Before the end of 2022, the Mining and Energy Planning Unit (UPME) published the "Transmission Expansion Plan 2022-2036" VER-, "through which the necessary works for the incorporation of the second phase of renewables from the Department of La Guajira are defined, and works related to meeting the demand, which contribute to guaranteeing the reliability and security of the National Transmission System," the entity assures.
Indeed, the plan includes seven transmission works, among which the "Guajira Cesar Magdalena" project stands out.
This is a 600 kV HVDC line, VSC type, bipolar with metallic return, interconnecting the Colectora 2 -500 kV- substation in the Department of La Guajira with the Primavera 500 kV substation.
"The Caribbean concentrates the largest portion of the assigned capacity; the seven departments add up to 9,042 MW of NCRE (Non-Conventional Renewable Energy Sources) and conventional sources," says UPME.
And it warns that "currently the transport capacity of the existing network and its expansions is exhausted, conditioning the connection of new generation projects.
That is why the construction of this mega electrical project is proposed, which will allow the incorporation of 2,000 MW of generation in 2028 and an additional 1,000 MW in 2032 , and for this purpose the line will travel an approximate land route of 713 km .
Its commissioning date is December 2032 .
The costs associated with the project, considering possible delays, amount to USD$1,953,000,000 , but, according to calculations released by UPME, "benefits are projected from reduction of the marginal cost of energy, firm energy not committed, and emissions avoided worth USD$2,964,300,000, with a benefit-cost ratio of 1.64 times. 
Works in Córdoba Two projects stand out within the 2022-2036 Transmission Expansion Plan: a- Second circuit Cerromatoso - Sahagún - Chinú 500 kV When performing a simulation of the impact of a disconnection event on both circuits associated with the Sahagún 500 kV Substation, the following is observed:
- Sudden drop in system frequency, which causes the EDAC to activate up to its fourth stage.
- Even with the EDAC operating, the system frequency drops to a minimum of 58.72 Hz before stabilizing.
- According to CNO Agreement 1515 of 2022, the activation of the fourth stage of the EDAC implies the disconnection of 20% of the demand of the SIN.
This involves the addition of a new 500 kV circuit between Cerromatoso and Chinú to the Sahagún substation to achieve greater reliability and safety, taking into account the new capacities to be connected in the aforementioned substation.
The project's commissioning date is December 2025.
Valuing the costs in UCs according to CREG resolutions 011 of 2009, a value of USD$9,457,313.49 is obtained.
The proposed work provides a significant increase in reliability at the Sahagún 500 kV substation, as well as to the generation with assigned capacity at said substation, and the benefit-cost ratio is 2.57 times with a probability of 78.97%.
In the high-dispatch scenario at Sahagún 500 kV, the proposed project can have a benefit-cost ratio of up to 10.2 times. b- Central cut in diameter one of the Chinú 220 kV substation. The Chinú 220 kV substation, located in the department of Córdoba, was designed and built to operate in a breaker-and-a-half configuration; however, due to the way the Chinú 500/220 kV transformer and the Chinú-Montería 220 kV line are connected, it is currently operating in a ring configuration.
The connection of a new user is scheduled for 2023, who will be connected in diameter one, in which the Chinú 500/220 kV transformer is also connected; however, this diameter does not have a central cut.
Therefore, the installation of the central cut of diameter one of the Chinú 220 kV substation is proposed.
The project's commissioning date is November 2023.
Valuing the costs in UCs according to CREG resolutions 011 of 2009, a value of USD$431,718.73 is obtained.
The proposed work allows for improved reliability of the Chinú 220 kV substation by preventing the loss of additional generation when the Chinú 500/220 kV transformer goes offline or vice versa; additionally, it allows the substation to begin operating in the configuration for which it was designed and the correct connection of the 99.9 MW generation project by the date on which it is planned.
The estimated benefits of the project are USD$30,911,568.30, resulting in a benefit-cost ratio of 71.6011. Works include the Valle Bahía compensation bay, a central cut for the new diameter, a transformer bay on diameter two (2), and differential protection for the busbar at the San Marcos 500 kV substation.
In the area of influence of the San Marcos 500 kV Substation, for the years 2024 and 2029, voltages with values outside the ranges admissible by the current regulation are present, in a scenario of minimum demand and generation, that is, the Alférez, San Marcos, Virginia, Cartago and Yumbo substations.
