in Brazil in a framework extended to the year 2020. It should be remembered that the probable scenarios for the next decade are already being used in order to determine the energy policy in other countries. The same must occur in Brazil.
In the present context it was considered convenient to use the three most competitive alternatives found in preliminary analysis of generation costs, namely hydroelectric, conventional thermal and nuclear power plants. Different participations of energy sources can be studied with the developed methodology.
The introduction of the conventional thermal power plants (non nuclear) was studied for the two participations previously mentioned, 10% and 16%.
The introduction of Angra III (to be added to the generation of the two already operating nuclear power plants) would not maintain the present nuclear participation in electricity generation since it would drop from the present 4% (4.8% in 2001) to 1.6% in 2020 in the Extended Decennial Plan.
In order to evaluate the generation capacity necessary to satisfy future demand, the capacity factor of the different types of power plants were projected. These factors would tend to 53% for the hydraulic plants, 58% for the conventional thermal plants and 60% for the nuclear plants.
Within the projected demand framework, several hypotheses regarding the three mentioned generation forms were examined, for the different available energy sources. As a basic hypothesis it was considered the introduction of thermal conventional plants in order to reach the 16% participation in 20 years. In the nuclear case we have considered the situation with and without Angra III. In the first case the start of full operation was supposed to be 2009.
The projected generation capacity is coherent with the decennial plans and is adaptable to a smaller economic growth in the first years of the scenarios envisaged here (and to what already occurred after those plans were formulated). Each hypothesis supplied a projection of the needs of new electricity generation power plans whose composition varies according to the assumed velocity of thermal plants penetration. The results were compared with the planned power plants.
It was considered the need of introducing a practical limitation for the installation of hydroelectric plants due to the experience of other countries that have an important hydroelectric potential like Brazil.
Two limits were analyzed. The first one comes from an analysis of the system’s behavior that would indicate a hydraulic generation of about an average of 60 GW (installed 115 GW).
The second limit resulted from a comparison of generation costs that shows that around 58US$/MWh would make viable most part of the studied alternatives. It was assumed a ratio between the cost of the hydraulic electricity and the installed capacity. Using this ratio, this value would be reached with an installed capacity of 150 GW or an average annual generation of about 80GW.
The need of additional generation was studied considering two initial policies regarding thermal participation in the next two decades: that of the historical maximum (10% participation of thermal conventional plants in the generation) and that resulting from the present policy (16% participation of thermal plants in the generation).
By establishing a 150 GW limit for the installed hydraulic generation it becomes necessary to define an additional generation capacity that will be fulfilled by increasing the participation of the thermal plants (conventional or nuclear) or of alternative energies. In the case of the Extended Decennial Plan, the introduction of these additional plants would occur between 2014 and 2015. This limit takes into account the inertia regarding the transition between the hydraulic plants and plants of other type.
If this limit is considered a valid one, one can suppose that the option relative to the electricity generation policy can be divided in points: in the first one a limit is fixed for the desirable participation of conventional thermal plants and in the second one it is established the complementary demand using thermal plants or another available option.
This analysis procedure can incidentally coincide with the actual policy decision.
It was chosen a participation of thermal plants in the next years and before the end of this decade, preferably in the next five years when it will be necessary to make a decision regarding the complementation for the next decade.
4 - Conclusions regarding the 2020 approach
There is no consensus about the effective limit for the hydraulic generation but it is almost certain that the total installed capacity will have been exceeded at the start of the second decade of the present century. The decision relative to the nuclear plant participation in any of the studied scenarios will have to be made in the next 5 to 10 years. Studies regarding the eventual participation of nuclear energy in the Brazilian energy matrix are already necessary.
A discerning demand analysis in different scenarios, an analysis of the energy sources known and probable reserves in the country, a technological forecasting about the evolution of the generation process and a strategic analysis about electricity supply should be made in the next years.
While this analysis in not completed, it seems prudent to keep open the nuclear option in case the generation costs of Angra III when it is completed are close to the projected marginal costs for the end of the decade, Finally, it should be pointed out that the nuclear option continues to be the preponderant option in countries that need to increase their electricity production and that have the technological means and the material to do it.
Graphic Edition/Edição Gráfica:
Tuesday, 10 May 2011.