Josemaría Power Corridor
Who Controls Argentina’s Copper Grid?

The case sits at the centre of Argentina’s emerging copper economy. The country’s advanced projects are not simply waiting for financing and permits. They are competing for roads, water, grid nodes, transformer capacity and rights over infrastructure built in earlier development cycles.

That changes the commercial question. Josemaría does not merely require electricity. It requires a regulatory structure capable of converting a private mining demand into permanent regional infrastructure without making the same infrastructure inaccessible to the next project.

Why Josemaría needs a new power corridor

Vicuña Corp. presented an initial demand of approximately 260 MW for Josemaría Phase 1. At the June hearing, the company said demand could later increase to around 400 MW and approximately 700 MW through successive stages of the district plan.

The initial load is already industrially significant. Vicuña described the project as electricity-intensive because crushing, grinding and mineral processing require a robust connection point, stable voltage and sufficient short-circuit strength. The current regional system cannot simply absorb a load of this scale without major transport works.

The corridor is therefore not an optional improvement. Vicuña described the federal access and expansion approval as a critical condition for converting project preparation into executable infrastructure contracts, construction schedules and eventual operations.

The infrastructure package has five layers

The connection architecture extends from the mine to the national interconnected grid. It combines project-owned facilities, authorized federal transmission assets and an upgrade of an existing line.

Once enabled, the federal 500 kV works would enter the SADI and be operated and maintained by Transener. Vicuña promotes and finances the expansion; it does not become the transmission operator.

The design also creates optionality beyond the mine. Chaparro includes space for future transformation and possible interconnections toward La Rioja Sur and Catamarca. Rodeo provides room for further expansion, while the new system could support future mining demand and renewable generation in northern San Juan.

Resolution 330 confirmed the priority structure established in Resolution 79

Resolution 79/2026 established three priority layers for Vicuña. After the June public hearing and the objections summarized in this analysis, Resolution 330/2026 ratified those priorities rather than narrowing them.

CAMMESA’s calculation treated 71 per cent of an assumed 854 MVA total corridor capacity as remaining. Ninety per cent of that remainder produces approximately 545.7 MVA. Resolution 330 explicitly ratified this priority on Nueva San Juan–Rodeo and the priorities on the new Rodeo–Chaparro line and Chaparro substation.

The regulator also maintained the distinction around Rodeo’s new 600 MVA transformer. The earlier decision had not granted Vicuña equivalent priority over that transformer because its loading was not considered to depend appreciably on Vicuña’s demand. Resolution 330 left that structure intact.

The case contains two legally different infrastructures

The strongest objection separates the corridor into a pre-existing section and a new section.

Rodeo–Chaparro is a new line. It does not yet exist, and Vicuña proposes to finance its 167 kilometres of 500 kV infrastructure together with the new Chaparro node. A priority right can therefore be defended as an incentive for creating capacity that would otherwise not be built.

Nueva San Juan–Rodeo already exists. The physical line was built through a mixture of federal and provincial funds, electricity-user contributions and earlier mining payments. Vicuña’s project would change the terminal configuration and energize the link at 500 kV, but it would not create the entire corridor from nothing.

This distinction is the core of the case. A single regulatory priority was applied across infrastructure with different financing histories and different relationships to Vicuña’s demand.

Vicuña’s argument: priority makes private infrastructure bankable

Vicuña’s position is that a mine cannot finance and schedule a multibillion-dollar development around uncertain electricity access. The company therefore needs secured availability compatible with the life of the project and the successive stages of its demand.

At the hearing, Vicuña argued that Resolution 79 did not give it control over San Juan’s electricity system and did not abolish open access. It described the priority as applying to incremental capacity generated by specific works that it promotes and finances. Other users could still request further expansions.

This is the investment-incentive case. Without a protected right to use the capacity it pays to create, a private developer could face a free-rider problem: it finances the infrastructure, while later users consume the capacity without sharing the original risk or cost.

The Instituto Argentino de la Energía General Mosconi supported this underlying logic at the hearing. Its contribution was not a blanket endorsement of every priority term, but a warning that immediate unrestricted access can destroy the incentive for private transmission investment.

San Juan’s position: the new demand must internalize system costs

EPRE San Juan supports mining development but conditioned its opposition on a system-mitigation agreement.

The provincial regulator argued that Vicuña’s load and the voltage conversion would change regional power flows, increase pressure on transformation infrastructure and potentially advance other network investments. Those effects should not be transferred to households, commerce or unrelated industries through tariffs or deteriorating service quality.

