Conceptualización del sentido positivo.

Figure 5.15 shows the structure of the electric power sector for the Mexican Integrated Power System. As BALANCE does not perform a system expansion, in a typical ENPEP application, the expansion plan was determined by WASP (/DECADES) and DECADES then transferred to BALANCE. Using the BALANCE dispatch node and the thermal and hydro- unit nodes, BALANCE then dispatches the system unit-by-unit, and calculates unit-level generation, fuel consumption, and production cost for all existing and new units. As the BALANCE dispatch is using a somewhat different approach than the WASP dispatch, minor discrepancies may occur that are usually of no concern given the long time frame of the analysis. The existing capacity in 1999 in the National Power System was 35.7 GW, of which 27.97% was hydro capacity and 73.03% thermal capacity. After some additions and retirements, in 2001 total capacity of the National Power System was 38.5 GW, of which 25% was hydro and 75% thermal. Besides the additions and retirements during 2000 and 2001 there were additions under the modality of external energy producer, 484 MW in 2000 and 972.4 MW in 2001.

On the basis of the last prospective study for the Mexican power sector20, during 2002, some thermal units will be added representing an addition of 2,577 MM to the existing capacity. On the other hand, some thermal, hydro, geothermal units that are already under construction or committed will be added along the period 2003-2008. These additions, under the modalities of construction, adjudicated, in bidding process and entering into the bidding process, represent a total addition of 11,651 MW for the period 2003-2008. For the period 2002-2008, total committed capacity is 14,228 MW, 80% with the combined cycle technology and 13% on the basis of renewable sources and the projects under the modality of construction are already in commercial operation and represent 16% of the committed capacity.

Figure 5.11 Liquefied petroleum gas (LPG) distribution network.

Figure 5.12 Natural gas distribution network.

The lower part of Figure 5.15 shows the coal (COAL), fuel oil (FOIL), diesel (DIESE), nuclear (NUCL) and natural gas (NATG) energy supplies for electricity generation; on the lower-right-hand-side part the geothermal resource for electricity generation and at the left- hand-side the hydro sector for electricity generation (HYDRO). For more detail of the network:

• Coal is split into the dual units node (FMIX, with 6 units) and the coal units node (COAL, with eight units);

• Fuel oil is split into three generation nodes: dual units node (FMIX, with six units), fuel oil units node (FOSTE, with 23 units) and the third portion is send to the electricity transmission and distribution node (ELT&D) for use in the generation units at the isolated regions;

• Diesel is split into the diesel gas turbines units node (DSLTG, with 21 units) and the electricity transmission and distribution node (ELT&D) for use in the generation units at the isolated regions;

• Nuclear is split into the nuclear units node (NUCL, with two existing nuclear units); • Natural gas is split into four generation nodes: gas turbine units node (GASTU, with

six units), independent power producers units node (IPPS, with five units), combined cycle units node (CC-TG, with 130 units, 12 existing in 1999 and 118 for the projection period) and the four portion is send to the electricity transmission and distribution node (ELT&D) for use in the generation units at the isolated regions.

Figure 5.13 Coal and coke distribution network.

• The geothermal energy resource is split into two portions, the first portion is used at the geothermal units node (GEOTH, with five existing units and two to enter in operation by 2002; these two new units are the ones considered in the projection horizon but incorporated to the fixed system to avoid the creation of an additional category in the VARSYS module of WASP) located at the interconnected system and the second portion is send to the electricity transmission and distribution node (ELT&D) for use in the geothermal units located at the isolated regions.

• Hydro is split into the hydro units node (HYDRO, with 23 existing hydro units and five new expansion projects).

Figure 5.14 Nuclear distribution network.

It is important to mention that the main portion of the geothermal development for electricity generation is located at the isolated region of Baja California and that a very small portion of this geothermal development is located in two of the interconnected regions. In the discussion of Chapter 2 it was indicated that the capacity expansion include two geothermal units of 50 MW each and that they were included in the fixed system avoiding an additional category in the VARSYS module of the WASP model.

As was mentioned in Chapter 4, the Mexican power system is divided into nine regions in terms of generation regions, six of them are interconnected and three are isolated. Since, we are using the BALANCE dispatch for the interconnected system (Figure 5.15) and this dispatch is using a somewhat different approach than the WASP dispatch, minor differences could be expected.

On the other hand, the isolated21 regions are not connected to the rest of the system and, as a consequence, they can’t be connected to the BALANCE electric dispatch node, therefore the modeling of the isolated regions followed a slightly different approach. Figure 5.16 shows the electricity transmission and distribution sector and in the lower left-hand-side of the figure appears the modeling of these isolated regions using a combination of allocation, conversion process and resource nodes.

For the modeling of these isolated regions, Table 5.2 shows the split of the electrical capacity into the Interconnected System and the isolated regions. The comparison of Table 5.2 and Table 5.22 shows that, for the years 1997 to 1999, the total capacity in the system is the same

21 _{The isolated generation regions are Baja California, Baja California Sur and Northwest regions, in the years 2001 and 2002}

there were some efforts to reinforce the interconnection of the Interconnected System (six regions) with the Northwest region, therefore, it appears that the two Baja California regions are the only ones isolated.

and that, for the years 2000 and 2001, there is a difference due to the additions indicated at the notes in the table’s footnote.

On the other hand, the isolated22 regions are not connected to the rest of the system and, as a consequence, they can’t be connected to the BALANCE electric dispatch node, therefore the modeling of the isolated regions followed a slightly different approach. Figure 5.16 shows the electricity transmission and distribution sector and in the lower left-hand-side of the figure appears the modeling of these isolated regions using a combination of allocation, conversion process and resource nodes.

Figure 5.15 Electric power sector (interconnected system).

For the modeling of these isolated regions, Table 5.2 shows the split of the electrical capacity into the Interconnected System and the isolated regions. The comparison of Table 5.2 and Table 5.22 shows that, for the years 1997 to 1999, the total capacity in the system is the same and that, for the years 2000 and 2001, there is a difference due to the additions indicated at the notes in the table’s footnote.

The modeling approach for the isolated regions was to consider the fulfillment of the generation demand along the projection period rather than the expansion of capacity in those regions. Therefore, through the use of the processes, links and allocation nodes shown in the lower left-hand-side part of Figure 5.16 the renewable energy sources (hydro and geothermal) and the fossil energy sources (fuel oil, natural gas and diesel) are transformed into electricity and the generation demands for each of the isolated regions along the projection years are satisfied.

22 _{The isolated generation regions are Baja California, Baja California Sur and Northwest regions, in the years 2001 and 2002}

there were some efforts to reinforce the interconnection of the Interconnected System (six regions) with the Northwest region, therefore, it appears that the two Baja California regions are the only ones isolated.

Besides the inclusion of three additional resource nodes: solar (Rsol), minihydro (Mhyd) and Wind (Rwind), processes and allocations. Of these three resource streams, only the corresponding one to the wind resource was feed with data. The other two are ready for the necessary information, if available, and they correspond, respectively, to the possibilities of solar energy capture and its transformation into electricity and to the use of small hydro resources for electricity generation.

The rest of the nodes include, a resource node for electricity imports (ELimp), transport nodes, price nodes, sector and sub-sector nodes for the final demands of electricity.