Medium-voltage direct current: what CIGRE has documented and what already exists in Mexico

Bajío Ventures · July 2026

Two CIGRE publications — Technical Brochure 793 (2020) and the ELECTRA 323 summary of TB 875 (2022) — set out the state of medium-voltage direct current (MVDC) for distribution grids. This is what they contain, with figures and dates.

Why it matters

In Mexico, the constraint on connecting new industrial load — plants, data centres, storage — is not generation but the capacity available in the distribution grid and in the transmission links that feed it. Building new circuits takes years; existing corridors and rights of way are the scarce asset. The two CIGRE publications describe a technology whose main effect is exactly that: drawing more power from conductors already in place and controlling where it flows. That is why the subject concerns the industrial-park owner and the economy secretary, not just the utility’s engineer.

What it is

MVDC operates between 1.5 kV and 100 kV, between the low voltage of an industrial building and high-voltage transmission. It works like a smaller-scale HVDC: power-electronic converters that control power flow point to point, or between several points, over conductors that already exist.

What TB 793 measures

With the same conductor and the same installation, a DC circuit carries 1.63 times the power of the equivalent AC circuit. The study also reports lower short-circuit current, better power quality and no synchronisation issues. The main applications it identifies: renewable collection, reinforcement of dense urban grids, and connection of DC loads — battery storage, fast EV charging, data centres.

What is missing

Both documents say it plainly: there is no international MVDC standard. DC circuit breakers, low-cost DC/DC converters and standardised voltage levels are still under development. Angle DC, in Wales, was fully commissioned in 2022 and showed that an MVDC link can meet the connection codes of an existing AC network; it is the project that prompted TB 875.

What exists in Mexico

TB 793 records the Eagle Pass link: 36 MW, ±15.9 kV, back-to-back VSC converters between the United States and Mexico, status “completed”. Its role is to stabilise voltage and allow power exchange between two systems that are not synchronised. By CIGRE’s own inventory, it is one of thirteen MVDC projects implemented worldwide at the time of the survey.

The size of the opportunity

ELECTRA 323 estimates a potential market of USD 88 billion from 2025 across distribution, industrial applications, transport and marine energy collection. TB 793 itself identifies the driving force as the growth of distributed generation and of DC loads: batteries, electric vehicles and data centres — the three loads now knocking on the door of the Bajío’s industrial parks. The technology exists, a link is operating on the northern border and standardisation is under way; what these two texts document is that the conversation has moved from the laboratory to the grid.

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Acknowledgement. Bajío Ventures thanks Víctor Sierra, of CIGRE’s “One Grid” group, for his technical leadership and the exchange of documents that gave rise to this note.

Sources: CIGRE TB 793 — Medium voltage direct current (MVDC) grid feasibility study, WG C6.31, February 2020 · TB 793 summary in ELECTRA 309 · CIGRE ELECTRA No. 323 — Medium Voltage DC System (TB 875, JWG C6/B4.37), August 2022 · Full TB 875, public copy from SP Energy Networks

Bajío Ventures — a Mexican energy-infrastructure investment group based in Guanajuato: capital, a data platform on the region’s industrial base, and a German industrial channel, with its own advisory presence in Berlin.