To improve these voltage profiles, it is necessary to dispatch up to 6.1 Equivalent Units of generation in the area, which could cause an additional cost to the system and its users.
Therefore, the following project is proposed:
- A bay for the installation of the 120 MVAr rod reactor at the San Marcos 500 kV substation.
- A central cut for the new diameter of the San Marcos 500 kV substation where the bus reactor will be installed.
- A transformer bay to complete diameter 2 of the San Marcos 500 kV substation.
Valuing the costs in UCs according to CREG resolutions 011 of 2009, a value of USD$9,456,773.20 is obtained.
The proposed project allows for the completion of the second diameter of the San Marcos 500 kV substation to operate in its designed configuration (one and a half breakers) instead of a ring configuration, and reduces the number of equivalent generating units, resulting in lower operating costs. The benefits amount to USD$87,007,796, giving it a benefit-cost ratio of 9.6. Work in Bolívar : Third Transformer at the Bolívar 500/220 kV Substation. In the event of a transformer failure at the Bolívar 500/220 kV substation, the remaining transformer experiences an overload close to the emergency limit defined for that asset.
Therefore, the installation of a third transformer in the Bolívar 500/230 kV 450 MVA substation is proposed.
The project's commissioning date is June 2026.
Valuing the costs in UCs according to CREG resolutions 011 of 2009, a value of USD$11,626,420.65 is obtained.
The proposed project allows for the expansion of new generation capacity by 650 MW, with benefits amounting to USD$183,444,000, resulting in a benefit-cost ratio of 15.77 times.
Even with the generation connection with capacities on the order of 100 MW, the project remains viable with a benefit-cost ratio greater than 1. Works in Risaralda Installation of a second transformer in the La Virginia 500/230 kV substation by relocating the existing transformer.
With the shutdown of the La Virginia San Marco 500 kV Circuit, an overload is generated in the only La Virginia 500/230 kV transformer, due to the high flow of power from the center of the country, to meet the demand of the departments of Caldas, Quindío, Risaralda, Valle, Cauca, Nariño and the export to Ecuador.
This overload condition remains until the complete Southwest Reinforcement 500 kV expansion project, including the La Virginia Alférez 500 kV circuit, comes into operation starting in 2025.
In the years 2022, 2023 and 2024, to mitigate this overload condition, thermal generation outside the merit area must be dispatched, more specifically in the Cauca Valley, which must exceed 254 MW.
Therefore, it is proposed to transfer the 500/230 kV 450 MVA transformer to the La Virginia 500/230 kV substation, which is currently being remunerated to the Bogotá Energy Group (GEB).
This proposal is due to the delay in the commissioning of the complete Southwest Reinforcement (with the La Virginia - Alférez 500 kV circuit), which would involve the transfer of one of its 500/230 kV transformers from the Alférez 500 kV substation or the Norte 500 kV substation to the La Virginia 500/230 kV substation.
The project's commissioning date is December 2024.
Given that the transformer is already paid for, no costs associated with the project are considered.
The proposed project allows for mitigating the restriction during the years 2023, 2024 and until the full operation of the Southwestern Reinforcement in 2025.
The project will be carried out depending on the availability of space at the La Virginia 500/230 kV substation and the agreements reached between GEB and the substation owner. Work in Arauca: Reconfiguration of the Banadía 230 kV substation from a single busbar to a main busbar plus a transfer busbar (BPT).
Given the radiality conditions in the Arauca subarea, restrictions are identified in the system that produce unmet demand conditions in the face of contingencies of the following elements of the system.
Therefore, the reconfiguration of the Banadía 230 kV substation from Single Busbar to Main Busbar plus Transfer Busbar - BPT is proposed. This work is proposed in consideration of the entry into operation of the Alcaraván Banadía La Paz 230 kV work adopted in the Reference Expansion Plan Generation Transmission 2016-2030.
The project's commissioning date is November 2025.
Valuing the costs in UCs according to CREG resolutions 011 of 2009, a value of USD$7,973,157 is obtained.
The proposed work together with the development of the Alcaraván Banadía La Paz 230 kV project, which is intended to be executed through the expansion mechanism (CREG Resolution 193 of 2020, which modifies CREG Resolution 022 of 2001) allows the connection of 120 MW of generation, and the saving of unsupplied energy, contributing to the elimination of the low reliability of the Arauca subarea system.