EPRE also argued that today’s corridor resulted from long-term planning and mixed financing. At the hearing it stated that earlier mining companies had contributed a total of US$133.8 million to provincial public funds used to expand and consolidate the network. That number is EPRE’s stated historical accounting position, not an independent valuation performed by Econosur.

The requested solution was not simply rejection. EPRE sought:

• a formal mitigation agreement between Vicuña and San Juan;
• internalization of system costs caused by the new mining demand;
• protection of service reliability for existing users;
• recognition of earlier financing rights; and
• availability of capacity beyond Vicuña’s actual requirements for other projects.

Los Azules challenges the model behind the capacity

Andes Corporación Minera, the Argentine project company for Los Azules, did not reject the principle of priority on newly financed capacity. It challenged the technical base and the extension of that priority onto the existing trunk corridor.

The first objection concerns the 854 MVA capacity assumption. According to Resolution 219 and the hearing transcript, Andes argued that the number was not a measurement under current operating conditions. It came from a model that treated Nueva San Juan as an “infinite power bus” — a strong-node assumption that CAMMESA itself described as not matching the system’s current condition and as dependent on future generation, synchronous compensation or other works outside Vicuña’s package.

The second objection is multiuser planning. A study commissioned by Andes modelled simultaneous 2030 demand from:

Andes stated that its study produced a corridor capacity between 645 and 745 MVA rather than 854 MVA. Under those assumptions, the 545.7 MVA priority would absorb between 73.2 and 84.6 per cent of the modelled real corridor capacity, leaving 99 to 199 MVA for other users.

Andes therefore requested a narrower priority, periodic review, release of unused capacity, separate treatment of the existing Nueva San Juan–Rodeo section and the new Rodeo–Chaparro section, and an integrated regional study that includes other mining demand.

Earlier mines claim that financing created rights

The corridor was not financed through one clean public-private transaction. Several earlier projects claim rights based on agreements, provincial legislation and direct contributions.

These claims are not equivalent to a final federal capacity award. They demonstrate that the corridor already carries a contractual and political history that cannot be reduced to a simple calculation of unused megavolt-amperes.

La Rioja wants a future place in the network

La Rioja’s intervention gives the case an interprovincial dimension. The province sought recognition of its earlier participation and requested that the Chaparro design preserve the technical possibility of a future 500 kV connection toward La Rioja Sur.

Its position was that a final approval should not close regional expansion options or leave La Rioja to finance all future works created by the new system configuration. Chaparro’s planned space for future links toward La Rioja and Catamarca therefore has regulatory as well as engineering significance.

The power dispute mirrors the separate road conflict around Vicuña. The deposit is located in San Juan, but major infrastructure decisions affect neighbouring provincial systems and create bargaining positions outside the immediate mine site.

The corridor tests Argentina’s new private-infrastructure model

Resolution 330 gives a clear regulatory answer to the immediate dispute: the federal regulator accepted the private-investment logic and ratified Vicuña’s priority rights while maintaining that they apply to incremental capacity rather than ownership or control of the public grid.

That decision does not remove the wider multiuser problem. As Los Azules, El Pachón, Hualilán and other projects advance, the system will still need rules and additional investment that reconcile private financing with open access and future demand.

A workable long-term model therefore still needs at least five elements:

This is why the corridor matters beyond one mine. Resolution 330 is now an observable precedent for how Argentina can authorize privately financed mining infrastructure that becomes part of a wider public system. The next test is whether later projects can connect without recreating the same capacity conflict.

The regulatory file describes a real supplier market

The proceeding is also a procurement map. Transener’s hearing presentation identifies engineering packages that go far beyond a line-construction contract.

The regulatory file describes technical requirements, not awarded contracts. Resolution 330 removes the main federal approval uncertainty for the transmission package, but supplier opportunity still depends on project sanction, detailed engineering, package design, financing and the procurement route selected by Vicuña, Transener and their contractors.

The distinction matters. Regulatory approval reveals a defined infrastructure requirement, but it does not identify the final EPC or EPCM structure, bidder list, qualification route or equipment awards. Those commercial details are not established by the public decision.

What remains open after Resolution 330

The regulatory decision therefore closes one question but opens the commercial phase. The corridor is authorized. What public information still does not show is the precise contracting sequence, supplier field, package timing and multiuser capacity picture that will determine who participates in execution and how quickly later projects can connect.